Abstract:
An engine valve assembly is provided with a valve housing configured to promote easy fastening and removal of the valve assembly from an engine cover. The housing has a first wall and a side wall that extends therefrom to partially define an interior cavity with a cavity opening opposite the first wall. In some embodiments, the first wall has a generally teardrop-shaped surface. The first wall has a valve opening and a fastener opening that is spaced from and aligned with the valve opening along the first wall. A valve body is supported by the valve housing at least partially within the interior cavity, and may be press-fit therein. The valve housing mounts to the engine cover with the fastener inserted through the fastener opening to extend through the interior cavity and fasten to the engine cover, with the valve body extending into the engine cover.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Application 61/083,663, filed Jul. 25, 2008, which is hereby incorporated by reference in its entirety. 
     
    
     TECHNICAL FIELD 
       [0002]    The invention relates to an engine valve assembly mountable to an engine cover. 
       BACKGROUND OF THE INVENTION 
       [0003]    An electro-hydraulic system of valves typically controls inlet and exhaust from engine cylinders, as well as the amount of valve lift, in a modern automotive engine. Multiple valves are typically mounted to an engine cam cover. The cover is often of complex topography and must accommodate a variety of other components. An electro-hydraulic valve for an engine that fastens to the cam cover without interference from other components and in an ergonomic manner is desired. 
       SUMMARY OF THE INVENTION 
       [0004]    An engine valve assembly is provided with a valve housing, also referred to as a can or cover, that is configured to promote easy access to a fastener used for fastening and removing the valve assembly from an engine cover. The valve assembly may be a solenoid-type oil control valve assembly or other type of engine valve that mounts to an engine cover, and the engine cover may be a cam cover, or any portion of an engine block. The can has a first wall and a side wall that extends therefrom to partially define an interior cavity with a cavity opening opposite the first wall. In some embodiments, the first wall has a generally teardrop-shaped surface, as described in detail herein. The first wall has a valve opening as well as a fastener opening that is spaced from and aligned with the valve opening along the first wall. A valve body is supported by the valve housing at least partially within the interior cavity, and may be press-fit therein, in alignment with the valve opening. The valve housing is configured to mount to the engine cover with the fastener inserted through the fastener opening to extend through the interior cavity and fasten to the engine cover, with the valve body extending into the engine cover. Separation of the fastener opening from the face of the engine cover by the side wall makes the fastener more accessible for insertion and removal, especially if the engine cover has unusual surface geometry or adjacent components that would make access to a fastener opening closer to the engine cover surface more difficult. Cans that have a teardrop-shaped surface may more easily fit in available packaging space on the engine cover due to the tapered nature of the teardrop shape. 
         [0005]    Some embodiments of the can have an opening in the sidewall, also referred to as a window, through which an electrical connector connects with a valve coil and extends for easy access with a mating connector. The window may be offered in different positions on the sidewall for different embodiments, depending on specific application needs. Different electrical connectors may be connected on cans with like windows, as the window may permit connectors of various orientations. 
         [0006]    The above features and advantages and other features and advantages of the present invention are readily apparent from the following detailed description of the best modes for carrying out the invention when taken in connection with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]      FIG. 1A  is a schematic perspective illustration of a first embodiment of an engine oil control valve assembly having a first embodiment of a valve can; 
           [0008]      FIG. 1B  is a schematic top view of the valve can of  FIG. 1A ; 
           [0009]      FIG. 2  is a schematic cross-sectional illustration of the valve assembly with valve can of  FIG. 1 , taken at the lines  2 - 2  of  FIG. 1A ; 
           [0010]      FIG. 3  is a schematic cross-sectional illustration of the valve assembly with valve can of  FIG. 1A , taken at the lines  3 - 3  of  FIG. 1A  and shown with a fastener mounting the valve to an engine cam cover; 
           [0011]      FIG. 4  is a schematic perspective illustration of an alternative valve can for use with the valve body of  FIGS. 1A-3 , including a window for electrical connector access; 
           [0012]      FIG. 5  is schematic perspective illustration of a second embodiment of an engine oil control valve assembly with the can of  FIG. 4  and a first embodiment of an electrical connector extending laterally through the window; 
           [0013]      FIG. 6  is a schematic perspective illustration of a third embodiment of an engine oil control valve assembly with the can of  FIG. 4  and a second embodiment of an electrical connector extending at a skewed angle through the window; 
           [0014]      FIG. 7  is a schematic perspective illustration of a fourth embodiment of an engine oil control valve assembly with the can of  FIG. 4  and a third embodiment of an electrical connector extending through the window and vertically; 
           [0015]      FIG. 8  is a schematic perspective illustration of a fifth embodiment of an engine oil control valve assembly with a third embodiment of a can and a fourth embodiment of an electrical connector extending through the window and vertically; 
           [0016]      FIG. 9  is a schematic perspective illustration of a sixth embodiment of an engine oil control valve assembly with a fourth embodiment of a can and a fifth embodiment of an electrical connector extending through the window and vertically; and 
           [0017]      FIG. 10  is a schematic perspective illustration in fragmentary view of the valve assembly of  FIG. 5  mounted to a second embodiment of an engine cam cover. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0018]    Referring to the drawings, wherein like reference numbers refer to like components,  FIG. 1A  shows an engine oil control valve assembly  10  including a valve housing  12 , also referred to as a can or cap, with a first wall  14  having a generally teardrop-shaped face  16 . A valve body  17  extends from the can  12 . The valve can  12  includes a side wall  18  extending from a periphery  20  of the first wall  14 , generally perpendicularly to the face  16 . The valve body  17  is press-fit into an interior cavity  19  formed by the face  16  and side wall  18  (shown in  FIG. 2 ), through a cavity opening at terminal end  21  of the side wall  18 . The periphery  20  is shown most clearly in  FIG. 1B . A pole piece cover  22  shown in  FIG. 1A  is removed in  FIG. 1B  to reveal a valve opening  24  in the first wall  14 . A fastener opening  26  is displaced laterally from the valve opening  24  along the face  16 . 
