Abstract:
In a sealing arrangement, in particular for the connection of a manifold to a cylinder head of an internal combustion engine, a flat support ( 1, 3 ) has at least one sealing element in the form of a ring element ( 17 ) that forms a mold seal. The support ( 1, 3 ) and ring element ( 17 ) form a unit that holds the ring element captively on the support ( 1, 3 ).

Description:
FIELD OF THE INVENTION 
   The present invention relates to a sealing arrangement, in particular for the connection of a manifold to a cylinder head of an internal combustion engine, with a flat support and at least one sealing element in the form of a ring element forming a mold seal. 
   BACKGROUND OF THE INVENTION 
   Sealing arrangements of this type are widely used for the connection of exhaust-gas-carrying pipes to cylinder heads of internal combustion engines. Based on the high exhaust gas temperatures that occur, both flat supports of the sealing arrangement and the respective ring element are metallic components with smaller wall thickness in each case. The ring element usually has a profiled configuration. 
   In a disadvantageous way, the assembly process of such multi-part sealing arrangements is configured in a comparatively complicated manner. During production of the connection with the cylinder head, care must be taken that the ring element is actually present and correctly positioned between the respective connecting parts. 
   SUMMARY OF THE INVENTION 
   An object of the present invention is to provide a sealing arrangement, particularly for the connection of a manifold to a cylinder head of an internal combustion engine, in which the assembly process can be performed comparatively more simply and more safely. 
   According to the present invention, this object is basically achieved by a sealing arrangement forming a unit that captively contains the ring element. The entire operating sequence is configured in an especially simple and safe manner during use since neither during the supply of the sealing arrangements in the actual assembly position, which takes place in an automated fashion in industrial manufacturing, nor in the actual connecting process must it be ensured whether or not the ring element is present and correctly positioned. 
   In advantageous embodiments in which the support has a flat plate with at least one opening for a gas flow, preferably an exhaust gas flow, the ring element extends along the edge of the respective opening. 
   Preferably, the ring element that forms the mold seal has the shape of a C-profile opening radially outwardly and raising from the plane of the plate. The arrangement can be designed such that the end area of the C-profile adjacent to the plane of the plate forms a slight curvature on the side of the plate that is set against the end of the C-profile that is raised from the plane. 
   In an especially advantageous way, the ring element is formed by the edge of the opening that is integral with the plate and that is raised from the plane of the plate. The ring element or elements therefore forms/form an integral component of the plate. 
   In the production of such embodiments, the procedure may be that by piercing the plate, first the opening or openings is/are formed. The respective opening edge is then raised and is thereafter turned over outward by applying pressing force to form the C-profile. In such a pressing or molding process, the lower end area of the C-profile interconnecting with the plate can form a slight curvature on the side of the plate opposite the end of the C-profile and raised from the plane. Such examples are characterized by an especially good sealing action. 
   When the ring element does not form any integral component of the plate, but rather is a separate component, the arrangement can be designed such that a holding device produces a frictional connection between plate and ring element and is provided to secure the ring element captively to the plate. 
   In advantageous embodiments, retaining collars project slightly radially outward and are molded onto the edge of the C-profile opposite the edge of the ring element raised from the plane of the plate. The projections flexibly deform radially inward in the plate&#39;s respective opening when the ring element is attached, thereby creating a frictional connection. The effect of this deforming is to generate a holding force. 
   In the way conventional in sealing arrangements for the connection of exhaust gas manifolds, the plate can have several openings, arranged at a distance from one another, for the passage of a respective exhaust gas flow. For example, the plate can have the shape of a gland with two plate areas, in which one opening each is provided connected to one another by a plate arm. The plate arm has a smaller width compared to these plate areas. 
   To promote a thermal decoupling between cylinder head and the hot exhaust gas manifold, the plate preferably has openings divided around the respective openings for gas flows. Round holes or crescent-shaped holes can then be provided that surround the respective openings. 
   Other objects, advantages and salient features of the present invention will become apparent from the following detailed description, which, taken in conjunction with the annexed drawings, discloses preferred embodiments of the present invention. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Referring to the drawings which form a part of this disclosure: 
       FIG. 1  is top plan view of a sealing arrangement according to first and second exemplary embodiments of the present invention in the form of a gland for use in the attachment connection between an exhaust gas manifold and a cylinder head, with different embodiments being shown on the right side and the left side in the figure, in which differently molded openings for a thermal decoupling are provided; 
       FIG. 2  is a side elevational view in section taken along line II-II in  FIG. 1 ; 
       FIG. 3  is a partial side elevational view in section with the area III in  FIG. 2  depicted greatly enlarged; 
       FIG. 4  is a top plan view of the ring element, used as a sealing element, of a third exemplary embodiment of the sealing arrangement according to the present invention; 
       FIG. 5  is a greatly enlarged detail top plan view of the area V in  FIG. 4 ; 
       FIG. 6  is a partial side elevational view in section of the ring element of  FIG. 4 , greatly enlarged compared to  FIG. 4  with the associated edge section of the opening of a plate, in the condition before attaching the ring element on the plate; and 
       FIG. 7  is a partial side elevational view in section corresponding to  FIG. 6 , with the ring element shown after the plate is inserted into the opening. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   The present invention will be explained in greater detail below on the basis of examples, in which the sealing arrangement has the shape of a gland. A flat metal plate forms the support of the sealing arrangement and has two plate areas  1  and  3  integrally connected together via a comparatively narrow plate arm  5 . The arm  5  connects the central areas of the plate areas  1  and  3  to one another and extends along the longitudinal axis  7  of the sealing arrangement. About the center  9  of the circle located on the longitudinal axis  7 , there is a circular opening  11  for the passage of an exhaust gas flow emerging from a respective exhaust opening of a cylinder head (not shown), in each plate area  1  and  3 . Screw holes  13  are located in two plate areas  1  and  3  for fastening screws attaching the manifold (not shown) and the sealing arrangement to the cylinder head. 
