Patent Publication Number: US-2018038540-A1

Title: Method for connection of plastic fittings in a coolant valve system

Description:
FIELD OF INVENTION 
     The present invention relates to a method of connecting plastic fittings together, and more particularly to thermal management valve modules used to direct coolant flows in motor vehicles, and particularly to vibration and leak-proof locking connections of plastic fittings used to couple the coolant flow lines to the valve body. 
     BACKGROUND 
     In automotive applications, there is a continued effort toward achieving energy efficiency. In connection with this effort, thermal management valve modules for controlling coolant flows are now being used more commonly in connection with motor vehicles in order to quickly reach and maintain optimum operating temperatures. One such thermal management valve module developed by the assignee of the present invention is disclosed in US2015/0027572, which is incorporated herein by reference as if fully set forth. This thermal management valve module has a plastic housing with multiple inlet and outlet connections that must be connected to plastic fittings that lead to and from the various coolant flow lines in the engine compartment of a motor vehicle, such as to and from the radiator, the vehicle passenger compartment heat exchanger, a battery pack, and/or the engine block cooling circuit. In the engine compartment, installation space is limited, and the connections must be able to provide a long term, reliable, leak-free connection in an exposed environment that is subject to high heat and vibration from the engine as well as corrosive external conditions. 
     One known prior art connection is shown in  FIG. 1 . Here the hose fitting  2  is connected to the housing  3  using a screw  4  or other threaded fastener, with an O-ring  5  contacting a gland  6  on the hose fitting  2  providing a seal. This design is less flexible, requires good tolerance control of the seal surfaces as well as more installation space for access to the screws, and has a high assembly cost. Further it is more prone to failure under the vibration and other conditions in a vehicle engine compartment. 
     It would be desirable to provide a simple solution for sealing and locking plastic fittings used in this and various other applications together in a secure and leak-proof manner with reduced cost and reduced installation space requirements. 
     SUMMARY 
     Briefly stated, a method for connection of fittings together is provided The method includes: (1) providing a first fitting part with an insertion end having an external circumferential groove, and a second fitting part with a wall defining an opening for receiving the insertion end of the first fitting part, the second fitting part including at least one circumferential slot located in the wall and facing the opening that is aligned with the external circumferential groove in an assembled position of the first and second fitting parts, and at least one flow hole that extends from a sealing space defined between the external circumferential groove and the at least one circumferential slot to an exterior of at least one of the first fitting part or the second fitting part; (2) inserting the insertion end of the first fitting part into the opening in the second fitting part to the assembled position; (3) injecting a curable liquid material through the at least one flow hole into the sealing space defined between the external circumferential groove of the first fitting part and the at least one slot in the second fitting part; and (4) curing the liquid material to form a sealed, form-locked connection between the first and second fitting parts. 
     In another aspect, the first fitting part has an annular cap that contacts a top of the wall of the second fitting part and acts as an outer barrier for the curable liquid material. Further, the insertion end of the first fitting part preferably has a clearance 0.08 inches or less with the opening in the assembled position to form an inner barrier for the curable liquid material. 
     In another aspect, a plurality of the flow holes are located on at least one of the first fitting part or the second fitting part spaced apart from one another about a periphery, and the method further comprises injecting the curable liquid material into each of the flow holes. 
     In another aspect, the method further includes engaging a filling nozzle with an outer opening of the at least one flow hole. Preferably, an inspection hole is also provided and can be located on the second fitting part spaced apart from the at least one flow hole. Here, the curable liquid material is injected until it flows out of the inspection hole, providing visual confirmation that the connection area is properly filled. 
     In one embodiment, the at least one slot comprises a plurality of circumferentially spaced apart slots. Alternatively, a single continuous slot can be provided. 
     In a preferred arrangement, the fittings are plastic and are part of a thermal management valve module used in connection with a motor vehicle. 
