Abstract:
A valve arrangement having a valve body with an inlet passage and an outlet passage. A valve seat is disposed in the valve body and forms an aperture positioned in the path of fluid flow between the inlet and outlet passages. A shaft member is disposed within the valve body and has a flow control member connected to the end of the shaft. The flow control member has a valve portion for operably engaging the valve seat and a valve extension portion that extends from the valve portion and circumscribes the shaft in order to shield the shaft from being exposed to contaminants. The valve portion and valve extension portion are integrally formed into a one-piece member thus eliminating an additional component in the valve design.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates to a one-piece valve arrangement and method of assembly of the valve arrangement in order to maintain proper alignment of the valve member with the valve seat during assembly.  
       BACKGROUND OF THE INVENTION  
       [0002]     Poppet style valves are well known and used in controlling the flow of fluids and especially gasses through a valve body. For example, the recirculation of a portion of the exhaust stream of an internal combustion engine into the intake manifold can be accomplished using a poppet style exhaust gas recirculation (EGR) valve. One obstacle with using valves of any type in an EGR application is that the valve member will almost certainly be exposed to moisture laden corrosive vapor that can adhere to and cause coking on the valve shaft. Sometimes the coking materials can enter into the actuator housing by seeping through the bushing between the valve shaft and actuator as the valve shaft moves in an axial direction. This can cause unwanted corrosion of the actuator.  
         [0003]     In order to prevent the exposure of the valve shaft to contaminants some valves have been designed to incorporate certain anti-contamination features that will direct the corrosive gasses away from the valve shaft during valve operation. The use of anti-contamination features increases the number of parts that must be arranged during assembly. Additionally, the use of anti-contamination features can also effect the alignment of the valve member with regard to the valve seat since the use of such items as shaft shields, scrapers and other features make it more difficult to align the valve member with the valve seat during assembly.  
       SUMMARY OF THE INVENTION  
       [0004]     The present invention relates to a valve arrangement having a valve body with an inlet passage and an outlet passage. A valve seat is disposed in the valve body and forms an aperture positioned in the path of fluid flow between the inlet and outlet passages. A shaft member is disposed within the valve body and has a flow control member connected to the end of the shaft. The flow control member has a valve portion for operably engaging the valve seat and a valve extension portion that extends from the valve portion and circumscribes the shaft in order to shield the shaft from being exposed to contaminants. The valve portion and valve extension portion are integrally formed into a one-piece member thus eliminating an additional component in the valve design.  
         [0005]     The present invention also includes a method of assembling a valve while maintaining alignment of the valve member with respect to the valve seat during assembly. The valve member has a housing with an inlet port and an outlet port. A valve seat is arranged in the housing in the path of fluid flow between the inlet and outlet ports. A flow control member having a valve portion has an axial aperture formed through the valve member for receiving an end of a valve shaft. The method of aligning includes placing the flow control member against the valve seat, sliding one end of the valve shaft into the aperture of the flow control member, adjusting the position of the valve shaft to a predetermined position in order to allow proper valve function and fixing the valve shaft to the flow control member once proper alignment has been set.  
         [0006]     Further areas of applicability of the present invention will become apparent from the detailed description provided hereafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0007]     The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:  
         [0008]      FIG. 1  is a cross-sectional plan view of the valve housing with the one-piece flow control member inserted and aligned with the valve seat and having the valve shaft located outside of the valve body prior to insertion;  
         [0009]      FIG. 2  is a cross-sectional plan view of the flow control member positioned in alignment with the valve seat having the valve shaft connected to the flow control member after alignment;  
         [0010]      FIG. 3  is a close up cross-sectional plan view of the flow control member seated on the valve seat with the end of the valve shaft inserted through the aperture of the flow control member during alignment; and  
         [0011]      FIG. 4  is a cross-sectional plan view of an alternate embodiment of the invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0012]     The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.  
         [0013]      FIGS. 1-3  show a valve arrangement  10  that incorporates a one piece flow control member  22  and depicts a method of aligning the flow control member  22  during assembly of the valve arrangement  10 . The valve arrangement  10  includes a valve body  12  having an inlet port  14  and an outlet port  16 . The valve body  12  defines the path of fluid flow between the inlet port  14  and the outlet port  16 . The fluid flowing through the valve body  12  can be any type of fluid medium where a valve incorporating a flow control member  22  can be used. This particular embodiment of the invention depicts a valve body  12  that is part of an exhaust gas recirculation (EGR) valve member and the fluid medium flowing through the valve body  12  is exhaust gas from the engine exhaust manifold that is recirculated back to the intake manifold of the engine. A valve seat  18  having an aperture  20  is contained within the valve body  12  and is positioned in the path of fluid flow between the inlet port  14  and outlet port  16 . The valve seat  18  can be a separate piece that is press fit into the valve body  12  or it may be cast or integrally formed within the valve body  12 .  
         [0014]     The flow control member  22  is configured to selectively engage with the valve seat  18  in order to seal off the aperture  20  and block the flow of fluid between the inlet port  14  and outlet port  16 . The flow control member  22  is an integrally formed one piece member having a valve portion  24 , that is a surface configured to mate with and seal against the valve seat  18 . The flow control member  22  also has a valve extension  26  that extends from the valve portion  24  and is defined as the portion of the flow control member  22  that extends beyond that which is necessary to facilitate the opening and closing of the valve seat  18 .  
