Abstract:
In a fluid line coupling, there is an electrically heatable heating element ( 14 ) in order to heat a fluid flowing in a fluid line cavity ( 7 ), said heating element being held with an axial prestress against sealing means ( 21 ) by a securing means ( 22 ) in a connecting part ( 8 ) of a coupling body ( 1 ) of the fluid line coupling. As a result, a high degree of tightness is obtained.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application is a U.S. National Phase Patent Application based on International Application Serial No. PCT/EP2008/005618 filed Jul. 10, 2008, the disclosure of which is hereby explicitly incorporated by reference herein. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to a fluid line coupling. 
         [0004]    2. Description of the Related Art 
         [0005]    One fluid line coupling is known, for example, from DE 43 00 037 C1. The prior fluid line coupling is provided with a coupling body having a connector for a line of a fluid line arrangement, and is equipped with a receiving part configured to receive a plug-in part that is connected to another line of the fluid line arrangement. Extending between the connector and the receiving part is a fluid line cavity through which a fluid flows in the installed situation, i.e., that of being integrated into the fluid line arrangement. 
         [0006]    Known from JP 2006-125480 is a line connection arrangement comprising a tubular, bent heating wire that is fitted to the contour of a sealing unit. 
       SUMMARY OF THE INVENTION 
       [0007]    The invention provides a fluid line coupling that ensures the reliable passage of a fluid flowing through the fluid line coupling, even at relatively low temperatures. 
         [0008]    By virtue of the fact that the fluid line coupling according to the invention comprises an electrically heatable heating element that is inserted in the connecting part and is coupled in a fluid-tight manner via the sealing means, a fluid flowing in the fluid line cavity can be heated very efficiently over the relatively large-area contact region that is in thermodynamic contact with the fluid line cavity. 
         [0009]    In one form thereof, the present invention provides a fluid line coupling provided with a coupling body that has a connector for a line of a fluid line arrangement and is equipped with a receiving part configured to receive a plug-in part that is connected to another line of the fluid line arrangement, wherein a fluid line cavity extends between the connector and the receiving part, characterized in that configured on the coupling body is a sleeve-like connecting part that is open to the outside and that gives into the fluid line cavity, in that a heating element that can be heated by electric power is present and can be inserted into the connecting part and has a contact region which in the inserted arrangement of the heating element forms a wall region of the fluid line cavity, in that a sealing unit is present and is disposed between the connecting part and the heating element, and in that securing means are present and hold the heating element fluid-tightly in the connecting part. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]    The above mentioned and other features and objects of this invention, and the manner of attaining them, will become more apparent and the invention itself will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, wherein: 
           [0011]      FIG. 1  is a partially sectional side view of a first exemplary embodiment of a fluid line coupling according to the invention, with a heating element having a flat fluid-contact surface; 
           [0012]      FIG. 2  is a sectional detail view of another exemplary embodiment of a fluid line coupling according to the invention, with a heating element comprising a fluid-contact sleeve; and 
           [0013]      FIG. 3  is a sectional detail view of another exemplary embodiment of a fluid line coupling according to the invention, with a heating element comprising a fluid-contact mandrel and with a thermally insulating intermediate element. 
       
    
    
       [0014]    Corresponding reference characters indicate corresponding parts throughout the several views. Although the exemplifications set out herein illustrate embodiments of the invention, in several forms, the embodiments disclosed below are not intended to be exhaustive or to be construed as limiting the scope of the invention to the precise forms disclosed. 
       DETAILED DESCRIPTION 
       [0015]      FIG. 1  is a partially sectional side view of an exemplary embodiment of a fluid line coupling according to the invention, comprising a coupling body  1  made of a hard elastic synthetic material. The coupling body  1  comprises a substantially cylindrical receiving part  2 , which is configured to receive a plug-in part (not shown in  FIG. 1 ) to which a line of a fluid line arrangement (also not shown in  FIG. 1 ) can be connected by means of the fluid line coupling. To connect the plug-in part to the coupling body  1 , formed at one end of the receiving part  2  is an approximately square socket  3  for a locking part  4  that is to be inserted in said socket  3 . 
