Patent Abstract:
An electromagnetic hydraulic valve or solenoid having an electric plug, housing, magnetic coil, armature and armature pin, valve body and associated valve seat and valve plate and associated valve seat, the valve plate axially retained, but, freely floating laterally within the housing, such that the valve plate and valve plate seat is movable to align with the valve body and valve body seat.

Full Description:
The present invention relates to a solenoid valve, in particular, a valve plate for a solenoid valve. 
     BACKGROUND 
     Typically, solenoid valves are electromechanically operated valves having two main parts; the solenoid and the valve. The solenoid converts electro-magnetic energy into mechanical energy which, in turn, opens or closes the valve mechanically. Solenoid valves are used in a wide variety of applications, including in switchable valvetrains of internal combustion engines. Solenoid valves are disclosed in U.S. Pat. No. 7,137,411, and U.S. Pat. No. 6,367,434 wherein the solenoid valve comprises an electromagnet having a hollow cylindrical magnet housing, at least one coil winding and an armature, and a valve member having a hollow cylindrical valve housing for receiving a spool valve which is displaceable relative to the valve housing by the armature of the electromagnet. 
     So called “fast switching solenoids” operate by the same principle as solenoid valves generally. PCT application PCT/EP2012/062080 describes such a fast switching solenoid, comprising a magnetic coil surrounding an armature and magnetic core, the armature connected to a armature pin, extending through the magnetic core and attached to a valve body. A perforated housing member surrounds the valve assembly, the assembly comprising a valve spring, spring seat, valve body, valve plate on which the valve body seats and a spring retainer. 
     In fast switching solenoid valves, a seal can be used between the magnet core, valve body and the spring seat in order to ensure isolation between the high pressure chamber, around the periphery of the perforated housing, and middle pressure chamber, at the bottom of the valve, adjacent the spring retainer. Where misalignment occurs between the valve body and the valve plate in the housing, the seal can be compressed or permanently compacted during operation of the valve body during actuation. This seal may also contribute to increased friction of the system, depending on the temperature and pressure of the oil, negatively influencing switching performance of the valve. 
     The valve plate is typically pressed into the housing, requiring a tight tolerance between the valve plate and the housing and sorting of parts during assembly. 
     SUMMARY OF THE INVENTION 
     Certain terminology is used in the following description for convenience and descriptive purposes only, and is not intended to be limiting to the scope of the claims. The terminology includes the words specifically noted, derivatives thereof and words of similar import. 
     The present invention relates to a fast switching solenoid valve, and more particularly, to a free floating valve plate for a solenoid valve. Solenoid valves have a electromagnetic portion and a valve portion, the electromagnet having an electric plug contact, a housing, magnetic coil and armature. The valve portion having a pin associated with the armature, urging against a valve body, a valve plate and a perforate housing directing flow, as required. 
     The valve plate is axially retained within the housing, however, it is loosely fitted within the cylindrical portion of the housing, such that it self-aligns to the abutting valve body valve seat when the solenoid is actuated, correcting for any misalignments or tolerancing issues. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       The above mentioned and other features and advantages of the embodiments described herein, and the manner of attaining them, will become apparent and be better understood by reference to the following description of at least one example embodiment in conjunction with the accompanying drawings. A brief description of those drawings now follows. 
         FIG. 1  is a cross sectional view of a prior art solenoid valve. 
         FIG. 2  is a cross-sectional view of solenoid valve assembly according to one embodiment of the invention. 
         FIG. 3  is a cross sectional view of portion A of  FIG. 2 . 
         FIG. 4  is a cross sectional perspective view of valve body and valve plate of  FIG. 3 . 
         FIG. 5  is a perspective view of valve plate according to one embodiment of the invention. 
         FIG. 6  is a cross section view of solenoid valve assembly according to a second embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Identically labeled elements appearing in different ones of the figures refer to the same elements but may not be referenced in the description for all figures. The exemplification set out herein illustrates at least one embodiment, in at least one form, and such exemplification is not to be construed as limiting the scope of the claims in any manner. 
       FIG. 1  is a cross sectional view of prior art solenoid  100 , comprising electric plug  119 , cylindrical magnet housing or yoke ring  101  and valve housing  102  assembled together, forming housing  103 . Magnetic coil  104  is nested on an inner circumferential surface of yoke ring  101 , in turn surrounding armature  105 , armature spring  106 , armature sleeve  107 , capped on a upper surface by damper  108 . Armature  105  is a hollow cylindrical structure, abutting hollow cylindrical magnet core  110  on a lower surface of armature  105  and an upper surface of magnet core  110 . Armature pin  109  inserted through the middle of armature  105  and extending through magnet core  110 , and into a center hole  111  of valve body  112 . Valve plate spring  113  surrounds the outer circumferential surface of valve body  112 , and is seated at an upper periphery against spring seat  114 , and a lower periphery on valve plate  115 . Seal ring  118  is nested between an upper surface of spring seat  114 , and a lower conical surface of magnet core  110 , sealing the interior cavity  120  formed by the center holes of magnet core  110  and valve body  112 , from an outer cavity  121  formed by the outer surface of valve body  112  and the inner surface of valve housing  102 . An upper portion of valve spring  117  is inserted into the cupped portion  122  of valve body  112 , supported laterally by inner side walls  123  of valve body  112 , and supported on a lower portion by spring retainer  116 . 
