Patent Document

CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is the U.S. National Phase Application of PCT International Application No. PCT/EP2010/059349, filed Jul. 1, 2010, which claims priority to German Patent Application No. 10 2009 034 626.0, filed Jul. 27, 2009, the contents of such applications being incorporated by reference herein. 
     FIELD OF THE INVENTION 
     The invention relates to an assembly comprising a compensating reservoir and a master cylinder for a hydraulic motor vehicle brake system, wherein the compensating reservoir has two fastening lugs, each with an opening, wherein the openings are in alignment with an opening in the master cylinder, and the compensating reservoir is fastened by way of a releasable connection by means of a fastening pin, which extends through the aligned openings. 
     BACKGROUND OF THE INVENTION 
     An assembly of this kind is known from DE 100 47 325 A1, which is incorporated by reference, for example. The fastening pin known therefrom is provided as an angled pin and has a nose which can be locked in spring strips connected to the fastening lug. The angled pin provided is generally made from stainless steel. Removal from the fastening lugs is accomplished with the aid of a tool, and this is regarded as disadvantageous, especially in view of the ever decreasing amount of installation space for the assembly in the engine compartment. Moreover, the expensive production of the spring strips is regarded as disadvantageous. At the same time, there is the requirement for vehicle components that are optimized in terms of weight. 
     Other ways of fastening the compensating reservoir envisage connecting the compensating reservoir to the master cylinder by means of screws. For this purpose, expensive production of a thread in the master cylinder is required. 
     SUMMARY OF THE INVENTION 
     It is an aim of the invention to provide an assembly comprising a compensating reservoir and a master cylinder which is improved in these respects and, at the same time, has a design which is optimized in terms of weight. 
     According to aspects of the invention, is achieved by virtue of the fact that the fastening pin provided is made of plastic and interacts positively or nonpositively with at least one of the openings in the fastening lugs. As a result, the assembly can be designed for optimum weight while being simple to produce and can be assembled and partially disassembled without tools. 
     To simplify positioning during installation, the fastening pin preferably has a head flange at a first end for the purpose of resting against one of the fastening lugs. It is particularly advantageous here if, where possible, the fastening pin and the fastening lugs are designed in such a way that installation can take place from both sides, i.e. from both fastening lugs. 
     The fastening pin preferably has one or more latching elements, which interacts positively with at least one of the openings. It is advantageous that the latching elements can be provided in a simple manner during the production of the fastening pin. Additional machining is generally unnecessary. 
     An advantageous embodiment of the invention envisages that the openings in the fastening lugs each have a recess on an inner side, into which recess one or more latching noses on the fastening pin engage after the installation thereof. 
     Another advantageous embodiment envisages that the fastening pin has, at the second end thereof, one or more resilient latching arms, which engage on one of the fastening lugs after its installation. 
     It is advantageous here if the latching arms are designed in such a way that they are pressed together resiliently during installation and removal. 
     In another advantageous embodiment, provision is furthermore made for the fastening pin to have resilient spiral latching elements at its second end. 
     In order to prevent rattling of the fastening pin in the opening in the master cylinder, provision can preferably be made for the fastening pin to have means for wedging in the opening in the master cylinder in a central section. 
     An advantageous embodiment envisages that the fastening pin is provided with a convexity in the central section and has an axially oriented slot. 
     Another advantageous embodiment of the invention envisages that the fastening pin has axially oriented projections in the central section. 
     A simple nonpositive connection between the fastening pin and a fastening lug can be achieved if the fastening pin has, at the second end thereof, a thread- or fir tree-shaped profile which can be wedged in the openings in the fastening lugs. 
     According to an advantageous embodiment, the fastening pin can alternatively have, at the second end thereof, a thread- or fir tree-shaped profile which interacts with a complementary profile in the openings in the fastening lugs. 
     The fastening pin provided is preferably made from a harder plastic than the compensating reservoir. It is thereby possible to ensure that the fastening pin is not damaged during its installation and during its possible removal. 
     An advantageous embodiment envisages that the fastening pin provided is made from glass-reinforced polyamide. However, other plastics materials can also be used within the scope of the invention. 