     Preferably, the curable liquid material is a resin or a polymer such as PPS, visible light/UV cure adhesives, or high temperature RTV. 
     In another aspect, a fitting connection for a thermal management valve module is provided and includes a first fitting part with an insertion end having an external circumferential groove, and a second fitting part with a wall defining an opening for receiving the insertion end of the first fitting part. The second fitting part includes at least one circumferential slot located in the wall and facing the opening that is aligned with the external circumferential groove in an assembled position of the first and second fitting parts. At least one flow hole extends from a sealing space defined between the external circumferential groove and the at least one circumferential slot to an exterior of at least one of the first fitting part or the second fitting part. A cured liquid material is located in and fills the at least one flow hole and the sealing space defined between the external circumferential groove of the first fitting part and the at least one slot in the second fitting part to form a sealed, form-locked connection between the first and second fitting parts. 
     Other aspects of the connection as discussed above are also useable in connection with the fitting connection for a thermal management valve module in order to provide a simple and secure fitting connection. The various aspects of the invention discussed herein can be used individually or in various combinations. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The foregoing Summary and the following detailed description will be better understood when read in conjunction with the appended drawings, which illustrate a preferred embodiment of the invention. In the drawings: 
         FIG. 1  is cross-sectional view of a fitting connection in accordance with the known prior art. 
         FIG. 2  is a detailed view of a first fitting part in accordance with an embodiment of the present fitting connection. 
         FIG. 3A  is a cross-sectional view of a first configuration of a second fitting part used with the present fitting connection. 
         FIG. 3B  is a cross-sectional view similar to  FIG. 3A  of a second configuration of a second fitting part used with the present fitting connection. 
         FIG. 4  is a cross-sectional view showing the present fitting connection with the first and second parts in the assembled position with an injectable curable liquid material connecting and sealing the first and second fitting parts together to form the fitting connection. 
         FIG. 5A  is a cross-sectional view of a further configuration of a second fitting part used with another embodiment of the present fitting connection. 
         FIG. 5B  is a cross-sectional view similar to  FIG. 5A  of an additional configuration of a second fitting part used with the present fitting connection. 
         FIG. 6  is a cross-sectional view showing another embodiment of a fitting connection with the first and second parts in the assembled position with an injectable curable liquid material connecting and sealing the first and second fitting parts together to form the fitting connection. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Certain terminology is used in the following description for convenience only and is not limiting. The words “front,” “rear,” “upper” and “lower” designate directions in the drawings to which reference is made. The words “inwardly” and “outwardly” refer to directions toward and away from the parts referenced in the drawings. A reference to a list of items that are cited as “at least one of a, b, or c” (where a, b, and c represent the items being listed) means any single one of the items a, b, or c, or combinations thereof. The terminology includes the words specifically noted above, derivatives thereof and words of similar import. 
     Referring now to  FIGS. 2, 3A, 3B, and 4 , a method for connection of two fittings together, preferably a first fitting part  12  and a second fitting part  20  for a thermal management valve module, will be explained in detail.  FIG. 2  shows the first fitting part  12  with an insertion end  14  having an external circumferential groove  16 . Preferably, the first fitting part  12  has an annular cap  18  that contacts a top wall of the second fitting part  20  as shown in  FIG. 4  in the assembled position of the first and second fitting parts  12 ,  20 . 
       FIG. 3A  shows a first configuration of a second fitting part  20  having a wall  22  defining an opening  24  for receiving the insertion end  14  of the first fitting part  12 . The second fitting part  20  includes at least one circumferential slot  26  in the wall  22  that faces the opening  24  and is aligned with the external circumferential groove  16  in the assembled position of the first and second fitting parts  12 ,  20  as shown in  FIG. 4 . At least one flow hole  28  extends from the at least one circumferential slot  26  to an exterior  30  of the second fitting part  20 , as shown in  FIG. 3A . In the configuration of  FIG. 3A , the second fitting part includes four circumferentially spaced apart slots  26 . However, this number could be varied. Each of the slots  26  preferably includes its own flow hole  28 . 