     In prior art solenoid  100 , valve plate  115  is press fit into inner cavity  125  of valve housing  102 , abutting valve housing shoulder  124 . This press fit may be accomplished by one of several methods, including, but, not limited to, sorting valve plates  115  to accommodate a measured dimension of cavity  125 , and precise machining of both cavity  125  and plate  115  prior to press fitting of plate  115  into cavity  125 . To compensate for any misalignment and resulting leakage of valve body  112  onto valve plate  115 , or valve body  112  in magnet core  110 , ring seal  118  is inserted between magnet core  110 , spring seat  114  and valve body  112 . Where there is a relatively large misalignment between valve body  112  and valve plate  115 , seal  118  may be pinched or compressed on one end, causing increased wear and may decrease durability of seal  118 . 
       FIG. 2  is a cross sectional side view of solenoid  1  according to one embodiment of the invention, comprising electric plug  15 , cylindrical magnet housing or yoke ring  2  and valve housing  3  assembled together, forming housing  4 . Magnetic coil  5  is nested in an inner circumferential surface of yoke ring  2 , in turn surrounding armature  6 , armature spring  7 , armature sleeve  8 , capped on a upper surface by damper  9 . Armature  6  is a hollow cylindrical structure, abutting hollow cylindrical magnet core  10  on a lower surface of armature  6  and an upper surface of magnet core  10 . Armature pin  11  inserted through the center of armature  6  and extending through magnet core  10 , and into a center hole  12  of valve body  13 . Alternatively, armature pin  11  may only come into contact with valve body  13  at a top surface of valve body  13 , as shown in  FIG. 2 . Valve plate spring  14  surrounds the outer circumferential surface of valve body  13 , and is seated at an upper periphery against magnet core  10 , and at a lower periphery on valve plate retainer  19 . Valve plate retainer  19  is clipped or recessed into groove  21  in valve housing  3 , retaining free floating valve plate  20  between valve plate retainer  19  on an upper end and valve housing shoulder  22  on a lower end of valve plate  20 . An upper portion of valve spring  25  is inserted into cupped portion  26  of valve body  13 , supported laterally by inner side walls  27  of valve body  13 , and supported on a lower portion by spring retainer  28 . 
     In operation, in the embodiment shown, solenoid  1  is normally open, meaning that valve body  13  and valve plate  20  are separated by valve spring  25  acting to push valve body  13  upward. Alternatively, it is contemplated in the present invention that solenoid  1  can also be normally closed. In the activated mode shown in  FIG. 2 , magnetic coil  5  is energized, creating a magnetic field causing armature  6  and armature pin  11  to move downwards against valve body  13 , compressing valve spring  25  and seating convex valve body seat  29  against and into concave valve plate seat  30 , thus stopping fluid flow from the direction of spring retainer  28  and inner cavity  32  into outer cavity  31 . 
       FIG. 3  is an enlarged cross sectional view of portion A of  FIG. 2 . Yoke ring  2 , valve housing  3 , magnetic coil  5 , armature pin  11 , and magnet core  10  are as shown in  FIG. 2 . For clarity, valve plate spring  14  is not shown in order to show perforations  33  in valve housing  3 , which in a normally open state would be in fluid communication with fluid from spring retainer  28  and inner cavity  32 . In this embodiment, valve plate retainer  19  is inserted into valve plate retainer groove  21  in housing  3 , retaining free floating valve plate  20  between retainer  19  and shoulder  22 . It is also contemplated in the present invention that other retention mechanisms can be used, including, but not limited to, the use of valve plate spring  14  and shoulder  22  and a valve plate  20  and retainer  19  being formed as one component. 
     Seating of convex valve body seat  29  into concave valve plate seat  30  are better shown in  FIGS. 3 and 4 . In particular,  FIG. 4  is a cross sectional perspective view of valve body  13  and valve plate  20  only, including valve body cupper portion  26 , convex valve body seat  29  and concave valve plate seat  30 . 
