Abstract:
A device for mounting a part to a body of a motor vehicle. A positioning mechanism positions the part in relation to the body in a determined fixing position, which is geometrically defined in a reference trihedral formed by the longitudinal axis X, the transverse axis Y, and the vertical axis Z of the body. The positioning mechanism includes a temporary mounting structure including a first mechanism mounting the structure to the body in a given use position in which a second mechanism belonging to the structure cooperates with the part to position the part in relation to the body in the above-mentioned determined fixing position, which is defined by a given positioning reference system corresponding to the use position of the structure on the body.

Description:
BACKGROUND 
     The invention relates to a device for mounting a part on the body of a motor vehicle. 
     The invention relates more particularly to a device for mounting a part, such as a support for mounting a bodywork element, on the body of a motor vehicle, of the type comprising means for positioning the part relative to the body in a determined position, called the fastening position, that is defined geometrically in a reference trihedron (X, Y, Z) formed by the longitudinal axis X, the transverse axis Y and the vertical axis Z of the body, so as to proceed in particular to fasten the part, thus positioned, on the body of the vehicle. 
     Many devices of this type are known that are used at the stations of an assembly line designed for the manufacture of the vehicle in order to carry out there the mounting of various parts on the body of a vehicle, such as supports, bodywork elements or opening elements. 
     To do this, automated devices are usually used comprising in particular very complex tools such as robotic arms that are mounted so as to be movable in order to carry out assemblies “on the move”, that is to say that are capable of moving along the assembly line at the same time as the body. 
     Such mounting devices are for example capable of picking up a part thanks to gripping means of the sucker type from a storage station and of positioning this part relative to the body in a determined geometric position that is defined relative to the body in order to fasten the part to the body. 
     Specifically, in the case of mounting a part, such as a bodywork element support, it is first positioned relative to the body and then it is fastened to the body by means of appropriate conventional fastening means. 
     In the case of a supporting part for a bodywork element, it is imperative to control with precision and repetitively the correct positioning of the part to be fastened to the body since that also determines the positioning of the bodywork element that will be mounted later. 
     Therefore, precision in the positioning of the supporting part during mounting and in fastening makes it possible to ensure that a good quality of assembly of the elements is obtained, in particular their positioning flush with one another in the case of a bodywork element such as a side wing or else an engine hood. 
     The mounting devices according to the prior art require many controls, often complex to study and design, that require considerable perfection time on the assembly line. 
     In addition, although having autonomous operation, such devices require regular maintenance operations that then cause stoppages of the station, and even of the assembly line, which are damaging in terms of productivity and are therefore particularly costly. 
     In addition, each device is usually, from its conception, dedicated to mounting a particular part at a given station on a determined assembly line so the devices can be readapted little or not at all to new stations of new lines designed in particular for the production of a new vehicle. 
     Consequently, the devices comprising positioning means that are known in the prior art are not fully satisfactory. 
     BRIEF SUMMARY 
     The object of the invention is to propose a device for mounting a part on the body comprising positioning means that are particularly economical, reliable, flexible to use and easy to apply. 
     For this purpose, the invention proposes a device for mounting a part on the body of a motor vehicle of the type described above, characterized in that the positioning means comprise a provisional mounting structure comprising first means for mounting the structure on the body in a given position of use in which second means of the structure interact with the part in order to position it relative to the body in said determined fastening position which is defined according to a given positioning reference system (X′, Y′, Z′) corresponding to the position of use of the structure on the body. 
     Thanks to the invention, the positioning means are capable of being easily and rapidly applied, in particular during the beginning of production of a new vehicle, and guarantee a mounting quality and reliability irrespective of the types of parts, particularly the supports of front side wings or the hinges of the engine hood. 
     According to other features of the invention:
         the first means comprise temporary means for coupling the structure to the body so as to position the structure relative to the body according to at least a first of the three axes of the positioning reference system (X′, Y′, Z′) such as the vertical axis Z′, which determines the position of fastening of the part relative to the reference trihedron (X, Y, Z) of the body;   the coupling means consist of pins that are received in matching holes of the body;   at least one of the coupling pins comprises means for transverse abutment of the structure relative to the body;   the first means comprise locking means for immobilizing the structure on the body according to at least a last X′ and/or Y′ of the three axes of said positioning reference system (X′, Y′, Z′);   the locking means comprise first means for locking the structure in the position of use on the body that are mounted so as to be able to rotate between:
           a rest position in which the means are positioned so as not to interfere with the body when the structure is mounted on the body, and   a locked position in which the means are positioned so as to immobilize the structure relative to the body along the transverse axis Y′;   
           the locking means comprise second means for locking the structure in the position of use on the body that are mounted so as to be able to move in translation between:
           a rest position in which the second means enter, with clearance, matching orifices of the body, and   a locked position in which the second means interact with the body so as to immobilize the structure relative to the body along the longitudinal axis X′;   
           the second means of the structure comprise centering means so as to position the part relative to the body in the determined fastening position;   the part thus positioned is fastened to the body by means of fastening means;   the structure is made of light and strong material, such as carbon fiber.       

