Abstract:
A windshield wiper for a motor vehicle includes an elongate wiper blade and a supply conduit for cleaning fluid leading to outlet openings formed on both sides of the wiper blade. A directional control valve is provided to selectively supply cleaning fluid to either the outlet openings on the first side or the outlet openings on the second side of the wiper blade based on the wiping direction of the wiper blade.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims priority to German Patent Application No. 102015012610.5, filed Sep. 29, 2015, which is incorporated herein by reference in its entirety. 
       TECHNICAL FIELD 
       [0002]    The present disclosure pertains to a windshield wiper for a motor vehicle. 
       BACKGROUND 
       [0003]    Conventional windshield wipers usually have a bracket, in which a flexible wiper blade is held. The bracket is mounted on a wiper arm of the motor vehicle in such a way that the wiper arm presses the wiper blade against the surface of a windshield to be cleaned. The wiper blade is moved over the windshield transverse to its longitudinal direction due to pivoting motions of the wiper arm in order to push aside water located on the windshield. A cleaning fluid can be applied onto the windshield in order to additionally dissolve and remove fatty and albuminous films and coatings or to remove dirt from dry windshields. 
         [0004]    Such cleaning fluids are traditionally applied with the aid of spray nozzles that are mounted on the engine hood and continuously spray as long as the driver actuates a corresponding lever. In this way, nearly the entire windshield is wetted with cleaning fluid including the part of the windshield, over which the wiper blade has just passed. The windshield can be quickly and efficiently cleaned since the wiper blade sweeps over a windshield wetted with cleaning fluid during the forward and the backward motion of the windshield wiper. However, the consumption of cleaning fluid is quite high and the visibility is restricted while the windshield is cleaned. 
         [0005]    In certain windshield wiper blades, such as the AquaBlade® made by Valeo, outlet openings for cleaning fluid are directly integrated into the windshield wiper on one side of the wiper blade. The cleaning fluid is only applied onto the windshield when the outlet openings lie in front of the wiper blade referred to the moving direction of the windshield wiper. In this way, the cleaning fluid is captured by the wiper blade immediately after it is applied onto the windshield and therefore cannot impair the visibility. During the motion in the opposite direction, however, such wiper blades sweep over a dry windshield. Intensive cleaning therefore is only possible during every other motion of the windshield wiper such that the cleaning process is considerably prolonged. 
       SUMMARY 
       [0006]    The present disclosure provides a windshield wiper that makes it possible to quickly clean a windshield and only consumes little cleaning fluid for this purpose. According to an embodiment of the present disclosure, a windshield wiper for a motor vehicle is equipped with an elongate wiper blade and a supply conduit for cleaning fluid leading to at least one respective outlet opening on both sides of the wiper blade. In this way, cleaning fluid can be applied onto a windshield along the wiper blade during a forward motion, as well as during a backward motion, and the windshield can be effectively cleaned in both moving directions of the windshield wiper. 
         [0007]    Multiple outlet openings may be distributed along the wiper blade in order to apply the cleaning fluid onto the windshield over the entire length of the wiper blade. The supply conduit should include a distribution line that extends along the wiper blade between the outlet openings and supplies the outlet openings with cleaning fluid. 
         [0008]    In order to prevent cleaning fluid from being continuously discharged through the outlet openings on both sides of the wiper blade during a wiping process and to prevent the visibility from being impaired by cleaning fluid that runs off the side of the wiper blade facing away from the wiping direction, a directional control valve should be provided for either supplying the outlet openings on the first side or the outlet openings on the second side of the wiper blade with cleaning fluid. 
         [0009]    The wiper blade may be tiltable about a longitudinal axis in a mounting. In this case, the directional control valve can be coupled to the tilting motion in order to supply the outlet opening on the first side with cleaning fluid when the wiper blade is tilted toward the second side. Since the wiper blade is alternately tilted during each change between the forward and the backward motion of the windshield wiper, only the outlet opening lying in front of the wiper blade referred to the moving direction is respectively open. 
         [0010]    In an embodiment, the wiper blade may be accommodated in a groove of a wiper bracket. In order to enable the wiper blade to adapt to the direction of the wiping motion and to tightly adapt to the windshield, at least one sidewall of the groove and a flank of the wiper blade lying opposite of this sidewall should be spaced apart from one another. 
         [0011]    It is advantageous if the outlet openings respectively lead into gaps between a flank of the wiper blade and an opposing sidewall of the groove. When the wiper moves over the windshield, the mobility of the wiper blade causes the gap on the front side of the wiper blade relative to the moving direction to open and the gap on the rear side of the wiper blade relative to the moving direction to close. The respective sidewalls of the groove function as a valve seat and the wiper blade functions as a closing body of the directional control valve, which can be moved between the valve seats, such that cleaning fluid can only be discharged into the gap and subsequently onto the windshield through the outlet openings on the front side of the wiper blade relative to the moving direction. In order to convey cleaning fluid to the outlet openings, a downstream section of the supply conduit may extend in the sidewalls of the groove. 
         [0012]    In another embodiment of the present disclosure, the groove may feature an undercut inner region, into which a leg of the wiper blade engages in a form-fitting fashion in order to fix the wiper blade in the groove without other auxiliary means. 
         [0013]    According to an enhancement of the present disclosure, the inner region has a cross section in the shape of a sector of a circle and the leg of the wiper blade is pivotable about an axis extending in its longitudinal direction in the inner region. In this way, the wiper blade can respectively tilt in accordance with the direction of the wiping motion without having to bend. 
         [0014]    According to a first alternative, the wiper blade may feature a leg that is immovably fixed in the groove, a pivotable outer section and a hinge section, particularly an integral hinge, between the leg and the outer section. 