       FIG. 5  is a perspective view of valve plate  20  according to one embodiment of the invention. Valve plate  20  is a hollow cylindrical shape having a raised disk shape  35 , forming a shoulder  36  on which can be seated valve plate retainer  19  (see  FIGS. 2 and 3 ) or valve plate spring  14 . toward the radial center of the raised disk  35  is concave valve plate seat  30 , to which convex valve body seat  29  can tightly abut and stop flow between the two surfaces. Circumferential outer surface  37  is dimensioned for any particular application such that plate  20  may freely float in valve housing  3  and remain seated on valve housing shoulder  22 . 
     As solenoid  1  is energized and valve body  13  is pushed downward by armature pin  11 , compressing valve spring  25  against spring retainer  28 , convex valve body seat  29  contacts at least a portion of valve plate seat  30 . As valve plate  20  moves freely laterally and is confined from movement upward or downward by shoulder  22  and retainer  19  and/or spring  14  so that no skewing occurs, valve plate  20  shifts laterally such that valve plate seat  30  aligns properly with valve body seat  29 , and the two surfaces are in continuous contact around their full circumference, this closing that fluid communication from inner cavity  32  to outer cavity  31  (see  FIG. 3 ). In this embodiment gap seal  40 , which is the gap between valve body  13  and magnet core  10 , which restricts flow from outer cavity  31  (see  FIG. 2 ), is elongated by lengthening magnet core extension  41 , providing further flow restriction. 
       FIG. 6  is a cross sectional view of solenoid  1 ′ according to a second embodiment of the invention. In this embodiment, the components similar to the embodiment described in  FIG. 2 , including valve body  13 ′, valve plate  20 , magnet core  10  and armature pin  11 . In this embodiment, piston ring seal  45  is inserted into groove  46  on valve body  13 ′, providing additional sealing from outer cavity  31 . Piston ring seal  45  contacts an inner surface  47  of magnet core extension  41 . Alternatively, seal  45  can be inserted into a groove (not shown) on surface  47  in magnet core extension  41 , and seal  45  may contact an outer surface of valve body  13 ′. 
     In the foregoing description, example embodiments are described. The specification and drawings are accordingly to be regarded in an illustrative rather than in a restrictive sense. It will, however, be evident that various modifications and changes may be made thereto, without departing from the broader spirit and scope of the present invention. 
     In addition, it should be understood that the figures illustrated in the attachments, which highlight the functionality and advantages of the example embodiments, are presented for example purposes only. The architecture or construction of example embodiments described herein is sufficiently flexible and configurable, such that it may be utilized (and navigated) in ways other than that shown in the accompanying figures. 
     Although example embodiments have been described herein, many additional modifications and variations would be apparent to those skilled in the art. It is therefore to be understood that this invention may be practiced otherwise than as specifically described. Thus, the present example embodiments should be considered in all respects as illustrative and not restrictive. 
     LIST OF REFERENCE SYMBOLS 
     
         
           1  Solenoid 
           2  Yoke Ring or Magnet Housing 
           3  Valve Housing 
           4  Housing 
           5  Magnetic Coil 
           6  Armature 
           7  Armature Spring 
           8  Armature Sleeve 
           9  Damper 
           10  Magnet Core 
           11  Armature Pin 
           12  Valve Body Center Hole 
           13  Valve Body 
           14  Valve Plate Spring 
           15  Electric Plug 
           19  Valve Plate Retainer 
           20  Valve Plate 
           21  Valve Plate Retainer Groove 
           22  Valve Housing Shoulder 
           25  Valve Spring 
           26  Valve Body Cupped Portion 
           27  Valve Body Inner Side Walls 
           28  Spring Retainer 
           29  Valve Body Seat 
           30  Valve Plate Seat 
           31  Outer Cavity 
           32  Inner Cavity 
           33  Perforations 
           35  Valve Plate Disk 
           36  Valve Plate Shoulder 
           37  Valve Plate Circumferential Outer Surface 
           40  Gap Seal 
           41  Magnet Core Extension 
           45  Piston Ring Seal 
           46  Groove 
           47  Magnet Core Inner Surface 
           100  Solenoid 
           101  Yoke Ring or Magnet Housing 
           102  Valve Housing 
           103  Housing 
           104  Magnet Coil 
           105  Armature 
           106  Armature Spring 
           107  Armature Sleeve 
           108  Damper 
           109  Armature Pin 
           110  Magnet Core 
           111  Valve Body Center Hole 
           112  Valve Body 
           113  Valve Plate Spring 
           114  Spring Seat 
           115  Valve Plate 
           116  Spring Retainer 
           117  Valve Spring 
           118  Seal Ring 
           119  Electric Plug 
           120  Interior Cavity 
           121  Outer Cavity 
           122  Valve Body Cupped Portion 
           123  Valve Body Inner Side Walls 
           124  Valve Housing Shoulder 
           125  Valve Housing Inner Cavity

Technology Classification (CPC): 5