Abstract:
A selector valve for independently controlling fluid between a first passage, a second passage, and a common passage, comprising: a valve housing comprising an inner chamber in communication with the outlet, having a first valve seat in communication with the first inlet and a second valve seat in communication with the second inlet, a shaft slidably extending through the housing between the first and second valve seats; first and second valve poppets slidably mounted upon the shaft within the inner chamber, each having valve faces for seating against the first and second valve seats; and a spring coaxially located around the shaft between the first and second valve poppets, pushing against the inner surfaces of the first and second valve poppets, biasing the first valve poppet and the second valve poppet away from each other and toward the first valve seat and the second valve seat.

Description:
REFERENCE TO RELATED APPLICATIONS 
     This application claims one or more inventions which were disclosed in Provisional Application No. 61/297,988, filed Jan. 25, 2010, entitled “EXHAUST GAS SELECTOR VALVE FOR AN INTERNAL COMBUSTION ENGINE”. The benefit under 35 USC §119(e) of the United States provisional application is hereby claimed, and the aforementioned application is hereby incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention pertains to the field of selector valves. More particularly, the invention pertains to an exhaust gas recirculation and exhaust gas bypass selector valve for an internal combustion engine. 
     2. Description of Related Art 
     Current technology utilizes two separate control valves: one valve to control exhaust gas from the cooler to the intake manifold and a second bypass valve to control exhaust gas from the exhaust manifold to the intake manifold bypassing the exhaust gas cooler. Current technology adds complexity to the electronic control module and requires multiple output channels to control the two independent valves. 
     SUMMARY OF THE INVENTION 
     In accordance with an embodiment is a selector valve for independently controlling fluid between a first passage, a second passage, and a common passage. The selector valve includes a valve housing comprising an inner chamber in communication with the outlet, having a first valve seat in communication with the first inlet and a second valve seat in communication with the second inlet. The first valve seat and the second valve seat are coaxially located along an axis. A shaft slidably extends through the valve housing along the axis between the first valve seat and the second valve seat. A first valve poppet is slidably mounted upon the shaft within the inner chamber, and has a valve face for seating against the first valve seat, and an inner surface and a second valve poppet is slidably mounted upon the shaft within the inner chamber, and has a valve face for seating against the second valve seat, and an inner surface. A spring is coaxially located around the shaft between the first valve poppet and the second valve poppet, pushing against the inner surface of the first valve poppet and the inner surface of the second valve poppet, biasing the first valve poppet and the second valve poppet away from each other and toward the first valve seat and the second valve seat. 
     When the shaft is in a central position, the spring biases the first valve poppet against the first valve seat and the second valve poppet against the second valve seat, restricting fluid flow from the first inlet and the second inlet to the outlet. When the shaft is moved in a first direction from the central position, an actuating member on the shaft contacts the valve face of the first valve poppet, moving the first valve poppet toward the second valve poppet, such that a fluid path is opened from the first inlet past the first valve seat to the outlet. When the shaft is moved in a second direction from the central position, an actuating member on the shaft contacts the valve face of the second valve poppet, moving the second valve poppet toward the first valve poppet, such that a fluid path is opened from the second inlet past the second valve seat to the outlet. 
     In one embodiment, the first passage and the second passage are inlet passages and the common passage is an outlet passage. 
     In another embodiment, the first passage and the second passage are outlet passages and the common passage is an inlet passage. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
         FIG. 1  shows an exhaust gas selector valve of an embodiment in the present invention. 
         FIG. 2  shows a cross-section of  FIG. 1  along line  2 - 2  of the exhaust gas selector valve of an embodiment of the present invention. 
         FIG. 3  shows a central position of the exhaust gas selector valve of an embodiment in the present invention. 
         FIG. 4  shows a first position of the exhaust gas selector valve of an embodiment in the present invention. 
         FIG. 5  shows a second position of the exhaust gas selector valve of an embodiment in the present invention. 
         FIG. 6  shows the first position of the exhaust gas selector valve and the diameters of the valve poppets of the valve of an embodiment in the present invention. 