    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Other features and advantages of the invention will appear on reading the following detailed description for the understanding of which reference will be made to the appended figures amongst which: 
         FIG. 1  is a schematic side view that represents, as an exploded view before assembly, the provisional mounting structure according to the invention that is designed to position the part consisting of the wing support mounted on the body of the vehicle; 
         FIG. 2  is a schematic view that represents the mounting structure of  FIG. 1  mounted in the position of use on the body. 
     
    
    
     DETAILED DESCRIPTION 
     In the description and the claims, expressions such as “rear” and “front”, “left” and “right”, or “top” and “bottom” and the orientations “longitudinal”, “transverse” and “vertical” will be used in a nonlimiting manner with reference to the trihedron (X, Y, Z) represented in the figures and to the definitions given in the description. 
     In addition, identical, similar or analogous elements of the invention will be indicated by the same reference numbers. 
     Partially represented in  FIG. 1 , in side view, is a body  10  of a motor vehicle  12  during manufacture on an assembly line (not shown), that is to say essentially the front longitudinal portion of the body  10 . 
     Various parts are mounted on the front portion of the body  10 , particularly the engine hood  14  that is mounted on the body by means of two hinges  16 , side wings or else the front face of the vehicle  12 . 
     In a known manner, the hood  14  is mounted so as to be movable between a closed operating position in which it extends generally horizontally as illustrated in  FIG. 1  and an open position in which it allows access to the engine. 
     As a nonlimiting example, the following description will describe the use of a device  18  comprising positioning means  20  according to the invention for mounting a part forming a support for mounting a bodywork element (not shown), more precisely here a support  22  designed to allow the mounting and/or fastening of the left side wing (not shown) of the bodywork of the vehicle  12 . 
     The device  18  for mounting the support  22  on the body  10  of the motor vehicle  12  is of the type comprising means  20  for positioning the support  22  relative to the body  10  in a determined position, called the fastening position, which is defined geometrically in a reference trihedron (X, Y, Z) formed by the longitudinal axis X, the transverse axis Y and the vertical axis Z of the body  10 . 
     The positioning means  20  therefore make it possible in particular to position the support  22  relative to the body  10  in order to fasten the support  22 , thus correctly positioned, to the body  10 . 
     According to the invention, the positioning means  20  comprise a provisional mounting structure  24  comprising first means  26  for mounting the structure  24  on the body  10  in a given position of use in which second means  28  of the structure  24  interact with the support  22  in order to position it relative to the body  10  in said determined fastening position which is defined according to a given positioning reference system (X′, Y′, Z′). 
     The first means  26  comprise temporary means  30  for coupling the structure  24  to the body  10  so as to position the structure  24  relative to the body  10  according to at least a first of the three axes of the positioning reference system (X′, Y′, Z′), here the vertical axis Z′, which determines the fastening position of the support  22  relative to the reference trihedron (X, Y, Z) of the body  10 . 
     As a variant, the means  30  for coupling the structure  24  to the body  10  position the structure  24  along the longitudinal axis X′ and the vertical axis Z′ corresponding to its position of use. 
     Preferably, the coupling means  30  consist of pins, here a front pin  32  and a rear pin  34 , which extend from the structure  24  transversely to the right, that is to say to the body  10  which comprises matching holes in which the pins  32 ,  34  are received. 
     In the mounted position, the front pin  32  and the rear pin  34  thus enter respectively a front hole  36  and a rear hole  38  in the body  10 . 
     Advantageously, at least one pin  34  of the coupling pins  32 ,  34  comprises means, such as an annular collar  40 , forming a transverse abutment of the structure  24  relative to the body  10 . 
     The first means  26  comprise locking means  42  capable of immobilizing the structure  24  on the body  10  along at least a last axis X′ of the three axes of said positioning reference system (X′, Y′, X′), advantageously along the longitudinal axis X′ and the transverse axis Y′. 
     More precisely, the locking means  42  comprise first locking means, such as a locking finger  44 , for locking the structure  24  in the position of use on the body  10  along the transverse axis Y′. 
     The locking finger  44  is arranged substantially in the center of the structure  24  and it is mounted so as to be movable between:
         a rest position in which the finger  44  extends generally longitudinally so as not to interfere with the body  10  when the structure  24  is mounted on the body, and   a locked position in which the finger  44  extends generally vertically so as to press against the inner vertical face of the body  10  to immobilize the structure  24  relative to the body  10  along the transverse axis Y′.       

