Abstract:
Windshield wiper device ( 400 ) for a motor vehicle with at least one wiper bearing ( 42 ) and a fastening element ( 44 ) that is connected to a vehicle body, wherein a decoupling element ( 43 ) for decoupling noise is arranged between the at least one wiper bearing ( 42 ) and the fastening element ( 44 ), wherein the decoupling element ( 43 ) and/or the wiper bearing ( 42 ) is detachably connected to the fastening element ( 44 ).

Description:
BACKGROUND OF THE INVENTION 
     The invention relates to a windshield wiper device for a motor vehicle with at least one wiper bearing and a fastening element that is connected to the vehicle body, wherein a decoupling element for decoupling noise is arranged between the at least one wiper bearing and the fastening element. 
     Pedestrians are completely unprotected in collisions with motor vehicles. In particular, the unyielding, hard parts beneath the engine hood often produce severe injuries when a pedestrian impacts a vehicle. The windshield wiper device is located in an area where pedestrians frequently hit a vehicle in an impact. The windshield wiper devices generally known from the prior art have the disadvantage that they represent a great danger of injury for a pedestrian in an impact with a vehicle. 
     SUMMARY OF THE INVENTION 
     The objective of the invention is improving a windshield wiper device of the type mentioned at the outset to the effect that in the future the danger of injury for a pedestrian in an impact with a vehicle is reduced. 
     The invention attains the stated objective via a windshield wiper device for a motor vehicle with at least one wiper bearing and a fastening element that is fastened to the vehicle body, wherein a decoupling element for decoupling noise is arranged between the at least one wiper bearing and the fastening element, wherein the decoupling element and/or the wiper bearing is detachably connected in accordance with the invention to the fastening element. Because of the detachable connection of the decoupling element and/or the wiper bearing to the fastening element, the decoupling element and/or the wiper bearing can detach from the fastening element by the impact of a pedestrian so that the decoupling element and/or the wiper bearing give way during an impact, and thereby reduce the pedestrian&#39;s risk of injury in an impact with the windshield wiper device. 
     In one development of the invention, the fastening element and/or the decoupling element are provided with an undercut, wherein the fastening element and/or the decoupling element are manufactured of a deformable material. The undercut on the fastening element and/or on the decoupling element affects a lock of the decoupling element on the fastening element in an axial direction of a wiper bearing shaft. This lock is necessary to guarantee its proper functioning when the windshield wiper device is in operation. Because the fastening element and/or the decoupling element are manufactured of a deformable material, in the case of a pedestrian impact with the vehicle, the lock between the fastening element and the decoupling element can be detached despite the undercut. As a result, the decoupling element and/or the wiper bearing yields to the impact. Consequently, the pedestrian&#39;s risk of injury is reduced considerably. 
     The undercut can be realized structurally very simply by a material projection in the end area of the fastening element. This material projection can be embodied advantageously as a thickening. The required impact force that must prevail in order to detach the decoupling element from the fastening element is defined as a function of the size of thickening. 
     In order to be able to dissipate the impact energy uniformly and not jerkily, the material projection in the end area of the fastening element can feature several teeth arranged one after the other. If the pedestrian impacts the windshield wiper device in accordance with the invention, the decoupling element is displaced over the successively arranged teeth by the impact, which teeth during displacement of the decoupling element generate a relatively high frictional force opposing the impact force. As a result, the impact energy is converted to thermal energy and thereby dissipated. 
     In another embodiment of the invention, the undercut can have a hook-shaped end area of the decoupling element. In an impact, the wiper bearing can press against the decoupling element on this hook-shaped end area so that in an impact the wiper bearing together with the decoupling element is displaced along the wiper bearing shaft and thereby detached from the fastening element. 
     In order to be able to better define the force required to detach the lock between the decoupling element and the fastening element, a disk can be arranged between the material projection in the end area of the fastening element and the hook-shaped end area of the decoupling element. For this reason, it is also possible that the undercut on the fastening element feature a diagonal bearing surface on which the disk or the decoupling element rests. The force to detach the decoupling element from the fastening element can be defined as a function of the angle of this diagonal bearing surface. 
     Expediently, there is a displacement path between a wiper arm and the fastening element in case of an impact with the windshield wiper device. 
     For reasons of optimal deformability during impact, the decoupling element can be manufactured of a plastic, in particular an elastomer. For the same reason, it is also possible to manufacture the fastening element of a plastic. Also for reasons related to easy manufacturability of the relatively complicated form of the decoupling element and the fastening element, it is meaningful if the decoupling element and the fastening element are manufactured of a plastic. 
     In order to achieve cost savings with high unit numbers, and in order to optimize process control in the case of a highly automated manufacturing concept, it is advantageous if the at least one wiper bearing and/or fastening element and/or the decoupling element are standardized non-variable parts. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Various exemplary embodiments of a windshield wiper device in accordance with the invention are explained in greater detail on the basis of the enclosed drawings. 
       In detail the drawings show: 
         FIG. 1  A perspective top view of a windshield wiper device in accordance with the invention; 
         FIG. 2  An exploded view of the windshield wiper device from  FIG. 1 ; 
         FIG. 3   a  A side view of the windshield wiper device from  FIG. 1  before an impact with a pedestrian; 
         FIG. 3   b  A side view of the windshield wiper device from  FIG. 1  after an impact with a pedestrian; 
         FIG. 4  A sectional view through the windshield wiper device from  FIG. 3   a  along Line B-B; 
         FIG. 5  A sectional view through a second embodiment of the windshield wiper device in accordance with the invention; 
         FIG. 6  A detailed view of a detail in the end area of a wiper bearing from  FIG. 5 ; 
         FIG. 7  A sectional view through a third embodiment of the windshield wiper device in accordance with the invention; 
         FIG. 8  A detailed view of a detail in the end area of a wiper bearing from  FIG. 7 . 
     
