Patent Publication Number: US-2023144489-A1

Title: Line Coupling Assembly

Description:
BACKGROUND AND SUMMARY 
     The invention relates to a line coupling assembly for a motor vehicle. 
     In some countries, high demands are placed on line couplings in automotive construction. A diagnosis of the correct installation is prescribed by law in some countries, since damage relatively often occurs to a seal of the line coupling assembly during the assembly of conventional line coupling assemblies. 
     Such damage to the seal or other components of the line coupling assembly normally gradually leads to leakage of the line coupling assembly. 
     In addition, the assembly of conventional line coupling assemblies is relatively complex, since the lines are normally coupled via additional, separate securing means, for example screws or grooves. 
     The object of the invention is to provide a tight line coupling assembly which can be assembled and disassembled easily and quickly and in which a leak can be diagnosed quickly and easily. 
     According to the invention, this object is achieved by a line coupling assembly for a motor vehicle, in particular for ventilation lines of the motor vehicle, for example for ventilation lines of a crankcase, or ventilation lines of a tank, or other lines for fluids, in particular gaseous fluids. The line coupling assembly has a line coupling, a first line and a second line, which can be coupled to the first line via the line coupling, wherein the coupling-side ends to be connected of the lines each have a coupling component which, when the lines are completely coupled, interact such that the lines are coupled tightly to each other. When the lines are not completely coupled, the coupling components interact in such a way that there is a defined inspection gap in the area of the line coupling. Accordingly, when not completely coupled, the lines are not reliably coupled to each other, the inspection gap representing an intended leaky point by means of which the ability to diagnose the faulty incomplete coupling quickly and correctly can be ensured. Here, the defined inspection gap means that the size of the gap is defined or, in other words, that the gap has a defined size (height, width and/or length). 
     In particular, the line coupling is formed by the coupling components, which are each attached separately to the lines or are formed in one piece on the lines. 
     Provision can be made for the first line to comprise a female end piece and/or for the second line to comprise a male end piece, the end pieces each having the appropriate coupling component. The end pieces can be formed by the respective line or be attached separately to the respective line. 
     For example, the coupling component of the first line is assigned to an outer wall of the first line, in particular arranged or formed thereon, and/or the coupling component of the second line is assigned to an inner wall of the second line, in particular arranged or formed thereon. 
     According to one aspect, when completely coupled, the coupling components interengage in a form-fitting manner and/or the complete coupling can be released by rotating the lines relative to each other in their circumferential direction. Accordingly, the coupling comprises a type of bayonet connection. In this way, no screw connection or the like is necessary, as a result of which, firstly, quick and simple assembly and disassembly is possible and, secondly, no local deformations occur as a result of the local securing, for example by a screw connection, owing to which a leakage can be caused in other areas. 
     A further aspect provides for a seal to be arranged in the respective circumferential direction on an outer wall of the first line or on an inner wall of the second line, in particular in a circumferential groove in the wall, wherein the seal is arranged between the walls when the lines are coupled. When the lines are coupled completely by the coupling, the seal provides sealing between the walls. A tight coupling is thus created. If the lines are not completely coupled, the inspection gap is formed between the walls and is large enough that the seal can no longer provide sealing between the walls. Thus, a leaky coupling is created, wherein the incomplete coupling of the line can be diagnosed quickly and easily by way of the inspection gap and the leakage produced. 
     For example, the seal is a sealing ring and/or the groove is an annular groove, in particular a circumferential groove on the outer side. 
     A radially protruding sealing projection which presses radially against the seal when the lines are completely coupled can be provided on an outer wall of the first line or on an inner wall of the second line, in particular on the wall on which the seal is not arranged. In this way, the corresponding wall bears still more tightly against the seal, so that the tightness between the lines can be improved further. When the coupling is incomplete, the resulting inspection gap is large enough that the sealing projection no longer presses against the seal, at least in some sections. 
     In one embodiment, one of the coupling components is an indentation in a wall of the corresponding line which, starting from a coupling-side end face of the line, extends away from the coupling-side end face in the axial direction, in particular wherein the indentation ends in front of the seal in the axial direction. Part of the form-fitting connection is formed by the indentation, wherein the indentation has a boundary in front of the seal, so that the mating part of the form-fitting connection on the other line cannot be brought up as far as the seal or beyond the seal. In this way, damage to the seal is reliably prevented. 