       FIG. 3B  shows a second configuration of the second fitting part  20 ′. The second configuration of the second fitting part  20 ′ is similar to the previously discussed arrangement of the second fitting part  20  except that a single continuously extending circumferential slot  26 ′ is located in the wall  22  and preferably includes a plurality of the flow holes  28  that are circumferentially spaced apart, as well as at least one inspection hole  38  that is located in the slot  26 ′ of the second fitting part  20 ′ spaced apart from the at least one flow hole  28 . 
     According to the method, the insertion end  14  and the first fitting part  12  is inserted into the opening  24  of the second fitting part  20 ,  20 ′ to the assembled position as shown in  FIG. 4 . Preferably, the annular cap  18  of the first fitting part  12  contacts a top of the wall  24  of the second fitting part and acts as an outer barrier  32  for the curable liquid material to be injected. Additionally, the insertion end  14  of the first fitting part preferably has a clearance of 0.08 inches or less with the opening  24  in the assembled position to form an inner barrier  34  for the curable liquid material to be injected. 
     As shown in  FIG. 4 , the curable liquid material  36  is injected through the at least one flow hole  28  into a space defined between the external circumferential groove  16  of the first fitting part  12  and the at least one slot  26 ,  26 ′ in the second fitting part  20 ,  20 ′. This is preferably accomplished by engaging a filling nozzle  40  with an outer opening of the at least one flow hole  28 . As shown in  FIG. 4 , a plurality of nozzles  40  can be provided that can be connected to some or all of the flow holes  28 . The curable liquid material can be injected into each of the flow holes via these filling nozzles  40 . However, as shown in connection with  FIG. 3B , an inspection hole  38  can also be provided on the second fitting part  20 ′ that is spaced apart from the at least one flow hole  28  and the curable liquid material  36  can be injected until it flows out of the inspection hole  38 . As shown in  FIG. 4 , the curable liquid material  36  cures to form a sealed, formed locked connection between the first and second fitting parts  12 ,  20 . 
     The curable liquid material  36  is preferably a resin or a polymer and is injectable in liquid form and fully fills the space formed by the circumferential groove  16  and the single continuous circumferential slot  26 ′, as shown in connection with the second fitting part  20 ′ in  FIG. 3B , or the plurality of the circumferentially spaced apart slots  26  in the second fitting part  20  as illustrated in  FIG. 3A . Various resins or polymers such as PPS, visible light/UV cure adhesives, and high temperature RTV sealing materials can be used as the curable liquid material  36 , and these materials preferably all cure at room temperature. One preferred material that can be used as the curable liquid material  36  is a high temperature RTV (room temperature vulcanizing) silicone. 
     In another aspect of the invention, a fitting connection  10  for a thermal management valve module is provided, as shown in  FIG. 4 . Here, the first fitting part  12  as described above is provided. The thermal management valve module includes a wall portion that forms the second fitting part  20 ,  20 ′, as described above. The cured liquid material  36  is located in and fills the at least one flow hole  28  and a space defined between the external circumferential groove  16  of the first fitting part  12  and the at least one slot  26  in the second fitting part  20 ,  20 ′ to form a sealed, formed-locked connection between the first and second fitting parts  10 ,  20 ,  20 ′. This fitting connection  10  is both secure against heavy vibration and leak proof. Further, it requires little installation space for assembly and can be made in situ in an engine compartment of a motor vehicle. 
     Referring to  FIGS. 5A, 5B, and 6 , another embodiment of the second fitting part  120 ,  120 ′, shown in two different configurations in  FIGS. 5A and 5   b , having a wall  122 ,  122 ′ defining an opening  124  for receiving the insertion end  114  of a second embodiment of the first fitting part  112 . The second fitting part  120  is shown with a plurality of circumferentially spaced apart slots  126 , while the second fitting part  120 ′ includes a single continuous circumferential slot  126 ′. An inspection hole or slot  128 ′ that extends to an outer surface of the second fitting part can be provided. 