         [0016]    At the end of receiving part  2  facing away from socket  3 , attached, as a connector, at a bracket portion  5  is a connection fitting  6 , to which can be connected another line (not shown in  FIG. 1 ) of the fluid line arrangement that is then fluidically connected, via a fluid line cavity  7  extending through the coupling body  1 , to the line that is connected to the plug-in part inserted in the receiving part  2 . 
         [0017]    Configured on the coupling body  1  at the opposite end of bracket portion  5  from receiving part  2  and in axial prolongation of receiving part  2  is a sleeve-like connecting part  8 , which, on the one hand, opens by a cylindrical mouth portion  9  into the fluid line cavity  7 , and, on the other hand, is open to the outside in the direction pointing away from fluid line cavity  7 . On the radially inward-facing inner face, connecting part  8  presents an abutment shoulder  10 , which extends from mouth portion  9  radially outward perpendicularly to the longitudinal axis of connecting part  8 . From the abutment shoulder  10 , a cylindrical socket portion  11  extends axially outward away from mouth portion  9 , and has attached to its end spring arms  12  that extend in the longitudinal direction of connecting part  8  and are elastic in the radial direction. Each spring arm  12  has, formed at its end directed away from socket portion  11 , a respective snap nose  13  that extends outward in the radial direction. 
         [0018]    The fluid line coupling according to the invention is also equipped with a heating element  14 , which is made from a synthetic material that is electrically conductive, for example due to the addition of carbon particles or metal particles, and has a positive temperature coefficient. In the representation according to  FIG. 1 , heating element  14  is inserted in connecting part  8  and comprises frontally a first cylinder portion  15 , which is disposed flush in mouth portion  9  and forms, in the region of bracket portion  5 , a wall region of the fluid line cavity  7  in the form of a frontal, flat, fluid-contact surface  16  that faces toward receiving part  2  and serves as a large-area thermodynamic contact region. 
         [0019]    Heating element  14  also comprises, joined to first cylinder portion  15  on the side facing away from fluid-contact surface  16 , a second cylinder portion  17  with a larger diameter than first cylinder portion  15 , with the result that a pressure shoulder  18 , disposed opposite abutment shoulder  10 , is formed between first cylinder portion  15  and second cylinder portion  17 . Second cylinder portion  17  is inserted flush into socket portion  11  and protrudes axially outward beyond the spring arms  12  by a pressure face  19  that is oriented perpendicular to the longitudinal axis of connecting part  8 . 
         [0020]    Embedded in heating element  14  in this exemplary embodiment are two metal connector pins  20 , which extend from first cylinder portion  15  all the way through second cylinder portion  17  to protrude outward beyond pressure face  19 . The connector pins  20  are connected to an electric power supply (not shown in  FIG. 1 ) by means of which an electrical current can be fed to the connector pins  20  to effect direct proportional heating of the heating element  14  by virtue of the positive temperature coefficient of said heating element  14 . 
         [0021]    In the assembled arrangement of coupling body  1  and heating element  14 , disposed as a sealing unit between abutment shoulder  10  and pressure shoulder  18  is an annular, closed sealing ring  21  made of a soft elastic material, which surrounds the first cylinder portion  15  of heating element  14  and bears by its outer face against the inner wall of socket portion  11 , said sealing ring  21  being biased in the radial direction in this arrangement. 
         [0022]    The fluid line coupling according to the invention is further provided with securing means comprising a securing ring  22  made of a hard elastic material, which in the assembled arrangement of the fluid line coupling outwardly surrounds connecting part  8 . Securing ring  22  is provided, on its side that faces toward receiving part  2  in the assembled arrangement, with a snap collar  23 , which extends radially inwardly and in the assembled arrangement according to  FIG. 1  engages behind the snap noses  13 , thereby securing the securing ring  22  against axial displacement away from coupling body  1 . Securing ring  22  also has, on its opposite side from snap collar  23 , a pressure collar  24 , which also extends radially inwardly and in the assembled arrangement of the fluid line coupling bears outwardly, in this exemplary embodiment, against the pressure face  19  of heating element  14 . The dimensions of heating element  14  and of securing ring  22  in this case are so adapted to one another in the longitudinal direction that in the assembled arrangement of the fluid line coupling, the heating element  14  is pressed against the sealing ring  22  with a certain axial pressure force. 