    
    
     DETAILED DESCRIPTION 
       FIGS. 1 ,  2 ,  3   a  and  3   b  show a windshield wiper device  100  with a wiper arm  10 , which is connected to a wiper bearing  12  by means of a wiper bearing shaft  11 . A crimp peg  13  to accommodate a mounting plate tube (not shown here) is arranged on the wiper bearing  12 . A fastening element  14  is attached above the wiper bearing  12  and this fastening element can be used to fasten the windshield wiper device  100  in accordance with the invention to a vehicle body (also not shown here). A decoupling element  15  to decouple noise is provided between the fastening element  14  that is fastened to the vehicle body and the wiper bearing  12 . The decoupling element  15  is inserted axially into the wiper bearing  12  during assembly. The fastening element  14  is also inserted axially into the decoupling element  15  (see  FIG. 2 ). As depicted in  FIG. 2 , the fastening element  14  has connecting pieces  20 , which can be inserted into the openings  21  in the decoupling element  15  during assembly. The decoupling element  15  has connecting pieces  22 , which can be inserted into openings  23  in the wiper bearing. Since the decoupling element  15  and the wiper bearing  12  are detachably connected to the fastening element  14 , the wiper arm  10  can be pressed downward by a displacement path  15  via impact force F. 
       FIG. 4  shows a windshield wiper device  400  with a wiper shaft  40 , on which a wiper arm  41  is attached. The wiper shaft  40  is positioned in a wiper bearing  42 . A decoupling element  43  is mounted on the wiper bearing  42  and a fastening element  44  is arranged on the decoupling element  43 . The fastening element  44  features a thickening  45 , around which a correspondingly formed undercut  46  on the decoupling element  43  grips. As a result, the undercut  46  and the thickening  45  form a lock of the decoupling element  43  with the fastening element  44 . This lock is a function of how strongly the thickening  45  and the undercut  46  are embodied. Furthermore, the decoupling element  43  features a hook-shaped end area  47 . The wiper bearing  42  is supported on this hook-shaped end area  47  during an impact. As a result, the wiper bearing  42  can displace the decoupling element  43  downward during an impact. During the downward displacement of the decoupling element  43 , the decoupling element  43  with its undercut  46  is pushed over the thickening  45 . As a result, the thickening  45  and the undercut  46  determine a detachment force required in order to detach the lock formed by the thickening  45  and the undercut  46 . Since the decoupling element is frequently manufactured of an elastomer, the force required to detach the lock between the thickening  45  and the undercut  46  is a function of not just their dimensions but also of the hardness of the elastomer. 
       FIGS. 5 and 6  show a windshield wiper device  500  with a wiper bearing  50 , a fastening element  51  and a decoupling element  52 . The decoupling element  52  includes a hook-shaped end area  55 . A disk  53  is arranged between the fastening element  51  and the decoupling element  52 . The disk  53  is locked in the upward axial direction by a thickening  54 . In the case of an impact, the wiper bearing  50  together with the decoupling element  52  is pressed downward, whereby the disk  53  is pushed over the thickening  54 , thereby detaching the lock. 
       FIGS. 7 and 8  show a windshield wiper device  700  with a wiper bearing  70 , a fastening element  71  and a decoupling element  72 . A disk  73  is arranged between the decoupling element  72  and the fastening element  71 . Teeth  74  arranged one after another extend beneath the disk  73 . In the case of an impact with a pedestrian, the wiper bearing  70  together with the decoupling element  72  and the disk  73  are displaced downward. During this displacement, the disk  73  is pushed over the successively arranged teeth  74  so that the impact force counteracts an increased frictional force. As a result, the impact energy is converted to thermal energy and therefore uniformly dissipated. The frictional force counteracting the impact force can be specified in accordance with the inclination of the flanks of the teeth  74 .