     As shown in  FIG. 6 , the second embodiment of the first fitting part  112  is similar to the first fitting part  12  discussed above. It includes an insertion end  114  having an external circumferential groove  116 . Preferably, the first fitting part  112  has an annular cap  118  which includes at least one flow hole  128  and can optionally include at least one inspection hole  138 . The annular cap  118  of the first fitting part  112  contacts a top of the wall  124  of the second fitting part and acts as an outer barrier  132  for the curable liquid material  136  that is injected. Additionally, the insertion end  114  of the first fitting part preferably has a clearance of 0.08 inches or less with the opening  124  in the assembled position to form an inner barrier  134  for the curable liquid material to be injected. 
     Another embodiment of a fitting connection  110  for a thermal management valve module is provided, as shown in  FIG. 6 . Here, the first fitting part  112  as described above is provided. The thermal management valve module includes a wall portion that forms the second fitting part  120 ,  120 ′, as described above. The cured liquid material  136  is located in and fills the at least one flow hole  128  and a space defined between the external circumferential groove  116  of the first fitting part  112  and the at least one slot  126  in the second fitting part  120 ,  120 ′ to form a sealed, formed-locked connection between the first and second fitting parts  110 ,  120 ,  120 ′. This fitting connection  110  is both secure against heavy vibration and leak proof. Further, it requires little installation space for assembly and can be made in situ in an engine compartment of a motor vehicle. 
     Those skilled in the art will recognize that various modifications incorporating some or all of the elements of the fitting connections  10 ,  110  discussed above could be made while still achieving the desired sealed, formed-locked connection. 
     Fittings installed in this matter on a housing which comprises the second fitting part  20 ,  20 ′,  120 ,  120 ′ of a thermal management valve module provide a simply installed, highly effective sealing and locking arrangement which can withstand heavy vibration as well as the corrosive environment typical in motor vehicle engine compartments. With the second fitting part  20 ,  20 ′,  120 ,  120 ′ forming a wall portion of a thermal management valve module, the fitting connection  10  produced according to the invention is highly effective. 
     Having thus described the present invention in detail, it is to be appreciated and will be apparent to those skilled in the art that many physical changes, only a few of which are exemplified in the detailed description of the invention, could be made without altering the inventive concepts and principles embodied therein. It is also to be appreciated that numerous embodiments incorporating only part of the preferred embodiment are possible which do not alter, with respect to those parts, the inventive concepts and principles embodied therein. The present embodiment and optional configurations are therefore to be considered in all respects as exemplary and/or illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all alternate embodiments and changes to this embodiment which come within the meaning and range of equivalency of said claims are therefore to be embraced therein. 
     LIST OF ELEMENT NUMBERS 
     
         
         
           
               2  hose fitting 
               3  housing 
               4  screw 
               5  O-ring 
               6  gland 
               10  fitting connection 
               12  first fitting part 
               14  insertion end 
               16  external circumferential groove 
               18  annular cap 
               20 ,  20 ′ second fitting part 
               22  wall 
               24  opening 
               26 ,  26 ′ slot(s) 
               28  flow hole(s) 
               30  exterior of 2 nd  fitting part 
               32  outer barrier 
               34  inner barrier 
               36  curable liquid material 
               38  inspection hole 
               40  filling nozzle(s) 
               110  fitting connection 
               112  first fitting part 
               114  insertion end 
               116  external circumferential groove 
               118  annular cap 
               120 ,  120 ′ second fitting part 
               122  wall 
               124  opening 
               126 ,  126 ′ slot(s) 
               128  flow hole(s) 
               130  exterior of 2 nd  fitting part 
               132  outer barrier 
               134  inner barrier 
               136  curable liquid material 
               138  inspection hole