Abstract:
A method for manufacturing an automotive mirror, in particular a side mirror, includes forming a printed circuit board as flexible printed circuit board with n+1 branches, nεN, providing n modules each including at least one electronic element housed within a plastic casting and connected to conducting paths on at least one of the surfaces of the plastic casting, and at least one standard gripping point, guiding structure, snap connection element and/or sealing member provided by the plastic casting, connecting up to n of said branches to one module each and connecting one branch to cables or a cable harness to be connected to a power supply and/or a control unit outside the mirror, providing mirror parts free of electronic elements, and assembling the mirror parts and the modules.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a national stage entry of International Patent Application No. PCT/IB2015/059419, filed Dec. 5, 2014, which claims the benefit of foreign priority to European Patent Application No. 14196582.2, filed Dec. 5, 2014, and European Patent Application No. 15162850.0, filed Apr. 8, 2015, each of which is incorporated herein by reference in its entirety for all purposes. 
     
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0002]    Not applicable. 
       REFERENCE TO A COMPACT DISK APPENDIX 
       [0003]    Not applicable. 
       BACKGROUND 
     1. Field 
       [0004]    The following description relates to a method for manufacturing an automotive mirror. 
       2. Description of Related Art 
       [0005]    Typically, the assembling of automotive mirrors, like side mirrors, is mostly done manually by human beings within a manufacturing unit. This leads to high costs and is time consuming. Therefore there is the need for providing automotive mirror parts suited for an automated robotic assembly line. 
         [0006]    A gripping device for articles like motor vehicle headlights is known e.g. from DE 10 2005 062 706 A1. The known device has gripping units which exert gripping forces perpendicular to individual points of surfaces of such articles. Each gripping unit grips an article at one gripping point such that the article can be hold by the device. This allows for gripping of geometrically different articles of similar upper surface topology with the same device; but the gripping device is rather complicated and not suited for different surface topologies. 
         [0007]    As mirror parts of an automotive side mirror like a housing part, a lighting module or a circuit board can have a large variety of geometries and/or topologies, even differing from model to model, presently most of the mirror parts are gripped in different manners with specific gripper designs. This requires time consuming and cost intensive gripper changes. 
         [0008]    In order to provide a high degree of freedom, flexible circuit boards are used in automotive mirrors, see for example DE 10 2004 025 385. Such flexible circuit boards or wire harnesses provide terminals to be connected to different kinds of modules, like a blind spotter module, a ground light module and a turn signal module. The respective connection between the terminals and the modules and the subsequent attachment of the modules might even require assembling steps with gripper movements in different directions. 
         [0009]    Molded Interconnect Devices (MID), which are plastic components containing electric printed circuit boards and functioning as 3 dimensional printed circuit boards, are in particular used in the automotive industry. Via Laser Direct Structuring (LDS) such electric printed circuit boards can for example be applied to plastic castings. 
       SUMMARY 
       [0010]    It is the object of the present invention to provide an improved method for manufacturing an automotive mirror. 
         [0011]    In an aspect, a method for manufacturing an automotive mirror, in particular a side mirror, includes: forming a printed circuit board as flexible printed circuit board with n+1 branches, nεN, providing n modules each including at least one electronic element housed within a plastic casting and connected to conducting paths on at least one of the surfaces of the plastic casting, and at least one standard gripping point, guiding structure, snap connection element and/or sealing member provided by the plastic casting, connecting up to n of said branches to one module each and 
         [0000]    connecting one branch to cables or a cable harness to be connected to a power supply and/or a control unit outside the mirror, providing mirror parts free of electronic elements, and assembling the mirror parts and the modules. 
         [0012]    It is preferred that the printed circuit board and the modules are connected to form a pre-assembled unit, and/or either the mirror parts and the modules or the pre-assembled unit are assembled by snap connections together with the mirror parts. 
         [0013]    It is also proposed that each module is formed as a molded interconnect device (MID) providing the plastic casting with the conducting paths, with the MID preferably being a metalized two component injection molding, an injection molding with an impressed metal foil or a laser structured injection molding. 