     In particular, the indentation has a guide section and a fastening section, wherein, starting from the coupling-side end face, the guide section extends away from the coupling-side end face in an axial direction, and the fastening section adjoins the guide section in an axial direction at a distance from the coupling-side end face. By means of the guide section, the coupling components of the other line can be guided easily up to the fastening section and can be fastened easily and reliably in the fastening section, in particular by a form fit. Here, the guide section merges directly into the fastening section, so that the guide section and the fastening section are connected directly to each other. 
     For example, the fastening section, seen in the radial direction, is deeper than the guide section. Thus, the coupling component of the other line can be accommodated in the fastening section, in particular the coupling component of the other line engaging behind the guide section in a form-fitting manner, which forms a form-fitting latching connection. 
     In one embodiment, the fastening section is adjoined in the circumferential direction of the corresponding line by at least one ramp section, which connects a surface of the wall in which the indentation is arranged to a base area of the indentation. In this way, the coupling component of the other line which engages in the fastening section can move out of the fastening section along the ramp section toward the surface of the wall as a result of the lines being rotated relative to each other in the circumferential direction. As a result, the form fit is cancelled and the lines can easily be separated from each other. 
     A further embodiment provides for the guide section to have lateral guide walls which delimit a guide channel, the guide channel tapering from the coupling-side end face toward the fastening section. Thus, a wide “entry area” can be created on the coupling-side end face, as a result of which the coupling component of the other line can easily be introduced into the guide section and can be reliably guided to the fastening section by the guide walls. 
     For example, one of the coupling components is a latching lug protruding in a radial direction on one of the walls, in particular wherein the latching lug is spaced further apart in an axial direction from a coupling-side end face of the corresponding line than the seal. The latching lug can be guided along the guide section of the indentation to the fastening section of the indentation and can latch into the fastening section, as a result of which the guide section is gripped from behind. With respect to the wall of the line having the latching lug, the seal is arranged between the end face and the latching lug. 
     In particular, the latching lug extends in the manner of a ramp in an axial direction toward the wall to a coupling-side end of the corresponding line and/or, at the end facing away from the coupling-side end, the latching lug extends substantially orthogonally toward the wall, so that a step is formed. As a result of the ramp-like section, the latching lug can slide easily on the end face of the other line and can be pushed onto the guide section. In the completely coupled state, the orthogonal section rests on a wall of the fastening section which is opposite the end face, as a result of which the form-fitting coupling is made. 
     When the lines are completely coupled, the latching lug can be accommodated in the fastening section of the indentation. Accordingly, the latching lug is latched in the indentation, which achieves the form-fitting coupling. 
     Further advantages and features of the invention will become apparent from the following description and from the appended drawings, to which reference is made. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    shows a schematic illustration of a line coupling assembly in an uncoupled state, 
         FIG.  2    shows a schematic longitudinal section A-A of a line according to the invention of the line coupling assembly according to the invention according to  FIG.  1   , 
         FIG.  3    shows a schematic cross section B-B of the line according to the invention according to  FIG.  2   , 
         FIG.  4    shows a schematic longitudinal section C-C of a further line according to the invention of the line coupling assembly according to the invention according to  FIG.  1   , 
         FIG.  5    shows a schematic illustration of the line coupling assembly according to the invention in a completely coupled state, and 
         FIG.  6    shows a schematic cross section D-D of the line coupling assembly according to the invention according to  FIG.  5   . 
     
    
    
     DETAILED DESCRIPTION 
     A line coupling assembly  10 , which is provided to couple fluid-carrying lines, is shown in  FIG.  1   . 
     The line coupling assembly  10  comprises a first line  12  and a second line  14 , through which an appropriate fluid can flow. At their opposite ends, the lines  12 ,  14  each have parts of a coupling  16 , via which the lines  12 ,  14  can be coupled to each other. The coupling  16  is also designated as line coupling. 
     The first line  12  here has a male end piece as part of the coupling  16 , and the second line  14  here has a female end piece as part of the coupling  16 . 
     The end pieces can be attached to the opposite ends of the lines  12 ,  14  as a separate part. 
     Alternatively, the end pieces can be formed in one piece on the lines  12 ,  14 , so that the respective line  12 ,  14  also forms the respective end piece. 
     In principle, a fluidic connection between the lines  12 ,  14  is produced via the coupling  16  in its coupled state. 
