Abstract:
A connection for connecting tubular air guide element to a turbocharger includes a tubular nipple having a connection end provided with first set of locking element and an air guide element having a connection end provided with a second set of locking elements. A bayonet ring having locking elements is received over the connection ends and forms a bayonet coupling, coupling the tubular nipple and air guide element in a sealed manner.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates to a connector for connecting a tubular air duct or conduit to a turbocharger. 
     Profusner, U.S. Pat. No. 5,855,399 (=EP 750,152) discloses a plug-in connection, which is intended for joining pipelines and hose lines and is designed in particular for use in duct systems of motor vehicles. This plug-in connection comprises an inner sleeve and an outer sleeve, both of which accommodate a pipeline or hose line between them so that a pipe socket may be pushed over the outer sleeve and can be snap locked with the outer sleeve with the aid of securing means. The securing means consists of a wire hoop. Therefore, the outer periphery of the pipe socket exhibits at least one radial bulge, which extends in the longitudinal direction; and in the area of the bulge the pipe socket exhibits in the circumferential direction an aperture, through which a part of the wire bow engages. The bulge is associated with a projection, which is located on the outer sleeve and with which the wire bow interacts. 
     SUMMARY OF THE INVENTION 
     It is an object of the invention to provide an improved connector for connecting a tubular air conduit to a connecting pipe. 
     Another object of the invention is to provide a connector for connecting an air conduit to a connecting pipe which can be assembled or connected in a simple fashion. 
     A further object of the invention is to provide a connector which is especially adapted for connecting an air conduit to a turbocharger of an internal combustion engine. 
     These and other objects are achieved in accordance with the present invention by providing a connection for connecting tubular air guide element to a turbocharger, the turbocharger having a tubular nipple which is disposed on a housing of the turbocharger and to which an end of the air guide element is to be connected in a sealed manner, wherein the tubular nipple and the air guide element are provided adjacent their respective ends which are to be connected with a locking element comprising integral projections which form at least one bayonet coupling. 
     The connector of the invention is simple to construct and easy to assemble, and, in addition, the necessary plug-in length is short. Due to the relative rotation of the two parts to be connected, a only a small mounting force is required in order to achieve a high clamping force. 
     In accordance with a preferred embodiment of the invention, the bayonet coupling is formed by a locking element, which advantageously comprises at least two radial engaging members that are distributed around the circumference of the pipe nipple and the air guide element and extend as segments over a curved section of the respective circumference. In order to realize the bayonet coupling, it is particularly advantageous to provide a bayonet ring which is secured to the tubular nipple of the turbocharger by a first bayonet coupling and is connected to the air guide element by a second bayonet coupling. In this way it is possible to arrange the segments for the bayonet coupling to the tubular nipple of the turbocharger and to the air guide element in each case on the outer peripheral surface, which is more advantageous for manufacturing the parts. The respective mating parts for the first and the second bayonet couplings are arranged on the inner circumference of the bayonet ring. Thus, the segments on the tubular nipple and the air guide element are oriented to project radially outwardly; and the segments on the bayonet ring are oriented to project radially inwardly. 
     In another embodiment of the invention, a sealing ring is arranged between the tubular nipple and the air guide element. When the bayonet coupling is assembled, this sealing ring exerts an axial biasing force. Thus, not only is the sealing function achieved, but also the components are held in such a manner with respect to each other that there is no play. It is advantageous to clamp the sealing ring between a conically expanding inner surface of the tubular nipple and a radial collar adjoining a cylindrical nozzle of the air guide element. 
     The air guide element is preferably a blown pipe made of synthetic resin material (i.e., plastic) on which the locking element, i.e., the radially extending segments are formed directly from the material of the pipe. The bayonet ring is preferably a high strength injection molded part. To facilitate simple positioning in a defined position, it is advantageous to provide stop abutment elements on the segments and/or the bayonet ring, which stop abutment elements limit the angle of rotation when the bayonet couplings are assembled. In addition, it is advantageous to provide latching elements or detents on the bayonet ring and the air guide element to hold the bayonet ring in the assembled state. 