         [0019]    Referring to  FIG. 1B , the teardrop-shaped face  16  is determined by the periphery  20 , which has a first portion  28  extending from point A to point B that is characterized by a first radius R 1  centered at a center C 1  of the valve opening  24 . The periphery  20  also has a second portion  30  extending from point C to point D that is characterized by a second radius R 2  centered at a center C 2  of the fastener opening  26 . A third portion  32  of the periphery connects the first portion  28  with the second portion  30 , as does an opposite fourth portion  34 . 
         [0020]    Although the teardrop-shaped face  16  is established by the periphery  20  described above, other teardrop-shaped faces as well as faces that are not teardrop-shaped and are established by different peripheries, are within the scope of the claimed invention. In general, a “teardrop-shaped” face is a generally planar face with a periphery that generally tapers from a larger rounded portion to a smaller rounded portion. 
         [0021]    As illustrated in  FIGS. 2 and 3  and as further described below, the can  12  of the engine oil control valve assembly  10  enables ease in fastening to an engine cover, and more specifically, a cam cover  37  (shown in  FIG. 3 ) via a threaded fastener  38 . As used herein, an engine cover may be a cam cover. Referring to  FIG. 2 , the engine oil control valve assembly  10  includes an electrical coil  40  surrounded by a coil support portion  42  (also referred to as a bobbin) of the valve body  17  and encapsulated in a coil cover  43 . The valve body  17  defines an armature chamber  44  in which a pole piece  46  is press-fit. An armature  48  is movable in the armature chamber  44  in response to energizing of the coil  40 . A main spring  49  biases the armature  48  away from the pole piece. A flux collector  50  (also referred to as a flux bracket) is supported adjacent the coil  40  and armature  48  by a base portion  51  of the valve body  17 . Electrical wiring for energizing of the coil  40  may be connected with the coil  40  through wiring openings  41 , shown in  FIGS. 1A and 1B . Alternatively, an electrical connector may be mounted in a fixed position to the side wall  18 , accessing the coil  40  through the side wall  18 . 
         [0022]    The pole piece  46 , valve can  12 , coil  40 , armature  48  and flux collector  50  form an electromagnet. Lines of flux are created in an air gap between the pole piece  46  and the armature  48  when the coil  40  is energized by an electric source (such as a battery, not shown). The armature  48  moves in response to the flux. 
         [0023]    The valve body  17  includes an extension portion  52  open to receive inlet flow from an oil pump (not shown) at a supply pressure, indicated as arrow E. The oil control valve assembly  10  is a normally closed valve, with a poppet valve  54  movable along a rod  56  fit to the armature  48 . A regulator spring  55  biases the poppet valve  54  to a closed position. The poppet valve  54  is thus biased to close an exhaust flow path  57 , with exhaust flow indicated as arrow F, when the coil  40  is not energized. This prevents exhaust venting of oil in control port  58  that flows at a control pressure to an engine valve latching mechanism (not shown). When the coil  40  is not energized and the control pressure is too high, the biasing force of the spring  55  will be overcome, lifting the poppet valve  54 , to allow oil in the control port  58  to vent through channel  62  to exhaust flow path  57 , until control pressure is adequately decreased. Alternatively, when control pressure is too low and the coil  40  is not energized, the biasing force of main spring  49  will be overcome by force of fluid at supply pressure, lifting the armature  48  and rod  56  and allowing the ball  60  to move upward so that fluid at supply pressure E flows to the control port  58  until control pressure is adequately increased. When the coil is energized, the armature  48  and rod  56  move upward, permitting fluid flow at supply pressure E to control port  58 . 
         [0024]    The base portion  51 , coil support portion  42 , extension portion  52 , and can  12  may be made integral or made unitary with one another by casting, molding, or other processes. 
         [0025]    A tubular support member  64  is connected to the can  12  by a press-fit, welding, bonding or otherwise at the fastener opening  26 . The tubular support member  64  is a material sufficient to bear torque loading when the threaded fastener  38  is driven through the support member  64  to a threaded opening  66  (see  FIG. 3 ) in the cam cover  37 . For example, the can  12  and the support member  64  may both be 1010 steel. Although not shown in  FIGS. 2 and 3 , the support member  64  may be thicker than the face  16  and side wall  18  of the can  12  if considered necessary to withstand the expected torque loading. A plug insert  68  surrounds the support member  64  to partially fill the opening of the can  12  at the terminal end of the side wall  18  between the tubular support member  64  and the side wall  18 . 