     A seal  17  is provided on the first line  12 . The seal  17  encloses the first line  12  in the circumferential direction or, in other words, extends along the entire circumference of the first line  12 . Accordingly, the seal  17  constitutes an annular seal. 
     Each line  12 ,  14  has a coupling component  18  and  20 , respectively, in the area of the coupling  16 . 
     The coupling component  18  is formed as an indentation, which is arranged or formed in an outer wall  22  of the first line  12 . 
     Starting from the coupling-side end face  24  of the first line  12 , the indentation extends in an axial direction away from the coupling-side end face  24  in the direction of the seal  17 . 
     The indentation ends in front of the seal  17 . 
     The coupling component  18  or the indentation is accordingly arranged between the seal  17  and the coupling-side end face  24 , seen in the axial direction. 
     The coupling component  18  comprises a guide section  26  and a fastening section  28 . 
     The guide section  26  adjoins the coupling-side end face  24  and, starting therefrom, extends in an axial direction away from the coupling-side end face  24 . 
     At a seal-side end or at an end opposite to the coupling-side end face  24 , the fastening section  28  is flush with the guide section  26 . The guide section  26  merges directly or indirectly into the fastening section  28 . 
     The guide section  26  forms lateral guide walls  30 , the distance of which in relation to one another decreases with increasing distance from the coupling-side end face  24 . The guide walls  30  form a guide channel which, because of the decreasing distance between the guide walls  30 , tapers toward the fastening section  28 . 
       FIG.  2    shows a partial longitudinal section A-A of the first line  12 . 
     At a distance from the coupling-side end face  24  and the coupling component  18 , a groove  32  is formed in the outer wall  22  in the circumferential direction of the first line  12 . The seal  17  is accommodated in this groove  32 . 
     The groove  32  extends along the entire circumference of the first line  12 . 
     Accordingly, the groove  32  constitutes an annular groove. 
     The fastening section  28  has a larger penetration depth into the wall  22  than the guide section  26 . As a result, a step  34 , which has a contact surface  36  opposite to the coupling-side end face  24 , is formed between the fastening section  28  and the guide section  26 . 
     As can be seen from  FIG.  1   , the coupling component  18  has two ramp sections  38  which, in the circumferential direction of the first line  12 , directly adjoin the fastening section  28 . Accordingly, the ramp sections  38  merge directly into the fastening section  28 . 
     As revealed by  FIG.  3   , which shows a partial cross section B-B of the first line  12 , the ramp sections  38  are angled at an angle α with respect to a base area  40  of the fastening section  28 . 
     The ramp sections  38  connect the base area  40  of the fastening section  28  to a surface of the outer wall  22 . The surface of the outer wall  22 , the ramp areas of the ramp section  38  and the base area  40  of the fastening section  28  are thus connected to one another continuously, with no abrupt jumps, such as steps, for example, being provided. 
     The angle α lies in a range from 100° to 170°, in particular in a range from 120° to 150°, preferably in a range from 130° to 140°. 
     For example, the angle α is substantially 135°. 
     A partial longitudinal section C-C of the second line  14  is illustrated in  FIG.  4   . 
     The coupling component  20  here is arranged on an inner wall  42  of the second line  14 . The coupling component  20  here protrudes in a radial direction from the inner wall  42 . 
     For example, the coupling component  20  is formed as a latching lug. 
     The coupling component  20  extends in the manner of a ramp in an axial direction toward the inner wall  42  to a coupling-side end of the second line  14 . As a result, a wedge-shaped section is formed, which has a first sliding surface  44 . 
     At an end of the coupling component  20  that faces away from the coupling-side end, the coupling component  20  has a step-shaped section  46 , which comprises a second sliding surface  48  substantially parallel to the inner wall  42  and a contact surface  50  substantially orthogonal to the inner wall  42 . 
     Between a coupling-side end face  52  and the coupling component  20 , the second line  14  has an intermediate area  54 . 
     A radially protruding sealing projection  56  can optionally be provided in the intermediate area  54 . 
     In  FIG.  5   , the line coupling assembly  10  is shown in a completely coupled state, an upper area of the second line  14  having been cut out. 
     Here, the first line  12  is pushed with its male end piece into the female end piece of the second line  14  in such a way that the coupling component  20  of the second line  14  is accommodated in the coupling component  18  of the first line  12 . More precisely, the latching lug of the second line  14  extends into the fastening section  28  of the first line  12 . 