         [0015]     The valve extension portion  26  is shown in the drawings as being an annular wall that circumvents a portion of a valve shaft  30 . However, the valve extension portion  26  does not necessarily have to be an annular wall that circumvents a portion or the valve shaft  30 ; rather it can take many forms and does not have to extend a great distance from the valve portion  24 . The valve extension portion  24  can provide many benefits such as coking and or flow deflection. In the present embodiment of the invention the valve extension portion  26  functions to protect the valve shaft  30  from coming into direct contact with the fluid medium moving through the aperture  20  of the valve seat  18  from the inlet port  14 . By preventing contact- of fluid medium with the valve shaft  30  there is a significant reduction in the occurrence of coke formation on the valve shaft  30 .  
         [0016]     The flow control member  22  also has a stem  28  formed generally about the longitudinal axis of the valve shaft  30 . The stem  28  shown in  FIGS. 1-2  have an open end, while  FIG. 3  is slightly different in that the stem  28  has a closed end  35  and forms a blind hole. The valve shaft  30  has a moveable end  32  that is configured to slide into the stem  28 . A radial groove  34  is formed on the surface of the valve shaft  30  near the moveable end  32 . The radial groove  34  is also configured to slide within the stem  28 . The valve shaft  30  is then connected to the flow control member  22  by forming a crimp  38  in the stem  28 , so that the stem  28  has a crimp  38  formed at the location of the radial groove  34  on the valve shaft  30 . Once the crimp  38  has been formed the flow control member  22  will move longitudinally with the sliding movement of the valve shaft  30  to open and close aperture  20  of the valve seat  18 .  
         [0017]      FIGS. 1-3  depict a method for aligning the flow control member  22  during assembly of the valve arrangement  10  so that the valve portion  24  will properly seat against the valve seat  18  to ensure proper valve operation.  FIG. 1  depicts the first step of placing the flow control member  22  in position against the valve seat  18 . While  FIG. 1  depicts the flow control member  22  being placed against the valve seat  18  it is within the scope of this invention for the flow control member  22  to be placed at any predetermined position relative to the valve seat. The flow control member  22  is positioned so that the stem  28  extends through the aperture  20  of the valve seat  18 . The moveable end  32  of the valve shaft  30  is then slid into position so that the moveable end  32  enters the stem  28 .  FIG. 2  shows the valve shaft being placed in position. Aligning the valve shaft  30  also involves inserting bushing  40  to the proper depth in the valve body  12 . Achieving proper alignment of the valve shaft and bushing  40  eliminates the need to use shims or other spatial compensating components. Once alignment has been achieved the stem  28  is crimped  38  to connect the flow control member  22  to the valve shaft  30 .  
         [0018]      FIG. 3  shows the point of connection between the shield valve  22  and the valve shaft  30 .  FIG. 1  as depicted is slightly different from  FIG. 2  in that the stem  28  has a closed end or blind hole that the valve shaft  30  slides into. This will ensure that there can be no leakage through the valve seat  18  by way of the connection point between the stem  28  and valve shaft  30 . The crimp  38  that hold the flow control member  22  to the valve shaft  30  is formed at the radial groove  34 . It is also within the scope of this invention to fasten the flow control member  22  to the valve shaft  30  by a means other than the crimp  38 . For example, adhesives, soldering or laser welding can be used to connect the valve shaft  30  to the flow control member  22 .  FIG. 3  shows a close-up view of the radial groove  34  at the formation of the crimp  38 . Knurled portions  36  on the moveable end  32  of the valve shaft  30  are placed adjacent the radial groove  34 . The knurled portions  36  function during the step of sliding the valve shaft  30  into the stem  28  by preventing unwanted movement of the valve shaft  30  during assembly.  
         [0019]     The flow control member  22  is not necessarily placed relative to the valve seat, rather the predetermined position can be in relation to a specific flow position, or a full open stop, or in relation to a valve mounting surface feature. The reason for this is that the flow control member  22 , valve shaft  30  and a bushing  40  may be supplied independent from the valve body  12 . For example, the valve body  12  may be integrally formed as part of another component such as a turbocharger housing and an engine intake manifold. The flow control member  22  valve stem  30  and bushing  40  may be connected to an actuator (not shown) that is fastened to the valve body  12 . It is possible to pre-configure the flow control member  22  based on the mounting surface between the valve body  12  and the actuator (not shown) that controls the position of the flow control member  22 .  
         [0020]      FIG. 4  depicts an alternate embodiment of a valve arrangement  100 . This particular embodiment of the invention has a flow control member  102  that has a slightly modified configuration. The flow control member  102  has a stem  104  that does not extend into the aperture  20  of the valve seat  18 . The valve seat  18  is closed by an annular shoulder  106  that rests against the surface of the valve seat  18 . The stem  104  is used to connect the flow control member  102  with the valve shaft  30  in a manner similar to the embodiment of the invention described in  FIGS. 1-3 . That is the end of the valve shaft  30  slides into the stem  104  and the crimp  34  is formed in between the stem  104  and the valve shaft  30 . The crimp  34  connects the flow control member  102  with the valve shaft  30  so that the flow control member  102  moves with the valve shaft during operation of the valve arrangement  100 .  
         [0021]     The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.