         [0014]    The plastic casting of each module may also be molded with the standard gripping point, in particular provided in an edge region, the guiding structure, in particular provided by a tapering, the snap connection element, in particular provided by a hook or recess, and/or the sealing member, in particular provided by a deformable projection. 
         [0015]    Further, it is proposed that at last one of the modules is connected to a mirror part provided with a structure mating the guiding structure, the snap connection element and/or the sealing member of the module, respectively. 
         [0016]    At least one of the modules may also include a lightning unit, preferably to function as a turn signal module, a blind spot warning module, a logo lamp unit, an environment illuminating unit or the like, or a motor, in particular for a mirror glass adjustment, or a sensor, in particular in form of a camera or radar sensor. 
         [0017]    The method may also include providing at least some of the mirror parts and/or the flexible printed circuit board with at least one standard gripping point. 
         [0018]    The method may also include providing a gripping device with at least one gripping unit designed for gripping the mirror parts, the modules and/or the flexible printed circuit board at the standard gripping points, and assembling the parts by controlling the gripping device. 
         [0019]    It is further proposed that the standard gripping points may be provided by slots, cut outs, recesses, clips, straps, edges and/or projections, and/or the standard gripping points are introduced within the mirror parts, the modules and/or the flexible printed circuit board during manufacture thereof, and/or the standard gripping points are formed with a shape and/or dimension depending from the gripping unit design. 
         [0020]    In addition, it is proposed that a gripping unit design may define the standard gripping points, and the mirror parts, the modules and/or the flexible printed circuit board are formed with the defined standard gripping points. 
         [0021]    At least one structural feature of at least one of the modules, the flexible printed circuit board and/or the mirror parts fulfilling a separate function may be selected to provide at least one standard gripping point, and the gripping unit design and/or control is defined by the structural feature. 
         [0022]    The separate function may be defined by a snap connection element for a mechanical connection or a terminal for an electrical connection. 
         [0023]    The gripping device may be introduced into a production line, and/or the gripping device is integrated into an industrial robot as an end effector tool or is connected to an industrial robot via an automatic tool changer system. 
         [0024]    The gripping device may be formed with a plurality of gripping units which are moved in different directions during the assembling, and/or the gripping device is operated by controlling motors, pneumatic systems and/or hydraulic systems, preferably in reaction to sensor output signals. 
         [0025]    The gripping units may be moveable relative to each other and/or all together, each gripping unit may include a pair of 2 fingers for gripping one mirror part, one module or the flexible printed circuit board and an arm for moving said pair of 2 fingers. 
         [0026]    It is also proposed that the fingers of each pair are moveable and/or cooperate with an ejection means for ejecting the part, the module or the flexible printed circuit board gripped by the respective pair of fingers. 
         [0027]    In addition, the gripping units may be attached to a center spine, and the spine may be controlled to conduct a rotary and/or translatory movement via a center spine placing means. 
         [0028]    Each gripping arm may include an upper arm and a lower arm, with the upper arm being moveable relative to the lower arm, and/or the upper arm being pivotable or rotatable relative to the lower arm with at least one axis of rotation via arm bending means. 
         [0029]    Each pair of fingers may be designed to grip a branch of a flexible circuit board. 
         [0030]    A control unit may cooperate with the gripping device, the tool connecting means, the center spine placing means, the arm bending means and/or the ejecting means, during an assembly the automotive mirror. 
         [0031]    The control unit may receive signals from at least one sensor provided by the gripping device and/or at least one stopper. 
         [0032]    The gripping device may electrically connect the flexible printed circuit board with the modules, preferably by crimping. 