   In addition to the screw holes  13 , holes  15  in the plate areas  1  and  3  reduce the heat-conducting surface of the sealing arrangement, and thus, form a thermal decoupling between cylinder head and exhaust gas manifold. In  FIG. 1 , two different embodiments are illustrated for the holes  15 . Specifically, crescent-shaped holes  15  are provided in the plate area  1  on the left, while holes  15  in the form of round holes are provided in the plate area  3  on the right. 
     FIGS. 1 to 3  relate to an embodiment in which for each opening  11 , a sealing element forming a component of the sealing arrangement is formed by a ring element  17 . Ring element  17  is integrally formed with the respective plate area  1  and  3  in each case, such that the opening edge is raised on the respective opening  11  of the opening edge. To form a C-profile  19 , the end area of the raised edge is turned radially outward by applying a compressive or pressing force to form the profile shape shown in  FIG. 3 . By this shaping, a slight curvature  23  is produced on the side of the plate areas  1 ,  3  opposite the raised end  21  of the C-profile  19 . The curvature on this side of the plate areas  1 ,  3  forms a flat layer crimp that projecting relative to and extending around the latter. The curvature  23  projects by 0.5 to 3, preferably by 1 sheet-metal thickness of the plate relative to the areas  1 ,  3  thereof. 
     FIGS. 4 to 7  illustrate another embodiment. Instead of the above-described ring element  17  integral with the respective plate area  1 ,  3 , a separate metal ring element  25  is provided also having the shape of a C-profile  19 . As is the case in the plate with the plate areas  1  and  3 , the ring element  25  is also a thin-walled metal component whose wall thickness, as is the case with the plate, is, for example, in the range of 0.3 mm. For a captive attachment of the ring element  25  on the respective opening  11  in the associated plate area  1 ,  3 , the ring element  25  has three retaining collars  27  on the profile edge opposite its outer end or edge  21 . The retaining collars are distributed uniformly on the periphery of the ring element  25 , see  FIG. 4 . As shown most clearly by the enlarged view of  FIG. 5 , the retaining collars  27  in (undeformed) initial conditions form claw-like projections that project slightly radially on the respective peripheral edge  26  of the ring element  25 . 
     FIG. 6  shows the initial condition shortly before the application of the ring element  25  on the edge of the opening  11  of the respective plate area  1 ,  3 . The retaining collars  27  extend slightly radially outwardly over or radially outwardly beyond the edge of the opening  11 . If the ring element is forced into the opening  11  by applying a compressive force corresponding to the force arrow  29 , a flexible deformation of the retaining collars  27  occurs when pressing the ring element into the opening  11 , see  FIG. 7 . A frictional connection acting as a holding force is then produced on the opening  11 , by which the ring element  25  is held captively on the opening  11 . The free ends of the retaining collars  27  in each case are supported flush with the inside wall or inside edge that delineates the opening  11 . Based on the oblique arrangement of the retaining collars  27 , the outside corner edges (cf.  FIG. 7 ) of the collars come into linear contact with the inside wall or edge of the opening  11  relative to the plate areas  1 ,  3 . A very high edge pressing force then takes place making it possible to mount the ring element  25  securely in the opening  11  of the plate despite the flexing of the retaining collars  27 . The ring element can also be easily detached for repair purposes. 
   The ring element  25  can be easily replaced with a new part. Additionally, with inclusion of common manufacturing tolerances, the respective retaining collar arrangement of three retaining collars  27  allows a very exact hub centering of the ring element  25  in the opening  11  to effect a reliable sealing system. The retaining collars  27  preferably wind up at a steep oblique angle resting on the external edge of the free opening  11 . 
   The ring element  25  can be slightly deformed in a similar way on its peripheral edge  26  that has the retaining collars  27  by the compressive forces that are exerted when it is depressed, as is shown in  FIG. 3  for the ring element  17 , where a slight curvature  23  is produced by the compressive force that forms the C-profile  19  below the plate  1 ,  3 .  FIG. 7  also shows a corresponding curvature  23  for the ring element  25  on its edge opposite the profile end  21  (peripheral edge  26  in  FIG. 5 ). The respective retaining collar  27  extends from this curvature  23  in an oblique support angle of between 30° to 60°, preferably about 45°, in the inside edge of the opening  11 , by which the curvature  23  is supported and is held in its sealing position, to improve the sealing in this respect. 
   To enhance this supporting action, as  FIG. 5  shows, the respective retaining collar  27  in the C-profile  19  is provided on both sides with one recess each. Each recess forms an indentation in the adjacent profile wall to further improve the flexible holding action for the individual retaining collar  27 . Moreover, at a buckling point ( FIG. 7 ), the arc-shaped profile  19  shown in cross-section ( FIG. 6 ) undergoes transition into the retaining collar  27  extending at an oblique angle and is straight at this point. The buckling point is arranged in a virtual vertical extension below the free profile end of the C-profile  19  located above it. 
   The term “sealing ring or mold” also extends to ring embodiments with an oval shape or those with a rectangular design. Preferably, the corners of the rectangle are designed in a rounded way. Other ring forms are possible here. For this purpose, the respective images of the mold or sealing ring preferably follow the respective geometry thereof. 
   While various embodiments have been chosen to illustrate the invention, it will be understood by those skilled in the art that various changes and modifications can be made therein without departing from the scope of the invention as defined in the appended claims.