         FIG. 7  shows an alternate embodiment of the exhaust gas selector valve of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIGS. 1-6  show an actuated exhaust gas selector valve  2  of an embodiment of the present invention that independently controls exhaust gas flow to a common outlet. Referring to  FIG. 2 , the exhaust gas selector valve  2  has a shaft  12  that extends through the valve and is actuated via actuator  10 . The actuator  10  may be hydraulic as shown in  FIG. 2 , a pneumatic actuator, a solenoid, or an electric motor driven via a cam to linear motion, a gear transmission set to linear motion, or a combination of both, or any other device that provides linear motion. Additionally, the actuator  10  may move the shaft  12  between positions proportionally, in increments or from position to position. 
     The exhaust gas selector valve  2  has two inlet passages, a first inlet passage  14  allowing communication between the EGR cooler  7  and a venturi  8  in communication with the exhaust manifold  6 , and a second inlet passage  30  allowing communication between the exhaust manifold  6  and the exhaust gas selector valve  2 . The exhaust gas selector valve  2  has a common outlet passage  16  that is in communication with the intake manifold  5 . 
     The valve  2  has a housing  44  with an inner diameter defining an inner chamber  48  in communication with the common outlet passage  16 . The inner chamber  48  is further defined by a first valve seat  26  and a second valve seat  24 . The first inlet passage  14  is in communication with the inner chamber  48  through the first valve seat  26 . The second inlet passage  30  is in communication with the inner chamber  48  through second valve seat  24 . The diameter  32  of the first valve seat  26  and the diameter  36  of the second valve seat  24  may be equal to each other, or one of the diameters may be smaller or larger than the other. 
     Within the inner chamber  48  of the exhaust gas selector valve  2  are two valve poppets  18 ,  20  slidably moveable, independent of each other coaxially along an axis of the shaft  12 . The linear movement of the shaft actuates the poppets  18 ,  20  through actuating members  13 ,  15 . The actuating members may be a retaining ring, screw, shoulder of the shaft or any other device that creates an extended feature beyond the diameter of the shaft  12 . 
     The first valve poppet  18  is slidably received by the second valve poppet  20  such that diameters  34  and  41  of the two valve poppets  18 ,  20  interface  50  with each other forming and defining a pressure chamber  21  between the two valve poppets  18 ,  20  as shown in  FIG. 6 . At least one of the valve poppets  18 ,  20  has a pressure passage  19  to the pressure chamber  21 . Within the pressure chamber  21  and between the two valve poppets  18 ,  20  is a spring  22  biasing the two valve poppets  18 ,  20  apart and towards their respective valve seats  24 ,  26 , in other words, the spring  22  biases a first valve face  17  of the first valve poppet  20  towards the first valve seat  26  and a second valve face  23  of the second valve poppet  18  towards the second valve seat  24 . The pressure chamber formed  21  between the two valve poppets reduces the spring force required for spring  22  to maintain positioning of the poppet valves  18 ,  20 . The pressure chamber  21  also reduces the force in which the actuator  10  needs to pull or push shaft  12  to linearly move or actuate the poppet valves  18 ,  20 , and reduces pressure forces present on the valve poppets  18 ,  20 . The cross-sectional areas of each of the pressure chamber  21  formed between the inner surfaces of the valve poppets  18 ,  20  may be smaller, equal to, or larger than the diameters/areas  32 ,  36  of the first and second valve seats  26 ,  24 . In  FIGS. 2-6 , the first valve poppet  20  is shown as being slidably received within the second valve poppet  18 , but the second valve poppet  18  could be slidably received by the first valve poppet  20 . 
     A piston ring or seal  51  may be present at the interface  50  between the two valve poppets  18 ,  20 , for example between diameter  34  of the first valve poppet  20  and the inner diameter  41  of the second valve poppet  18  to reduce the leak path between the pressure chamber  21  formed between the two valve poppets  18 ,  20  and the inner chamber  48  to the common outlet  16 , exiting the exhaust gas selector valve  2 . 
     When the first valve face  17  of the first poppet  20  seats on the first valve seat  26 , the first inlet passage  14  is sealed off from the inner chamber  48  of the exhaust gas selector valve  2  and any exhaust gas that passes through the EGR cooler  7  and the first inlet passage  14  is prevented from mixing with the exhaust gas from the second inlet passage  30  and flowing out the common outlet passage  16 . When the second valve face  23  of the second poppet  18  seats on the second valve seat  24 , exhaust gas from the second inlet passage  30  is sealed off from or prevented from entering the inner chamber  48  of the exhaust gas selector valve  2  and flowing out the common outlet passage  16 . 