         [0033]    According to a first aspect of the invention the same is based on a modification of individual mirror parts, modules and/or printed circuit boards in order to make them suitable for handling during an automated assembling of an automotive mirror within a manufacturing unit, namely such that any type of common basic gripper instead of several different grippers for handling mirror parts, modules and/or printed circuit board with different designs and thus different geometries and/or topologies can be used. The modification is to provide standard gripping points. Such standard gripping points can be provided by slots, cut outs, recesses, clips, straps and/or projections and can be introduced at any available area e.g. within the individual mirror parts with a shape (like square, rectangular, triangular, circular, hexagonal, octagonal or pentagonal) and dimension adapted to the gripper design or vice versa. As soon as a common gripper design has been selected, pre-defined gripping points can be introduced on e.g. the mirror parts such that they can be assembled by a robot or automated. This reduces the overall costs involved in setting up a production line. In long term it also helps reducing the overall maintenance costs of the production line and also reduces the overall production cycle time and assembling time involved. Using standard gripping points on individual automotive mirror part, modules and/or printed circuit boards also enables a handling of these parts in any orientation or method by a robotic gripping device. 
         [0034]    The slots, cut outs, recesses, clips, straps and/or projections providing the standard gripping points can fulfill an additional function like enabling a snap connection or can be provided by a functional member like a snap-in clips or even two terminals serving an electrical connection between a circuit board and an electric module like a lightning module. 
         [0035]    According to a second aspect of the invention, during an automated assembling of an automotive mirror within a manufacturing unit a robotic gripping device is used which is in particular suited for handling mirror parts during the assembly of an automotive mirror, even in form of a flexible circuit board with e.g. n branches for connecting n electric modules to a power source, n being a member of the natural numbers above 1. Such a gripping device is provided with n gripping units each having one arm arranged around a central spine, each arm having a pair of 2 fingers, with the spine, the arms as well as the fingers being operated pneumatically, hydraulically and/or electrically for handling e.g. the n branches of a flexible circuit board, wire harnesses, mirror parts or any other applicable objects. Thus the gripping device can be operated by supplying for example air, oil, water or electrical current. 
         [0036]    In case the spine has 2 degrees of freedom, namely for 1 translatory and 1 rotary movement, each arm is provided with 2 parts providing at least 1 further degree of freedom and each pair of fingers is provided with at least 1 additional degree of freedom, the gripping device is suited for ample assembly steps, even in different production directions. Thus, the gripping device is a multi operational gripper which can be used for different applications. By varying the features of the gripping units and by adjusting the position of the arms or fingers thereof, even more applications become possible. 
         [0037]    The gripping device is designed based on the idea to benefit from a combination of the advantages of spider legs and a human palm with fingers and, therefore, is called spider gripper in the following. 
         [0038]    The spider gripper can be directly integrated as an end effector tool to an industrial robot or to any type of machinery, but can also be used with an industrial robot or machinery via an automatic tool changer system where the tool side of the respective automatic tool changer module will be connected to the spider gripper top. 
         [0039]    The preferred spider gripper has 6 arms and 6 pairs of fingers which are in particular designed for each holding a branch of a flexible circuit board. Each free end of an arm of the spider gripper has a small pneumatic or hydraulic cylinder or electrically operated motor based system for gripping one branch, inserting the terminals or connectors of said branch in corresponding sockets provided by an electric module and ejecting the branch at the end. 
         [0040]    The number of arms and/or fingers of the spider gripper can be increased or decreased based on the design of the article to be handled, like the design of wire harnesses, and depending on the number of branches of involved flexible circuit boards. The position of the arms and fingers of the spider gripper relative to the central spine and/or relative to each other can be manually or pneumatically, hydraulically and/or electrically adjusted based on the handled articles. 
         [0041]    The spider gripper spine, arms and fingers can be controlled individually. Sensors and mechanical stoppers can be used in the spider gripper for controlling the movement in particular of the individual arms and/or fingers. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0042]    The invention, together with further objects and advantages, may be best understood, by example, with reference to the following description of embodiments taken together with the accompanying schematic drawings: 
           [0043]      FIG. 1A  shows a perspective view of a flexible circuit board without an electrical module of the invention being connected. 
           [0044]      FIG. 1B  shows an enlargement of one of the branches of the flexible circuit board of  FIG. 1 a    with a connected electrical module. 
