Abstract:
A three-way dual seat valve having a valve body including mutually spaced apart annular first and second valve seats. Reciprocally mounted with respect to the valve body is a valve stem which carries within the valve body an annular, dual-faced valve stem gate. Each gate face thereof is sealingly engageable with a respective valve seat in response to reciprocal movement of the valve stem.

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to valves, including coolant valves typically used in automotive applications. More particularly, the present invention relates to a reciprocating, three-way dual seat valve. 
       BACKGROUND OF THE INVENTION 
       [0002]    Valves are ubiquitous in fluid flow systems to provide directional control of the fluid flow therewithin. Valves are used to open and close fluid flow directions, wherein the valve may function between a fully open and fully closed state, or may be progressive, wherein the state of opening is selectively somewhere therebetween so as to meter fluid flow. Valves may be two-way, controlling fluid flow with respect to an inlet and an outlet of the valve, or may be three-way, controlling fluid flow with respect to a pair of inlets and a single outlet of the valve or a pair of outlets and a single inlet of the valve. 
         [0003]    Valve sealing is important, and common strategy for sealing is with a face seal against a ball, cylinder, or sleeve. The seals wear due to frictional forces and scrub due to contamination and deposition. Some of these seals need tight tolerances based on their application which can result in high scrap rates. In automotive applications, cold coolant and ambient air temperature tends to require high forces to actuate the valve. Short life and premature leakage are the major issues on this style of valve. 
         [0004]    Needle and seat solenoid valves have high pressure drops and excessive energy consumption. Some recent valve designs of this kind utilize a “move and stop” movement versus a “move and hold” movement in order to reduce energy consumption. Pressure drop and energy consumption are the major detriments with this style of valve. 
         [0005]    With current valve technology in mind, what is needed is a valve which minimizes the seal surface, reduces or eliminates seal leakage and seal wear for the life of the valve, utilizes hydraulic forces innate to the fluid system to minimize energy consumption to effect tight sealing, provides a high fluid flow coefficient, and has the further ability to meter fluid flow. 
       SUMMARY OF THE INVENTION 
       [0006]    The present invention is a three-way dual seat valve which minimizes the seal surface, reduces or eliminates seal leakage and seal wear for the life of the valve, utilizes hydraulic forces innate to the fluid system to minimize energy consumption to effect tight sealing, provides a high fluid flow coefficient, and has the further ability to meter fluid flow. Accordingly, the three-way dual seat valve of the present invention has a particularly advantageous application to automotive coolant systems. 
         [0007]    The three-way dual seat valve according to the present invention has a valve body including mutually spaced apart annular first and second valve seats. Reciprocally mounted with respect to the valve body is a valve stem which carries within the valve body an annular, dual-faced valve stem gate. Each gate face thereof is sealingly engageable (that is, seatable) with a respective valve seat in response to reciprocal movement of the valve stem. In a preferred environment of use, an inlet of the valve body is disposed between the first and second valve seats, a first outlet of the valve body is disposed downstream of the first valve seat, and a second outlet of the valve body is disposed downstream of the second valve seat; however, the outlet-inlet arrangement may be otherwise. 
         [0008]    The valve stem is, for example, reciprocated by operation of a linear actuator in response, for example, to electronic programming and sensed data available to an electronic control module. When the valve stem gate is centrally disposed with respect to the inlet, fluid flows to both the first and second outlets, however as the valve stem gate is moved so as to approach one or the other of the valve seats, fluid flow becomes restricted at the approached valve seat to the outlet respectively thereat, whereby proportional fluid flow may be established if the valve stem gate is held separated at a selected separation distance from the approached valve seat. When the valve stem gate is seated at either of the first and second valve seats, the engaging gate face thereof sealingly abuts the valve seat, assisted by hydraulic pressure (when present) of the fluid, whereby fluid flow is prevented from passing through the now closed valve seat and only passes through the other, open, valve seat and its respective outlet. Upon movement of the valve stem in the opposite direction, the sealing of the other valve seat is effected by sealing abutment with the other gate face of the valve stem gate, and fluid flow is then possible only through the respectively other of the outlets. 
         [0009]    As the gate face of the valve stem gate separates from its respective valve seat fluid flow therepast will be relatively rapid, depending upon fluid pressure, due to the small annular separation distance between the valve seat and the valve stem gate, whereby any debris disposed thereat will be flushed away by the rushing fluid. Additionally, the diameter of the valve stem gate is preferably less than the diameter of valve body between the first and second valve seats, whereby the valve stem gate will not scrape the valve body during reciprocation, only sealing at a beveled (or tapered) surface which defines the valve seats. 