         [0026]    Referring to  FIG. 3 , with the oil control valve assembly  10  mounted to the cam cover  37  by threaded fastener  38 , the valve body  17  extends into a valve bore  70  in the cam cover  38 . Seals  72 A,  72 B and  72 C seal the valve body  17  to the bore  70  and the can  12  encloses the bore  70  at the cam cover surface  74 . 
         [0027]    A head  76  of the fastener  38  rests on the face  16  of the can  12  when the fastener  38  is adequately tightened to secure the valve assembly  10  to the cam cover  37 . The pole piece cover  22  is removed in  FIG. 3 , but fits adjacent the secured fastener head  76 , as is apparent from  FIG. 2 . 
         [0028]    In various engine embodiments, the cam cover  37  in the vicinity of the valve bore  70  may be at a severe angle to horizontal and may also have many additional surrounding components that limit access to the area above the valve bore  70  and threaded opening  66 . Especially in such situations, because the fastener head  76  rests on the face  16 , elevated from the cam cover surface  74  by the side wall  18 , the fastener opening  26  is more accessible to tools used to torque the fastener  38  than, for example, a fastener opening much closer to the surface  74 . Additionally, the teardrop-shape of the face  16  allows the fastener  38  and threaded opening  66  to align with one another in a tight packaging space, with close surrounding cam cover surface geometry and/or surrounding components. 
         [0029]    Referring to  FIG. 4 , another embodiment of a valve housing or can  12 A is shown that has an opening, referred to herein as a window  78  in the sidewall  18 A. All other features of the can  12 A are identical to those of can  12  of  FIG. 1 , and are referred to with like reference numbers. The window  78  allows an electrical connector connected with the coil of the valve body to extend from the can  12 A in a variety of possible directions, allowing connection with a mating connector in a manner that is not impeded by surrounding components or surface geometry of the cam cover. For example,  FIG. 5  shows oil control valve assembly  10 A, alike in every aspect to oil control valve assembly  10  of  FIG. 1  with the exception of can  12 A. The window  78  allows connector  80  to attach to valve body  17  in a direction substantially perpendicular to the plane of window  78 . The coil cover  43  is visible through window  78 . 
         [0030]      FIG. 6  shows oil control valve assembly  10 B with can  12 A, valve body  17  and connector  80 A. Oil control valve assembly  10 B is alike in every aspect to oil control valve assembly  10 A, with the exception of the positioning of connector  80 A. The window  78  allows the connector  80 A to extend at an angle G from a line perpendicular to the plane of the window  78 . Thus, a connector that mates with connector  80 A is installed non-perpendicularly to the window  78 . 
         [0031]      FIG. 7  shows valve assembly  10 C with can  12 A, valve body  17  and connector  80 B. Oil control valve assembly  10 C is alike in every aspect to oil control valve assemblies  10 A and  10 B, with the exception of the positioning of connector  80 B. Connector  80 B connects with the coil  40  shown in  FIG. 2  through the window  78  and extends beyond the face  16  to allow connection to a mating connector in a direction substantially parallel with the valve opening  24 . 
         [0032]      FIG. 8  shows oil control valve assembly  10 D with can  12 B, valve body  17  and connector  80 C. Oil control valve assembly  10 D is alike in every aspect to oil control valve assembly  10 A, with the exception of window  78 A being in a different position on sidewall  18 B to allow the positioning of connector  80 C, as shown, and window  78 A extending into a portion of face  16 A. 
         [0033]      FIG. 9  shows oil control valve assembly  10 E with a can  12 C, valve body  17  and connector  80 D positioned in connection with the coil  40  of  FIG. 2  through window  78 B of side wall  18 C, with connector  80 D in a different orientation than connector  80 C. A larger portion of window  78 B extends into face  16 B so that a portion of connector  80 D rests above face  16 B. Connector  80 D is positioned for connection with a mating connector in a direction substantially perpendicular to the valve opening  24 . 
         [0034]      FIG. 10  shows oil control valve assembly  10 A of  FIG. 5  mounted to cam cover  37 A by fastener  38 . Fastener head  76  is accessible for insertion and removal of the fastener  38  regardless of the limited access space due to uneven surface geometry of face  74  and surrounding components  82 ,  84  and dipstick  86 . Elevation of the fastener head  76  above the surface  74 A by sidewall  18  promotes easy access. As in  FIG. 5 , the connector  80  extends through window  78  in a direction substantially perpendicular to the fastener  38 . Thus, the fastener  76  is inserted in a different direction than a direction by which the mating connector is connected with terminals  88  of connector  80 . 
         [0035]    While the best modes for carrying out the invention have been described in detail, those familiar with the art to which this invention relates will recognize various alternative designs and embodiments for practicing the invention within the scope of the appended claims.