     Advantageously, the locking finger  44  is mounted so as to be able to rotate about a substantially transverse axis A and it is operated between its extreme rest and locked positions by means of an operating means, here a handle  46  that is able to be actuated manually by an operator. 
     The locking means  42  also comprise second means  48  for locking the structure  24  in the position of use on the body  10 , such as locking spigots. 
     Preferably, the structure  24  comprises a front locking spigot  50  and a rear locking spigot  52  that are received, in the mounted position, in matching orifices respectively  54  and  56  in the body  10 . 
     The locking spigots  50 ,  52  are mounted so as to be movable and are operated in movement by means of the handle  46 , that is advantageously at the same time as the transverse locking finger  44  of the structure  24 . 
     The locking spigots  50 ,  52  are mounted so as to be movable in translation in the longitudinal direction between:
         a rest position in which each spigot  50 ,  52  enters, with clearance, a matching orifice  54 ,  56  of the body  10 , and   a locked position in which each spigot  50 ,  52  interacts with a portion of the edge  58  delimiting the orifice  54 ,  56  of the body  10  so as to immobilize the structure  24  relative to the body  10  along the longitudinal axis X′.       

     The support  22  is illustrated here directly mounted on the body  10  relative to which it will then be positioned in its determined fastening position by means of the device  18  when the latter is mounted on the body  10  and positioned in its position of use. 
     As can be seen in  FIG. 1 , the support  22  is mounted pressing against a top longitudinal edge  58  of the body  10  and against an upright edge  60 . 
     As a variant, the support  22  is first mounted on the device  18  and the subassembly thus formed is then mounted on the body  10 . 
     The position of use of the structure  24  on the body  10  therefore corresponds here to the position obtained according to the reference trihedron (X, Y, Z) after actuation of the locking means to immobilize the structure  24  and the support  22  relative to the body  10 . 
     Advantageously, the second means  28  of the structure  24  comprise centering means, such as a locator  62 , that is received in a matching hole  64  of the support  22  so as to position the support  22  relative to the body  10  along the axes X, Y, Z in the determined fastening position. 
     The successive operating operations of the mounting structure  24  of the device  18  will now be described in greater detail. 
     As can be seen in  FIG. 1 , the support  22  having first been mounted on the body  10 , the structure  24  is then mounted on the body  10 . 
     To do this, the structure  24  is mounted in a transverse movement in the direction of the body  10 , along the dot-and-dash lines shown in  FIG. 1 , so as to insert respectively the front pin  32  and rear pin  34  in the front hole  36  and rear hole  38 , and the front locking spigot  50  and rear locking spigot  52  in the matching orifices  54  and  56 . 
     In addition, the locator  62  of the structure  24  is inserted into the matching hole  64  of the support  22  so that the support  22  is then linked in movement to the structure  24 . 
     After it has been mounted, the structure  24  is in the position illustrated in  FIG. 2 . 
     As explained above, the structure  24  is not yet positioned in the position of use that is reached only after the actuation of the locking means  42  to immobilize the structure  24 . 
     Specifically, before it is immobilized, the structure  24 , although mounted onto the body  10 , is capable of moving along at least one or two axes X′ and Y′ of the given positioning reference system (X′, Y′, Z′). 
     The structure  24  being in the mounted position illustrated in  FIG. 2 , the handle  46  is then actuated to operate the movement of the locking finger  44  and of the locking spigots  50  and  52  from their rest position to their locked position. 
     The handle  46  is for example rotated a quarter-turn in the direction of the arrow F which simultaneously causes, on the one hand, the rotational movement of the locking finger  44  which presses against the inner vertical face of the body  10  and, on the other hand, the movement in translation of each of the locking spigots  50 ,  52  in the direction of the transverse axis A. 
     The locking finger  44  positions the structure  24  in its position of use along the transverse axis Y′, the annular abutment collar  40  advantageously pressing against the facing surface of the body  10  that is adjacent to the hole  38 . 
     The locking spigots  50  and  52  move in opposite directions toward one another until each of the spigots interacts with a portion of the edge of the hole  54 ,  56  to position the structure  24  along the axis X′. 
     The structure  24  is consequently immobilized in its position of use and the support  22  is automatically in its determined fastening position. 
     Consequently, the support  22  thus correctly positioned is able to be fixedly fastened to the body  10  by means of fastening means, such as screws. 
     The fastening means comprise for example two first screws  66  that are received transversely in matching holes  68  of the support  22  and of the body  10 , and a second screw  70  that is received vertically in a matching hole  72 . 
     The second screw  70  is arranged at the longitudinal front end of the support  22  while the first screws  66  are situated on the rear longitudinal portion. 
     The support  22  being fastened to the body  10  and being correctly positioned, the handle  46  is operated in the opposite direction to move the locking means  42  into the rest position and remove the structure  24  which may then be used to repeat the operation of mounting a support  22  on the next vehicle  12 . 
     Advantageously, the provisional mounting structure  24  is made of a strong and light material, such as carbon fiber or similar material, so as to be easily handled by an operator while allowing compliance with assembly rates. 
     The device  18  for mounting the part  22  according to the invention is therefore particularly flexible to use particularly in that it does not require any long and costly perfecting. 
     Consequently, the provisional mounting structure  24  allows an extremely appreciable time-saving, in particular when starting a new assembly line and requires no maintenance operation. 
     Advantageously, the mounting structure is able to be used by an operator in a manner totally independent of the other stations on the assembly line. 
     Naturally, the mounting of the wing support  22  is only one nonlimiting example of a part able to be positioned thanks to the structure  24  according to the invention.