     The above aspect is furthermore achieved by virtue of the fact that the fastening pin has, at a first end, a head flange for the purpose of resting against one of the fastening lugs, and, on the head flange, has two resilient projections, which engage in recesses on an outer side of the fastening lugs after installation. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention is best understood from the following detailed description when read in connection with the accompanying drawings. Included in the drawings is the following figures: 
         FIG. 1  shows a detail of an assembly according to aspects of the invention of a first illustrative embodiment comprising a compensating reservoir and a master cylinder; 
         FIG. 2  shows a detail of an assembly according to aspects of the invention of a second illustrative embodiment comprising a compensating reservoir and a master cylinder; 
         FIG. 3  shows a detail of an assembly according to aspects of the invention of a third illustrative embodiment comprising a compensating reservoir and a master cylinder; 
         FIG. 4  shows a detail of an assembly according to aspects of the invention of a fourth illustrative embodiment comprising a compensating reservoir and a master cylinder; 
         FIG. 5  shows a fastening pin of an assembly according to aspects of the invention of a fifth illustrative embodiment comprising a compensating reservoir and a master cylinder; 
         FIG. 6  shows the fastening pin according to  FIG. 5  in a front view; 
         FIG. 7  shows a detail of an assembly according to aspects of the invention of a sixth illustrative embodiment comprising a compensating reservoir and a master cylinder; 
         FIG. 8  shows a fastening pin of an assembly according to aspects of the invention of a seventh illustrative embodiment comprising a compensating reservoir and a master cylinder; 
         FIG. 9  shows a fastening pin of an assembly according to aspects of the invention of an eighth illustrative embodiment comprising a compensating reservoir and a master cylinder, and 
         FIG. 10  shows a fastening pin of an assembly according to aspects of the invention of a ninth illustrative embodiment comprising a compensating reservoir and a master cylinder. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       FIGS. 1 to 10  show schematically illustrative embodiments of an assembly according to aspects of the invention comprising a compensating reservoir  1  and a master cylinder  2  for a hydraulic motor vehicle brake system, the construction and operation of which are fundamentally known. After the mounting of the compensating reservoir  1  on the master cylinder  2 , connection stubs (not shown) of said reservoir are accommodated in corresponding connection openings of the master cylinder  2  and connect pressure medium chambers of the compensating reservoir  1  to pressure spaces of the master cylinder  2  in a known manner. 
     For releasable connection to the master cylinder  2 , the compensating reservoir  1  has two fastening lugs  3 ,  4 , each with an opening  5 ,  6 . After the mounting of the compensating reservoir  1  on the master cylinder  2 , these openings  5 ,  6  are in alignment with an opening  7  in the master cylinder  2 . For fastening, a fastening pin  9 ,  10 ,  11 ,  12 ,  13 ,  14 ,  15 ,  16 ,  36  made of plastic is provided, which extends through the aligned openings  5 ,  6 ,  7 . In the region of a master cylinder lug  8 , the opening  7  in the master cylinder  2  is provided as a through hole, which extends between reservoir connections (not shown) of the master cylinder  2 . 
     Common to all the illustrative embodiments described below is the fact that the fastening pin  9 ,  10 ,  11 ,  12 ,  13 ,  14 ,  15 ,  16 ,  36  provided is made from a harder plastic than the compensating reservoir  1 . It is thereby possible to ensure that the fastening pin  9  to  16  is not damaged during its installation and during its possible removal. For example, the fastening pin  9  to  16 ,  36  provided can be made from glass-reinforced polyamide, although other plastics materials can also be used within the scope of the invention. 
     In order to simplify the installation of the fastening pin  9  to  16  and to make it possible without the aid of tools and to obtain an assembly which is optimized in terms of weight, the fastening pin  9  to  16 ,  36  provided in the respective illustrative embodiment is made of plastic and interacts positively or nonpositively with at least one of the openings  5 ,  6  in the fastening lugs  3 ,  4  and with the fastening lugs  3 ,  4 . 
     To simplify positioning during installation, the fastening pin  9  to  16 ,  36  has a head flange  18 ,  38  at a first end  17 ,  37  for the purpose of resting against one of the fastening lugs  3 ,  4 . It is particularly advantageous here if, where possible, the fastening pin  9  to  16 ,  36  and the fastening lugs  3 ,  4  are designed in such a way that installation can take place from both sides, i.e. from both fastening lugs  3 ,  4 . 
       FIGS. 1 to 6  show five illustrative embodiments in which the fastening pin  9  to  13  has one or more latching elements, which interacts positively with at least one of the openings  5 ,  6  in the fastening lugs  3 ,  4 . The latching elements can be provided in a simple manner during the production of the fastening pin  9  to  13 , thereby making it possible to omit additional machining. 
       FIG. 1  shows a detail of an assembly according to aspects of the invention of a first illustrative embodiment. As can be seen, the openings  5 ,  6  in the fastening lugs  3 ,  4  each have a recess  19 ,  20  on an inner side, with the result that the openings  5 ,  6  are of stepped design, with a small diameter on an outer side and a large diameter on the inner side. The fastening pin  9  has a plurality of latching noses  21 , which engage in the recess  19  after the installation thereof. The latching noses  21  are dimensioned in such a way that they can be deformed during installation through the opening  5 . 