     In a further embodiment, a guide element, preferably in the form of an O-ring, may be arranged at the front end of the pipe. In this way transmission of vibrations between the front end of the pipe and the tubular nipple of the turbocharger also may be avoided or at least largely damped. In addition, it is advantageous for both the first and the second bayonet coupling to comprise the same number of pairs of segments which form the bayonet couplings. The arrangement of three or four pairs of segments is viewed as particularly suitable. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be described in further detail hereinafter with reference to illustrative preferred embodiments shown in the accompanying drawing figures, in which: 
         FIG. 1  is an exploded representation of a connector for a tubular air guide element according to the present invention; 
         FIG. 2  is a sectional view taken transversely to the longitudinal axis of an air guide element looking in the direction of the bayonet ring; 
         FIG. 3  is a sectional view taken along the line III-III of  FIG. 2 ; 
         FIG. 4  is a representation, according to  FIG. 2 , in the position of the bayonet ring, in which the connecting device is completely mounted, and 
         FIG. 5  is a sectional view taken along the line V-V of  FIG. 4 ; and 
         FIG. 6  is a schematic representation, of a connection connecting a tubular air duct to a turbocharger consistent with the present invention. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       FIG. 1  shows a connection  1  comprising a tubular nipple  2 , which is disposed on a housing of a turbocharger (which is not illustrated), and an air guide element  3 . In the embodiment of  FIG. 1 , the air guide element  3  is comprised of a pipe  4 , which is made of synthetic resin material and is manufactured preferably by a blow molding process. Locking elements  7  are provided on outer surface  6  of the pipe  4  spaced a predetermined distance from the front end  5  of the pipe, which in the illustrated embodiment extend as first segments  8  over a curved section of the respective circumference. These segments  8  thus constitute radially outwardly projecting engaging members, which cooperate with radially inwardly projecting second segments  14  on an inner wall  13  of a bayonet ring  12  to form a bayonet coupling. 
     In addition, the inner wall  13  of the bayonet ring  12  exhibits third segments  15 , which also project radially inwardly and are provided in order to cooperate with fourth segments  16  on the front end of the tubular nipple  2  to form a further bayonet coupling. All of the segments  8 ,  14 ,  15 ,  16  together form the locking element  7 , which is provided for connecting the air guide element  3  to the tubular nipple  2 . As can be seen from the drawing of the bayonet ring  12 , the respective arrangements of the second segments  14  and the third segments  15  are offset relative to each other around the periphery so that a more uniform distribution of force in the bayonet ring  12  is achieved. 
     In the immediate vicinity of the first segments  8 , the pipe  4  has a radial collar  9 , which is adjoined by a section  4 ′ of reduced diameter that extends to the front end  5  of the pipe  4 . On the section  4 ′ is mounted a sealing ring  10  in the form of an O-ring, which rests against the radial collar  9 . This sealing ring  10  is provided in order to interact with a counterpart surface on the tubular nipple  2 . At the front end  5  of the pipe  4  there is another O-ring  11 , which facilitates the insertion of the front end  5  into the tubular nipple  2  and serves additionally to damp the transmission of vibrations between the assembled parts. 
     The outer periphery  17  of the bayonet ring  12  is provided with axially extending ribs  18 , which serve to facilitate gripping by an assembler during the installation of the bayonet ring, i.e., during production of the bayonet coupling. In order to produce the bayonet coupling, the first step is to push the bayonet ring  12  onto the pipe  4 . At the same time the second segments  14  assume an angular position, in which they may be pushed axially through the spaces between the first segments  8  onto the outer surface  6  of the pipe  4 . Then, by rotating the bayonet ring  12  in relation to the pipe  4 , the second segments  14  move behind the first segments  8 . In so doing, the maximum angle of rotation is limited by the stop abutment element  23  on the first segment  8 . Then the front end  5  of the pipe  4  is introduced into the tubular nipple  2 , and in particular until the seal  10  rests against a mating counterpart surface of the tubular nipple  2 . By suitable axial pressure of the pipe  4  in the direction of the tubular nipple  2  and by rotating the arrangement, formed by pipe  4  and bayonet ring  12 , the third segments  15  are moved behind the fourth segments  16 , with the result that an axial clamping occurs during the rotating process due to the contour of the segments  15  and  16 . 