       FIG. 3  shows the exhaust gas selector valve  2  in a central position in which any exhaust gas from the first inlet passage  14  or the second inlet passage  30  is restricted from exiting the common outlet  16 . The actuator  10  actuates the shaft  12  to a central position in which the spring  22  biases the first valve face  17  of the first valve poppet  20  to seat against the first valve seat  26  and the second valve face  23  of the second valve poppet  18  to seat against the second valve seat  24 , restricting the flow of gas through the common outlet  16 . Exhaust gas that has passed through the EGR cooler  7  and into the first inlet passage  14  enters the pressure passage  19  in the first valve poppet  20  to aid in maintaining the seats of the valve poppets  20 ,  18  on the first valve seat  26  and the second valve seat  24  by reducing pressure biasing forces acting on the valve poppets  18 ,  20 . 
       FIG. 4  shows the exhaust gas selector valve  2  in a first position in which the second valve face  23  of the second valve poppet  18  contacts the second valve seat  24 , restricting any gas from the exhaust manifold  6  and from the second inlet passage  30  from entering the exhaust gas selector valve  2 . To move towards the first position, the actuator  10  actuates the shaft  12  towards the second inlet passage  30 . The movement of the shaft  12  towards the second inlet passage  30  actuates the actuating member or shoulder of the shaft  15  to actuate the first valve poppet  20 , moving the first valve poppet  20  towards the second valve poppet  18 . The movement of the first valve poppet  20  towards the second valve poppet  18  compresses the spring  22  between the first and second valve poppets  20 ,  18 . With the second valve face  23  of the second valve poppet  18  seating on the second valve seat  24 , exhaust gas that has passed through the EGR cooler  7  and into the first inlet passage  14  passes through the first valve seat  26  of exhaust gas selector valve  2  to the inner chamber  48  of the exhaust gas selector valve  2  and out the common outlet  16  leading to the intake manifold  5 . Exhaust gas that has passed through the EGR cooler  7  and into the first inlet passage  14  enters the pressure passage  19  in the first valve poppet  20  to aid in maintaining the seat of the second valve poppet  18  on the second valve seat  24  by reducing pressure biasing forces acting on the valve poppets  18 ,  20 . 
       FIG. 5  shows the exhaust gas selector valve  2  in a second position in which the first valve face  17  of the first valve poppet  20  contacts the first valve seat  26 , restricting any exhaust gas that has passed through the EGR cooler  7  and into the first inlet passage  14  from exiting the exhaust gas selector valve  2  through the common outlet  16 . To move towards the second position, the actuator  10  actuates the shaft  12  towards the first inlet passage  14 . The movement of the shaft  12  towards the first inlet passage  14  actuates the actuating member  13  to actuate the second valve poppet  18 , moving the second valve poppet  18  towards the first valve poppet  20 . The movement of the second valve poppet  18  towards the first valve poppet  20  compresses spring  22  between the first and second valve poppets  20 ,  18 . With the first valve face  17  of the first valve poppet  20  seated on the first valve seat  26 , hot exhaust gas, or gas straight from the exhaust manifold  6  from the second inlet passage  30  passes into the inner chamber  48  of the exhaust gas selector valve  2  and out the common outlet  16  leading to the intake manifold  5 . Exhaust gas that has passed through the EGR cooler  7  enters the pressure passage  19  in the first valve poppet  20  to aid in maintaining the seating of the first valve poppet  20  on the first valve seat  26  by reducing pressure biasing forces acting on the poppets  18 ,  20 . 
     In an alternate embodiment, the input of the first inlet passage  14  and the input of the second inlet passage  30  may be switched, so that the input of the first inlet passage  14  would be exhaust gas directly from the exhaust manifold  6  and the input of the second inlet passage  30  would be exhaust gas that has passed through the EGR cooler  7  and venturi  8 . 