         [0010]    Accordingly, it is an object of the present invention to provide a three-way dual seat valve which minimizes the seal surface, reduces or eliminates seal leakage and seal wear for the life of the valve, utilizes hydraulic forces innate to the fluid system to minimize energy consumption during operation of the valve, provides a high fluid flow coefficient, and has the further ability to meter fluid flow. 
         [0011]    This and additional objects, features and advantages of the present invention will become clearer from the following specification of a preferred embodiment. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]      FIG. 1  is a partly sectional side view of a three-way dual seat valve according to the present invention, showing an electro-magnetic actuation system therefor, further showing a valve stem gate thereof at a neutral position with respect to first and second valve seats, and yet further showing an interface of the three-way dual seat valve with a fluid flow system depicted in phantom. 
           [0013]      FIG. 2  is a sectional view, seen along line  2 - 2  of  FIG. 1 . 
           [0014]      FIG. 3  is a sectional view, seen along line  3 - 3  of  FIG. 1 . 
           [0015]      FIG. 4  is a sectional view of the three-way dual seat valve of  FIG. 1 , wherein now the valve stem gate is seated at the first valve seat. 
           [0016]      FIG. 5  is a sectional view, seen along line  5 - 5  of  FIG. 4 . 
           [0017]      FIG. 6  is a sectional view, seen along line  6 - 6  of  FIG. 4 . 
           [0018]      FIG. 7  is a sectional view of the three-way dual seat valve of  FIG. 1 , wherein now the valve stem gate is seated at the second valve seat. 
           [0019]      FIG. 8  is a sectional view of the three-way dual seat valve of  FIG. 1 , wherein now the valve stem gate is separated a small distance from the second valve seat. 
           [0020]      FIG. 9  is a sectional view, seen along line  9 - 9  of  FIG. 8 . 
           [0021]      FIG. 10  is a sectional view of a three-way dual seat valve similar to  FIG. 1 , wherein now the first and second valve seats (rather than the stem gate) are provided a valve seal. 
           [0022]      FIG. 11  is a sectional view of a three-way dual seat valve similar to  FIG. 1 , wherein now the first and second valve seats and the valve gate are provided with a valve seal. 
           [0023]      FIG. 12  is a sectional view of a three-way dual seat valve similar to  FIG. 1 , wherein now none of the first and second valve seats and the valve gate are provided with a valve seal. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0024]    Referring now to the Drawings,  FIGS. 1 through 12  depict various exemplary aspects of the structure and function of a three-way dual seat valve according to the present invention. 
         [0025]    Referring firstly to  FIGS. 1 through 9 , a three-way dual seat valve  100  according to the present invention will be detailed. 
         [0026]    The three-way dual seat valve according to the present invention includes a valve body  102  which, for purposes of manufacture, is composed of first and second valve body members  102 ′,  102 ″ which are mutually welded, threaded or otherwise sealingly joined and mechanically affixed. Within the valve body  102  is a pair of mutually separated annular valve seats, a first valve seat  104  and a second valve seat  106 , each being preferably characterized by an annular bevel or taper  108 . A medial valve body portion  110  of the valve body  102  is disposed between the first and second valve seats  104 ,  106 . A first distal valve body portion  112  of the valve body  102  is disposed adjoining the first valve seat  104  in juxtaposed relation to the medial valve body portion  110 . A second distal valve body portion  114  of the valve body  102  is disposed adjoining the second valve seat  106  in juxtaposed relation to the medial valve body portion  110 . 
         [0027]    A valve stem  120  passes through the valve body  102  and exits at the second distal valve body portion  114 , guided and sealed by gland  122  composed of packing  124  retained by a cap  126 . The exiting portion of the valve stem  120  is connected with a linear actuator  130 , most preferably an electro-magnetic actuator which is, for example, actuated in response to a signal from an electronic control module  132  having programming which reacts in a predetermined manner to data sensed by one or more sensors  134 . 
         [0028]    Guidance of reciprocation of the valve stem  120  in response to activation of the actuator  130  is provided additionally by a valve stem guide  136  which is attached to the first distal valve body portion  112 . As best shown at  FIG. 3 , the valve stem  120  passes through a stem guide opening  138  which is defined by an annular stem guidance collar  140  supported by a plurality of stem guide arms  142  which connect to an annular stem guide attachment collar  144  affixed to the first distal valve body portion. The stem guide arms  142  are separated to provide a fluid flow passage  146  through the valve stem guide  136 . 
         [0029]    The valve stem  120  carries within the medial valve body portion  110  of the valve body  102  an annular, dual-faced valve stem gate  150 , having a first gate face  152  which is sealingly seatable with respect to the first valve seat  104 , and further having a second gate face  154  which is sealingly seatable with respect to the second valve seat  106 , the seating being in response to reciprocal movement of the valve stem  120  via the actuator  130 . 