           [0045]      FIG. 2A  shows a perspective view of a housing part and a second mirror part in form of a light guide unit prior to assembly. 
           [0046]      FIG. 2B  shows an enlargement of the first mirror part in form of a housing part and the light guide unit of  FIG. 2A  after assembly and a turn signal module during assembly. 
           [0047]      FIG. 3A  shows a perspective view of a first mirror part in form of a housing ring with first gripping points provided by straps. 
           [0048]      FIG. 3B  shows the third mirror part of  FIG. 3A  gripped by a gripping unit at third gripping points. 
           [0049]      FIG. 4A  shows a perspective view of a fourth mirror part in form of a top cap with fourth gripping points provided by clips. 
           [0050]      FIG. 4B  shows an enlargement of one of the clips of  FIG. 4A  with recesses. 
           [0051]      FIG. 4C  shows the fourth mirror part of  FIGS. 4A and 4B  gripped by the gripping unit at fourth gripping points. 
           [0052]      FIG. 5A  shows a perspective view of a fifth mirror part in form of a mirror foot with fifth gripping points provided by cut outs. 
           [0053]      FIG. 5B  shows the fifth mirror part of  FIG. 5A  gripped by the gripping unit at the fifth gripping points. 
           [0054]      FIG. 6A  shows a perspective view of an alternative gripping device. 
           [0055]      FIG. 6B  shows an enlargement of one of the gripping units of the gripping device of  FIG. 6A . 
       
    
    
     DETAILED DESCRIPTION 
       [0056]    An automotive side mirror includes a plurality of parts, like a flexible printed circuit board (FPC) shown in  FIGS. 1A and 1B  and to be installed within a housing to connect electrical modules, e.g. a turn signal module, with a power supply and a control unit outside the automotive side mirror during assembly thereof, with said assembly being described with respect to  FIGS. 2A and 2B  below. 
         [0057]    The FPC  40  of  FIG. 1A  has 7 arms or branches, 6 of said branches being provided with terminals  41  to  46  to be connected to electrical modules, with  FIG. 1B  showing one of said 6 branches connected to one module  50 , whereas the 7th branch is connected to cables  47  for connecting the electrical module  50  to a not shown power supply and a not shown control unit. 
         [0058]    In a pre-assembly step the FPC  40  is connected with 6 modules  50  and the cables  47  by crimping, soldering or the like, to provide one unit. Said unit of the FPC  40 , the 6 electrical modules  50  and the cables  47  looks like a spider (not shown) and, therefore, is called spider in the following. 
         [0059]    In order to connect said pre-assembled spider to the remaining parts of the automotive side mirror in an automated production line with a spider gripper described with respect to  FIGS. 6A and 6B  below, each of said modules  50  is provided with standard gripping points. The electrical module  50  of  FIG. 1B  is formed with opposing recesses  52  providing said gripping points. 
         [0060]    The gripping points providing recesses  52  of each of the 6 modules  50  allow for said spider gripper having 6 arms and, thus, 6 pairs of fingers to grip each of the modules  50  between 2 fingers of one arm for assembly. Each free end of an arm of the spider gripper has a small pneumatic or hydraulic cylinder or electrically operated motor based system for gripping one electric module  50  between 2 fingers engaging the module  50  within its recess  52  at two opposite sides, introducing the module  50  into a corresponding mirror part and ejecting the module  50  between said 2 fingers at the end of the assembly. 
         [0061]    The modules  50  can be provided as MIDs with a plastic molding housing electrical components comprising e.g. a lightning unit to form in particular a turn signal module and providing conducting paths obtained by Laser Direct Structuring (LDS). The plastic molding can be provided with further structural features facilitating the assembly of the modules  50  of the spider to the remaining automotive mirror parts. 
         [0062]    In case the module is to function as a turn signal module  500  connected to a flexible printed circuit board  400 , it is to be assembled with a light guide unit  20  during the assembly thereof to a housing part  10  as will be explained with respect to  FIGS. 2A and 2B  in the following. 