     Since both fastening lugs  3  and  4  each have a stepped opening  5 ,  6  with the same diameters, installation from both sides is possible. 
       FIGS. 2 to 4  show illustrative embodiments in which the fastening pins  10  to  12  have, at the second ends  27  thereof, one or more resilient latching arms  22  to  24 , which can engage on the fastening lug  3 ,  4  after the installation of the fastening pins  10  to  12 . 
       FIG. 2  shows a second embodiment. The fastening pin  10  has two latching arms  22 , which are advantageously pressed together resiliently during installation and during removal. For this purpose, the latching arms  22  are arranged substantially in a U shape, and the latching arms  22  each have two guide bevels  25 ,  26 . As is apparent from  FIG. 2 , the guide bevels  25  allow the latching arms  22  to be pressed together during the installation of the fastening pin  10 , and the guide bevels  26  allow them to be pressed together during the removal thereof. 
     As can be seen from  FIGS. 3 and 4 , the latching arms  23 ,  24  of the third and fourth illustrative embodiments are dimensioned in such a way that the fastening pin  11 ,  12  does not have a larger diameter in the region of the latching arms  23 ,  24  if the latching arms  23 ,  24  are pressed together during installation. Owing to the design of the latching arms  23 ,  24 , the fastening pins  11 ,  12  cannot be removed. 
       FIGS. 5 and 6  show a fifth illustrative embodiment, the fastening pin  13  of which has resilient spiral latching elements  28  at its second end  27 , with a diameter of the end  27  being smaller than a diameter of the opening  7  in the master cylinder  2  in order to ensure simple installation of the fastening pin  13 . 
     In order to prevent rattling of the fastening pins  9  to  13  of the illustrative embodiments under consideration in the opening  7  in the master cylinder  2 , provision can be made in these for the fastening pins  9  to  13  to have means for wedging in the opening  7  in a central section  29 . These means can be axially oriented projections  30 , for example, as illustrated in  FIG. 2 . 
     As an alternative, the fastening pins  9  to  13  can be provided with a convexity, i.e. can be arched, in the central section  29 . In this case, an axially oriented slot allows simple installation through the opening  7  in the master cylinder  2 . 
     A sixth illustrative embodiment in accordance with  FIG. 7  provides a nonpositive connection between the fastening pin  14  and a fastening lug  3 ,  4 , which can be achieved in a simple manner if the fastening pin  14  has, at the second end  27  thereof, a thread- or fir tree-shaped profile  31  which can be wedged in the opening  5 ,  6 . 
     According to  FIGS. 8 and 9 , which show a seventh and eighth illustrative embodiment, the fastening pin  15 ,  16  can have, at the second end  27  thereof, a thread- or fir tree-shaped profile  32 ,  33  which interacts with a complementary profile  34 ,  35  in the opening  6  in the fastening lug  4 . 
     A ninth illustrative embodiment is shown in  FIG. 10 . The fastening pin  36  likewise has, at a first end  37 , a head flange  38  for the purpose of resting against one of the fastening lugs  3 ,  4 . In contrast to the illustrative embodiments described above, however, the head flange  38  has two resilient projections  39 , which engage positively in recesses  40 ,  41  on an outer side of the fastening lugs  3 ,  4  after installation. Since the recesses  40 ,  41  are provided on both fastening lugs  3 ,  4 , installation can take place from both sides. 
     Installation from both sides is advantageously possible if the openings  5 ,  6  have an identical diameter. For this purpose, the fastening pin  10  illustrated in  FIG. 2  has a uniform diameter in the region of the openings  5 ,  6 , for example. Stepping of the fastening pin  10 ,  11 ,  12 ,  14 ,  15 ,  16  after the head flange  18 , as illustrated, is thus not absolutely essential. 
     LIST OF REFERENCE SIGNS 
     
         
           1  compensating reservoir 
           2  master cylinder 
           3  fastening lug 
           4  fastening lug 
           5  opening 
           6  opening 
           7  opening 
           8  master cylinder lug 
           9  fastening pin 
           10  fastening pin 
           11  fastening pin 
           12  fastening pin 
           13  fastening pin 
           14  fastening pin 
           15  fastening pin 
           16  fastening pin 
           17  end 
           18  head flange 
           19  recess 
           20  recess 
           21  latching nose 
           22  latching arm 
           23  latching arm 
           24  latching arm 
           25  guide bevel 
           26  guide bevel 
           27  end 
           28  latching element 
           29  section 
           30  projection 
           31  profile 
           32  profile 
           33  profile 
           34  profile 
           35  profile 
           36  fastening pin 
           37  end 
           38  head flange 
           39  projection 
           40  recess 
           41  recess

Technology Category: 2