       FIG. 2  is a sectional view of the pipe  4  transversely to the longitudinal axis looking in the direction of the bayonet ring  12 . In  FIG. 2  the shapes on the bayonet ring  12  are somewhat modified, and there are also additional elements, however the principles of construction of this arrangement are comparable to the configuration in  FIG. 1 . A concentric ring  29 , which is linked to the material of the pipe via legs  30 , is formed on the pipe  4 . The concentric ring  29  exhibits three radial projections  31 , which are staggered by 120° and on each of which a respective detent  24  is provided. In the drawing in  FIG. 2 , these detents  24  engage in locking notches  25 ′ on an inner ring  26  of the bayonet ring  12 . The bayonet ring  12  also comprises an outer ring  27 , which is connected to the inner ring  26  by a plurality of legs  28 . The inner ring  26  has three radially inwardly directed stop abutment elements  23 , which serve to limit the angle of rotation through which the bayonet ring  12  may be rotated relative to the pipe  4 . In the vicinity of the stop abutment element  23  there is another locking notch  25 , in which the detent  24  engages, when the bayonet ring  12  is moved into the position in which the projection  31  rests against the stop abutment element  23 , as shown in  FIG. 4 . 
       FIG. 3  is a sectional view taken along the line III-III of  FIG. 2 . This drawing shows the tubular nipple  2  with the adjoining air guide element  3  and the bayonet ring  12 . The air guide element  3  comprises the pipe  4 , which is produced preferably by the blow molding method and on which the concentric ring  29  is formed by way of legs  30 . In the lower region of  FIG. 3  one can see the projection  31  on the concentric ring  29 . In the upper region of  FIG. 3  one can see the stop abutment element  23 , which projects radially inwardly from the inner ring  26 . The inner ring  26 , the outer ring  27  and the legs  28 , which connect the inner and outer rings together, (cf.  FIG. 2 ) form the bayonet ring  12 . On the end facing the pipe  4 , the bayonet ring  12  has radially inwardly extending second segments  14 , which engage the radially outwardly extending first segments  8  on the pipe  4 . On the end facing the tubular nipple  2 , the bayonet ring  12  has the radially inwardly extending third segments  15 , which, like the other segments, also form the locking element  7 . The outer circumference of the tubular nipple  2  carries the fourth segments  16 , which together with the third segments  15  form the first bayonet coupling  21 . 
     The first segments  8  and the second segments  14  together form a second bayonet coupling  20 . The side of the first segments  8  that faces the tubular nipple  2  has a radial collar  9 , in front of which is located a cylindrical nozzle  22 . A sealing ring  10 , which rests against the radial collar  9 , is mounted on the cylindrical nozzle  22 . The tubular nipple  2  has a conically expanding inner surface  19 , against which the sealing ring  10  is clamped. The arrow II matches the view shown in  FIG. 2 . 
       FIG. 4  is a drawing similar to  FIG. 2 . However, in  FIG. 4  the bayonet ring  12  is rotated in relation to the pipe  4  and its concentric ring  29 . It can be seen from this drawing that the projection  31  lies against the stop abutment element  23 ; and in this position the detent  24  engages in the locking notch  25 . Due to the interengagement of the detent  24  with the locking notch  25 , the bayonet ring  12  is secured in its position in relation to the pipe  4 . All other reference numerals correspond to those used for the same parts in  FIG. 2 , so that reference is made here to the respective description of the parts in  FIG. 2 . 
       FIG. 5  is a sectional view taken along line V-V of  FIG. 4 . This drawing shows a connection that is completely assembled. That is, both the first bayonet coupling  20  and the second bayonet coupling  21  are in the totally locked position. The locking element  7  is formed, on the one hand, by the first segments  8  and the second segments  14  and, on the other hand, by the third segments  15  and the fourth segments  16 . Since the bayonet ring  12  straddles both the fist segments  8  and the fourth segments  16 , and it engages with the second segments  14  and the third segments  15 , the pipe  4  is held against the tubular nipple  2  under the prestress generated by compression of the sealing ring  10 . Also, the reference numerals used in  FIG. 5  correspond to those used to identify the same parts in  FIG. 3 . 
       FIG. 6  presents a schematic representation of a connection  1  comprising a tubular nipple  2  disposed on the housing  50  of a turbocharger. 
     Whereas in the embodiment in  FIG. 1 , each of the bayonet couplings, distributed around the circumference, comprises four pairs of segments, in the embodiment shown in  FIGS. 2 to 5 , three segment pairs are provided for each bayonet coupling. 
     The foregoing description and examples have been set forth merely to illustrate the invention and are not intended to be limiting. Since modifications of the described embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed broadly to include all variations within the scope of the appended claims and equivalents thereof.