         [0063]    The light guide unit  20  is provided with a plurality of clip connection elements  21 ,  22  formed together with a housing  23  which is also provided with an opening  24  for inserting the turn signal module  500  between the housing  23  and a light guide  25 . 
         [0064]    The clip connection elements  21  are suited for engaging mating clip connection elements  11  provided by the housing part  10 . The housing part  10  is formed in addition with further clip connection elements  12  for the connection of a mirror foot  30  extending through an opening  14  provided within the housing  10 . The direction of assembly of the mirror parts  10 ,  20  and  30  is indicated by the arrow A in  FIG. 2A . 
         [0065]    The light guide unit  20  does not include any electronic element, in particular no lighting unit. All electronic elements required for providing a turn signal are arranged within the turn signal module  500  to be introduced into the opening  24  during assembly. 
         [0066]    In an aspect, the two pre-assembled parts, namely a spider comprising the flexible printed circuit board  400 , the turn signal module  500  and a cable harness  470 , and a unit with the light guide  20 , the housing part  10  and the mirror foot  30 , are connected to each other via snap connections, with the assembly direction being indicated by the arrows B in  FIG. 2B . 
         [0067]    The turn signal module  500  is provided with opposing gripping edges  520  at its upper end facing away from the light guide unit  20  in  FIG. 2B . Said gripping edges  520  can be gripped by said spider gripper, which can move the module  500  in assembly direction B to enter the opening  24 . 
         [0068]    The turn signal module  500  is provided with a opposing guiding faces  510 ,  511  providing a tapering facilitating the insertion of the turn signal module  500  into the opening  24 . The turn signal module  500  is slided into the opening  24  by the spider gripper until an abutment of the guiding faces  510 ,  511  against corresponding surfaces of the housing  23 , with a final locking by a snap connection. For that purpose the module  500  is provided with a snap connection element  513  in form of a hole into which a hook (not shown) provided within the light guide units  20  can enter. 
         [0069]    In the assembled position of the turn signal module  500  within the light guide unit  20  a connection  532  of conducting paths  530  of the module  500  to the flexible printed circuit board  400  is arranged within the region of the opening  24 . Still further, a sealing member  540  provided in form of a projection of the module  500  seals the connection between the light guide unit  20  and the exterior of the automotive mirror  1  to be assembled. 
         [0070]    The spider gripper is detached from the module  500  as soon as the same has been placed into its final position within the opening  24 . 
         [0071]    Further mirror parts of an automotive side mirror will be described in the following, namely in form of a housing ring as shown in  FIG. 3A , a top cap as shown in  FIG. 4A  and a mirror foot as shown in  FIG. 5A . In order to assemble said mirror parts in an automated production line with a standard or rather common gripper each part is provided with standard gripping points. 
         [0072]    The housing ring  111  shown in  FIG. 3A  includes a plurality of straps  112  each providing standard gripping points. This is further illustrated by  FIG. 3B  showing a standard gripping unit  100  with two gripping fingers  102  each having an inner surface  104  with a recess  106  and an outer surface  108  with a recess  110 . Each strap  112  can be gripped between the inner surfaces  104  of the gripping fingers  102  of the gripping unit  100  in a standard manner. 
         [0073]    The top cap  120  of  FIG. 4Aa  includes two different kinds of standard gripping points in form of clips  122  and  124 . The clips  122  correspond substantially to the straps  112  shown in  FIG. 3A  and can be gripped between the inner surfaces  104  of the gripping fingers  102  of the gripping unit  100 , whereas the clip  124  is gripped by the outer surfaces  108  of the gripping fingers  102  of the gripping unit  100  by entering the gripping fingers  102  into recesses  126   a ,  126   b  as best seen in  FIGS. 4B and 4C . 
         [0074]    The clips  122  can also serve to enable a snap connection with another housing part of the automotive side mirror. 