         [0023]    Sealing ring  21  is thereby subjected to an axial pressure force in addition to the radial pressure force, thus substantially increasing the sealing effect. This is highly advantageous particularly since, despite the reduction of the mechanical strength of the heating element  14  that occurs with increasing heating, the high sealing effect is nevertheless substantially maintained by the continual axial pressure of sealing ring  21  against abutment shoulder  10  and against pressure shoulder  18  that is induced by securing ring  22 . 
         [0024]      FIG. 2  is a sectional detail view of another exemplary embodiment of a fluid line coupling according to the invention in the region of connecting part  8 , it being noted that like elements in the exemplary embodiments according to  FIG. 1  and  FIG. 2  are provided with the same reference numerals and will not be described more closely below. In the exemplary embodiment according to  FIG. 2 , to create a thermodynamic contact region, heating element  14  is configured with a hollow-cylinder-like fluid-contact sleeve  25 , which is formed onto the end of first cylinder portion  15  that is directed away from second cylinder portion  17 . In the region of bracket portion  5 , fluid-contact sleeve  25  abuts the inner wall of fluid line cavity  7 , with the result that the radially inward-facing inner wall  26  of fluid-contact sleeve  25 , as the interior wall, together with a flat end wall  27  that extends between the fluid-contact sleeve  25  and is configured at the end of first cylinder portion  15  that faces toward fluid line cavity  7 , forms the entire, very large-area thermodynamic contact region. 
         [0025]    To enable fluid to flow through the fluid line coupling, fluid-contact sleeve  25  is pierced by a penetrating opening  28  in the region of the connection of connection fitting  6  to bracket portion  5 . Alignment means (not shown in  FIG. 2 ) formed on coupling body  1  and on heating element  14  serve to ensure that penetrating opening  28  is disposed in the connection region of connection fitting  6  when securing ring  22  engages behind snap noses  13 . 
         [0026]      FIG. 3  is a sectional detail view of another exemplary embodiment of a fluid line coupling according to the invention in the region of connecting part  8 , it being noted that like elements in the exemplary embodiments according to  FIG. 1 ,  FIG. 2  and  FIG. 3  are provided with the same reference numerals and will not be described more closely below. In the exemplary embodiment according to  FIG. 3 , a thermodynamic contact region of heating element  14  is formed by a solid, cylinder-like fluid-contact mandrel  29 , which is disposed on the end face of first cylinder portion  15  facing toward receiving part  2  and is situated centrally and spaced away from the inner face of fluid line cavity  7 , and by a flat fluid-contact marginal area  30  outwardly surrounding fluid-contact mandrel  29 . A very large-area contact region is also formed in this way. 
         [0027]    In the exemplary embodiment depicted in  FIG. 3 , in deviation from the previously described exemplary embodiments, the securing ring  22  is attached to connecting part  8  by a weld joint  31 . 
         [0028]    Additionally, in the exemplary embodiment according to  FIG. 3 , disposed between the heating element  14  and the pressure collar  24  of securing ring  22  is an intermediate element  32  in the form of a flat plate made from a low-thermal-conductivity, hard-elastic synthetic material, in order to thermally insulate heating element  14  from securing ring  22  and thus ensure the persistence of the axial bias, even over very long periods of time spanning numerous heating cycles. With a view toward especially good thermal insulation, the intermediate element  32  is configured, on its side facing toward heating element  14 , with a number of insulating cavities  33  that are open to heating element  14  and reduce heat transfer to the securing ring  22  compared to a completely solid embodiment. 
         [0029]    While this invention has been described as having a preferred design, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.