     In another alternate embodiment, the selector valve has an inlet passage  64  and two outlet passages  60 ,  62 , with a first outlet passage  60  from a chamber  63  defined within the valve housing  44  between a plug  42  and the first valve seat of the exhaust gas selector valve  2  and a second outlet passage  62  from the inner chamber  48  of the exhaust gas selector valve  2 . The exhaust gas selector valve  2  would be mounted upstream of the EGR cooler  7  and venturi  8  as shown in  FIG. 7 . Exhaust gas from the exhaust manifold  6  can be directed to the inlet of the EGR cooler  7  from the first outlet passage  60  or directly to the intake manifold  5  from the second outlet passage  62 . 
     When the selector valve  2  is in a central position, gas from the inlet passage  64  would be restricted from exiting the valve through the first outlet passage  60  and the second outlet passage  62 . The actuator  10  actuates the shaft  12  to a central position in which the spring  22  biases the first valve face  17  of the first valve poppet  20  to seat against the first valve seat  26  and the second valve face  23  of the second valve poppet  18  to seat against the second valve seat  24 , restricting the flow of gas from the inlet passage  64  through the two outlet passages  60 ,  62 . Gas from the intake manifold  5  from outlet passage  60  enters the pressure passage  19  in the first valve poppet  20  and may aid in maintaining the seats of the valve poppets  20 ,  18  on the first valve seat  26  and the second valve seat  24  by reducing pressure biasing forces acting on the valve poppets  18 ,  20 . 
     When the selector valve  2  is in a first position in which the second valve face  23  of the second valve poppet  18  contacts the second valve seat  24 , as shown in  FIG. 7 , any gas from inlet passage  64  is restricted from exiting the second outlet passage  62  and instead exits the valve through the first valve seat  26  and from the first outlet passage  60 . To move towards the first position, the actuator  10  actuates the shaft  12  towards the second outlet passage  62 . The movement of the shaft  12  towards the second outlet passage  62  actuates the actuating member or shoulder of the shaft  15  to actuate the first valve poppet  20 , moving the first valve poppet  20  towards the second valve poppet  18 . The movement of the first valve poppet  20  towards the second valve poppet  18  compresses the spring  22  between the first and second valve poppets  20 ,  18 . With the second valve face  23  of the second valve poppet  18  seating on the second valve seat  24 , exhaust gas from the exhaust gas manifold  6  and into the inlet passage  64  passes through the first valve seat  26  of exhaust gas selector valve  2  and out the first outlet  60  passage leading to the intake manifold  5 . Exhaust gas from the inlet passage  64  also enters the pressure passage  19  in the first valve poppet  20  to aid in maintaining the seat of the second valve poppet  18  on the second valve seat  24  by reducing pressure biasing forces acting on the valve poppets  18 ,  20 . 
     When the selector valve  2  in a second position in which the first valve face  17  of the first valve poppet  20  contacts the first valve seat  26 , any gas from inlet passage  64  is restricted from exiting the first outlet passage  60  and instead exits through the valve through the second valve seat  24  and from the second outlet  62 . To move towards the second position, the actuator  10  actuates the shaft  12  towards the first outlet passage  60 . The movement of the shaft  12  towards the first outlet passage  60  actuates the actuating member  13  to actuate the second valve poppet  18 , moving the second valve poppet  18  towards the first valve poppet  20 . The movement of the second valve poppet  18  towards the first valve poppet  20  compresses spring  22  between the first and second valve poppets  20 ,  18 . With the first valve face  17  of the first valve poppet  20  seated on the first valve seat  26 , hot exhaust gas, or gas straight from the exhaust manifold  6  from the inlet passage  64  passes into the inner chamber  48  of the exhaust gas selector valve  2  and out the second outlet passage  62  leading to the intake manifold  5 . Exhaust gas from the inlet passage  64  also enters the pressure passage  19  in the first valve poppet  20  to aid in maintaining the seat of the second valve poppet  18  on the second valve seat  24  by reducing pressure biasing forces acting on the valve poppets  18 ,  20 . 
     It should be noted that while the valve is discussed in terms of selecting a gas, a person skilled in the art would be able to use the valve with a fluid. 
     Accordingly, it is to be understood that the embodiments of the invention herein described are merely illustrative of the application of the principles of the invention. Reference herein to details of the illustrated embodiments is not intended to limit the scope of the claims, which themselves recite those features regarded as essential to the invention.