         [0075]    The mirror foot  130  of  FIG. 5A  is provided with two cut outs  132  forming standard gripping points with can be gripped between the inner surfaces  104  of the gripping fingers  102  of the gripping device  100  as shown in  FIG. 5B . 
         [0076]    In order to handle a plurality of mirror parts, in particular in form of the spider provided by the flexible circuit board  40  having modules  50  attached to its plurality of branches as discussed with respect to  FIGS. 1A and 1B ; a gripping device  1000  may also be used as shown in  FIG. 6A . Such a gripping device  1000  is provided with a center spine  1002  which is connected at its upper end in  FIG. 6A  to a tool connection means  1004  for the attachment to a not shown robot and at its lower end to six gripping units  1100 . Via a center spine placing means  1006  operated by supplying air to air nipples  1008  the center spine  1002  can be moved upwards and downwards whereas a rotation of the center spine  1002  can be achieved manually. 
         [0077]    Each gripping unit  1100  includes an arm having two parts, in form of an upper gripping arm  1102  and a lower gripping arm  1104 , which can be pivoted with respect to each other via an arm bending means  1200  provided with an air nipple  1202  pneumatically moving a piston  1204 . At the free end of the arm of each gripping unit  1100  a pair of gripping fingers  1106  is provided, as best seen in  FIG. 6B . The fingers  1106  of each pair cooperate with ejecting means  1300  each provided with an air nipple  1302  in order to pneumatically move a piston  1304  to eject an article gripped between the two gripping fingers  1106 . 
         [0078]    The gripping device  1000  can be controlled to move its gripping units  1100  like the legs of a spider with the additional advantage of fingers of a human palm. With this particular design it is possible to grip each of the 6 branches of the flexible circuit board  40  shown in  FIG. 1A  between a pair of gripping fingers  1106  and move said branches in different directions relative to each other allowing a high degree of freedom with respect to the arrangement of the electrical modules  50  within the automotive side mirror  1  and still have them all connected to the power supply via the electrical circuit board  40 . 
         [0079]    Thus, the gripping device  1000  is not restricted to handling articles to be assembled in a single production direction, but provides a high degree of freedom enabling an optimal usage of flexible circuit boards. This also speeds up the manufacturing of automotive mirrors. 
         [0080]    Although modifications and changes may be suggested by those skilled in the art, it is the intention of the application to embody within the patent warranted hereon all changes and modifications as reasonably and probably come within the scope of this contribution to the art. The features of the present invention which are believed to be novel are set forth in detail in the appended claims. The features disclosed in the description, the figures as well as the claims could be essential alone or in every combination for the realization of the invention in its different embodiments. 
       REFERENCE SIGN LISTING 
       [0000]    
       
           1  automotive mirror 
           10  housing part 
           11 ,  12  clip connection element 
           14  opening 
           20  light guide unit 
           21 ,  22  clip connection element 
           23  housing 
           24  opening 
           25  light guide 
           30  mirror foot 
           40  flexible printed circuit board 
           41 - 46  terminals 
           47  cables 
           50  electrical module 
           52  recess 
           60  mirror plate adjustment unit 
           100  gripping unit 
           102  gripping finger 
           104  inner surface 
           106  recess 
           108  outer surface 
           110  recess 
           111  housing ring 
           112  strap 
           120  top cap 
           122  clip 
           124  clip 
           126   a ,  26   b  recess 
           130  mirror foot 
           132  cut out 
           400  flexible printed circuit board 
           470  cable harness 
           500  turn signal module 
           510 ,  511  guiding face 
           513  snap connection element 
           520  gripping edge 
           530  conducting paths 
           532  connection to flexible printed circuit board 
           540  sealing member 
           1000  gripping device 
           1002  center spine 
           1004  tool connection means 
           1006  center spine placing means 
           1008  air nipple 
           1100  gripping unit 
           1102  upper gripping arm 
           1104  lower gripping arm 
           1106  gripping finger 
           1200  arm bending means 
           1202  air nipple 
           1204  piston 
           1300  ejecting means 
           1302  air nipple 
           1304  piston 
         A, B assembly direction