     The contact surface  50  of the latching lug engages behind the contact surface  36  of the fastening section  28 . In this way, a form fit is formed, which prevents the lines  12 ,  14  moving apart relative to each other in an axial direction. 
     In the intermediate area  54 , which means between the coupling-side end face  52  and the coupling component  20 , the seal  17  acts in a sealing manner on the inner wall  42  of the second line  14 . 
     By means of the seal  17 , a spacing or gap  58  between the outer wall  22  of the first line  12  and the inner wall  42  of the second line  14  is sealed off over the complete circumference of the coupling  16 . 
     Optionally, the sealing protrusion  56  can interact with the seal  17  in order to seal off the gap  58 . 
       FIG.  6    shows a partial cross section D-D of the line coupling assembly  10  in an incompletely coupled state. 
     Here, the coupling component  20  is not accommodated in the fastening section  28 —as in the completely coupled state—but is located in the guide section  26 . 
     Since the guide section  26  does not have such a large penetration depth as the fastening section  28 , the distance between the outer wall  22  of the first line  12  and the inner wall  42  of the second line  14  is greater than in the completely coupled state. As a result, a substantially larger gap  58  which exceeds the height of the seal  17  is formed, so that the seal  17  can no longer act in a sealing manner on the inner wall  42 . 
     The distance between the seal  17  and the inner wall  42  corresponds to a defined inspection gap  60 . 
     The defined inspection gap has a defined size (height, width and/or length) which, for example, is defined via the radial distance of the second sliding surface  48  of the coupling component  20  from the inner wall  42  and/or via the penetration depth of the guide section  26  into the outer wall  22 . 
     The coupling  16  is accordingly not tight in the area of the inspection gap  60 , which produces a leak. This leak can be diagnosed easily and quickly. 
     Of course, the inspection gap  60  is also produced when the coupling component  20  is not arranged on the guide section  26  but, for example, also on the surface of the outer wall  22 . 
     The coupling and uncoupling process is discussed below. 
     For the coupling, the lines  12 ,  14  are moved toward each other, so that the first line  12  penetrates the second line  14 . The coupling-side end face  24  of the first line  12  is moved against the first sliding surface  44  of the coupling component  20  of the second line  14 . The first sliding surface  44  slides on the coupling-side end face  24 , so that the coupling component  20  is moved outward in a radial direction, as a result of which the entire wall of the second line  14  in the area of the coupling component  20  is outwardly deformed. In this phase, the inspection gap  60  is formed between the seal  17  and the inner wall  42 . The coupling component  20  then slides with its second sliding surface  48  along the guide section  26  toward the fastening section  28 . In this phase, the inspection gap  60  remains. During a further relative axial displacement of the coupling components  18 ,  20  in relation to each other, the coupling component  20  is accommodated completely in the fastening section  28  and latches in the fastening section  28 , as a result of which the deformation of the wall of the second line  14  is eliminated. Thus, the inspection gap  60  is closed and the inner wall  42  bears in a sealing manner against the seal  17  over its entire circumference. The contact surface  50  of the coupling component  20  engages behind the contact surface  36  of the fastening section  28  or the coupling component  18 . In this way, an axial displacement of the lines  12 ,  14  away from each other is prevented. Complete coupling of the lines  12 ,  14  is achieved. 
     To uncouple the two lines  12 ,  14 , the two lines  12 ,  14  are rotated relative to each other in the circumferential direction. The coupling component  20  slides with its second sliding surface  48  out of the fastening section  28 , over one of the ramp sections  38 , onto the surface of the outer wall  22  of the first line  12 . The inspection gap  60  is produced in this process. On the surface of the outer wall  22 , the coupling component  20  and, accordingly, the entire line  14  can be pushed down axially from the first line  12 , so that the two lines  12 ,  14  can be moved away from each other without problems. The lines  12 ,  14  are then completely uncoupled. 
     Thus, the uncoupling is carried out in a similar way to a bayonet connection. 
     The embodiments shown in the figures are to be understood merely by way of example. The features of the individual components can be interchanged or combined with one another as desired. Thus, for example, the seal  17  can be provided not on the outer wall  22  but on the inner wall  42 . Alternatively or additionally, the coupling components  18 ,  20  can be interchanged.