         [0030]    A first fitting  160  is connected with the valve body  102  with respect to the medial valve body portion  110 , being disposed preferably centrally between the first and second valve seats  104 ,  106 ; a second fitting  162  is connected with the valve body  102  at the first distal valve body portion  112 ; and a third fitting  164  is connected with the valve body  102  at the second distal valve body portion  114 . In the preferred environment of use of the three-way dual seat valve  100 , the first fitting  160  is an inlet of a fluid flow system  200  disposed upstream of the first and second valve seats  104 ,  106 , the second fitting  162  is an outlet of the fluid flow system disposed downstream of the first valve seat  104 , and the third fitting  164  is an outlet of the fluid flow system disposed downstream of the second valve seat  106 . However, the outlet-inlet assignment of the fittings may be otherwise. 
         [0031]    When the valve stem gate  150  is centrally disposed with respect to the first fitting  160 , as shown at  FIG. 1 , fluid flows from the first fitting (serving as the inlet) to both of the second and third fittings  162 ,  164  (both serving as outlets). In response to activation of the actuator  130 , the valve stem  120  reciprocates in one direction or the other and in so doing approaches one or the other of the valve seats  104 ,  106 . As this occurs, fluid flow becomes restricted at the approached valve seat and, consequently also with respect to the outlet respectively thereat. In this manner proportional fluid flow may be established if the valve stem gate  120  is held separated at a selected separation distance from the approached valve seat  104 ,  106  (see  FIG. 8 ). 
         [0032]    When the valve stem gate is seated at either the first valve seat  104 , as shown at  FIG. 4 , or at the second valve seat  106 , as shown at  FIG. 7 , the respectively engaging first or second gate face  152 ,  154  sealingly abuts the valve seat, assisted by hydraulic pressure (when present) of the fluid. In this regard with respect to  FIG. 4 , fluid flow is prevented from passing through the now closed first valve seat  104  and only passes through the other, open, second valve seat  106  and its respective outlet fitting  164 . Upon movement of the valve stem  120  in the opposite direction, as shown at  FIG. 7 , fluid flow is prevented from passing through the now closed second valve seat  106  and only passes through the other, open, first valve seat  104  and its respective outlet fitting  162 . 
         [0033]    Referring now in particular to  FIG. 8 , as either of the first and second gate faces  152 ,  154  separate from its respective valve seat  104 ,  106  fluid flow therepast will be relatively rapid, depending upon fluid pressure, due to the small annular separation distance between the valve seat and the valve stem gate  150 , whereby any debris disposed thereat will be flushed away by the rushing fluid. 
         [0034]    As can be appreciated by reference to  FIG. 2 , the outer diameter  170  of the valve stem gate  150  is preferably less than the inside diameter  172  of medial valve body portion  110 . Accordingly, as can be appreciated by reference additionally to  FIG. 1 , the valve stem gate will not scrape the valve body  102  during reciprocation between the first and second valve seats  104 ,  106 , only sealing at a beveling or taper  108  which defines the respective valve seat. 
         [0035]    Additionally, the medial valve body portion  110 , the first distal valve body portion  112  and the second distal valve body portion  114  are cross-sectionally sized with respect to that of the first, second and third fittings such that fluid flow has a high flow coefficient within the valve body  102 . In this regard, the cross-section of the first distal valve body portion  112  is larger than the cross-section of the second fitting  162  such that the fluid flow passage  146  is cross-sectionally sized with respect to that of the second fitting such that the high coefficient of fluid flow is provided. 
         [0036]      FIGS. 1 through 9  depict the three-way dual seat valve  100  according to the present invention having a valve seal  180 , as for example an elastomeric material, disposed at the valve stem gate  150 . In this regard the valve seal  180  is an overmold of the valve stem gate core  156  of the valve stem gate  150  jointly at the first and second gate faces  152 ,  154 . However, as shown at  FIG. 10 , the three-way dual seat valve  100 ′ of the present invention may have a valve seal  182  disposed, preferably as an overmold, at the first and second valve seats  104 ′,  106 ′, and the valve stem gate  150 ′ is free of a valve seal. However further, as shown at  FIG. 11 , the three-way dual seat valve  100 ″ of the present invention may have a valve seal  184  disposed, preferably as an overmold at both the valve stem gate  150 ″ and the first and second valve seats  104 ″,  106 ″. Indeed, as shown at  FIG. 12 , the three-way dual seat valve  100 ′″ of the present invention may have no valve seal at both the valve stem gate  150 ′″ and the first and second valve seats  104 ′″,  106 ′″, wherein the valve stem gate and the first and second valve seats can be composed of similar material, or harder or softer material collectively or respectively, depending on the environment of use of the present invention. 
         [0037]    To those skilled in the art to which this invention appertains, the above described preferred embodiment may be subject to change or modification. Such change or modification can be carried out without departing from the scope of the invention, which is intended to be limited only by the scope of the appended claims.