         [0015]    According to a second alternative, the wiper blade may be anchored with the aid of pins extending across the groove in order to realize a translation of the wiper blade from one sidewall of the groove to the opposite sidewall during each change of the wiping direction. In this case, it is advantageous if the outlet openings are arranged centrally between two pins. If the wiper blade jams and gets stuck at the pins, the outlet opening can thereby still be tightly closed due to the flexibility of the wiper blade. 
         [0016]    In order to allow a simple and cost-effective manufacture of the windshield wiper, the supply conduit may be realized in the form of a channel that is recessed into the sidewalls and/or a bottom of the groove. The channel should extend as far as the outlet opening. The channel is closed by the wiper blade inserted into the groove such that a conduit with closed cross section is formed. Sufficient pressure for spraying the cleaning fluid through the outlet openings can be built up. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0017]    The present disclosure will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements. 
           [0018]      FIG. 1  shows a side view of the windshield wiper; 
           [0019]      FIG. 2  shows a cross section through a windshield wiper with a wiper blade, which can be tilted about its longitudinal axis, according to an embodiment of the present disclosure; 
           [0020]      FIG. 3  shows a cross section through a windshield wiper according to another embodiment along the plane III-III in  FIG. 4 , wherein the wiper blade is anchored with the aid of pins extending across the groove; 
           [0021]      FIG. 4  shows a longitudinal section through the windshield wiper along the plane IV-IV in  FIG. 3 ; 
           [0022]      FIG. 5  shows a one-piece wiper blade according to another embodiment of the present disclosure; 
           [0023]      FIG. 6  shows a cross section through a windshield wiper assembled of the wiper blade according to  FIG. 5  and a bracket; 
           [0024]      FIG. 7  shows a longitudinal section through the windshield wiper according to  FIG. 6 ; 
           [0025]      FIG. 8  shows a cross section through a windshield wiper according to another embodiment of the present disclosure; and 
           [0026]      FIG. 9  shows a longitudinal section through the windshield wiper according to  FIG. 8 . 
       
    
    
     DETAILED DESCRIPTION 
       [0027]    The following detailed description is merely exemplary in nature and is not intended to limit the invention or the application and uses of the invention. Furthermore, there is no intention to be bound by any theory presented in the preceding background of the invention or the following detailed description. 
         [0028]      FIG. 1  shows a windshield wiper  1  that includes a wiper bracket  3  mounted on a wiper arm  2  of a motor vehicle. A wiper blade  4  is fixed on the wiper bracket  3 . A supply conduit  5  for cleaning fluid includes a hose fastened on the wiper arm  2  by clamps. The supply conduit  5  extends up to a connection piece of the wiper bracket  3 , as well as a distribution line  13  that leads to outlet openings  6  arranged along the wiper blade  4  in the wiper bracket  3 . 
         [0029]      FIG. 2  shows a cross section through a wiper bracket  3  and a wiper blade  4  according to an embodiment of the present disclosure. A groove  7  is recessed in the wiper bracket  3 . The leg  9  of the wiper blade  4  is inserted in a form-fitting fashion into an undercut inner region  8  of the groove  7 . The inner region  8  has a cross section in the shape of a sector of a circle. In this way, the leg  9  of the wiper blade  4  is pivotable in the inner region  8  about an axis  10  extending in the longitudinal direction of the wiper blade  4  and perpendicular to the plane of section of  FIG. 2 . The wiper blade  4  pivots from one sidewall  11  of the groove  7  to the opposite sidewall  11  and closes the outlet openings  6  located in this sidewall  11  during each change of the wiping direction. In addition, seals  12  may also be arranged on the wiper blade  4  and positioned on the outlet openings  6  during a wiping motion. When the windshield wiper  1  moves toward the right, the outlet openings  6  on the left sidewall  11  are tightly sealed by the wiper blade  4  whereas fluid can be discharged from the outlet openings  6  on the right sidewall  11  and flow onto the windshield in front of the wiper blade. 
         [0030]    Leg  9  may be realized shorter than a wiping lip  22  of the wiper blade  4  that rests against the windshield and extends over the entire length of the bracket  3 . In this way, it is ensured that the leg  9  can on the one hand extend linearly along the pivoting axis  10  and on the other hand be accommodated in the curved bracket. In such instances, the leg  9  may be rigid whereas the wiping lip  22  integrally formed on the leg  9  is flexible in order to adapt to the curvature of the windshield. However, it is also conceivable that the leg  9  extends along the entire bracket  3  in an arc-shaped fashion. For this purpose, the leg is made of an elastically pliable material like the wiping lip  22 . 
         [0031]    In an alternative embodiment as illustrated in  FIG. 3 , the wiper blade  4  is anchored in the wiper bracket  3  with the aid of pins  14  extending across the groove  7 . The wiper blade  4  ideally slides from one sidewall  11  of the groove  7  to the other sidewall during each change of the wiping direction. In this way, the outlet openings  6  on the rear sidewall  11  relative to the wiping direction (the right sidewall in  FIG. 3 ) are always closed by the wiper blade  4  whereas the outlet openings  6  in the front sidewall  11  relative to the wiping direction W are open. For this purpose, the wiper blade  4  may be divided into a rigid leg  9 , which carries out a pendulum motion between the sidewalls  11  of the groove  7  without deforming, and a flexible wiping lip  22  like the wiper blade according to  FIG. 2 . 
         [0032]    The entire wiper blade  4  may alternatively be flexible. If the wiper blade  4  jams and gets stuck at the pins  14  in this case, it can bend between the pins  14  due to the friction of the wiping lip on the windshield to such a degree that it tightly seals the outlet openings on the rear sidewall  11  relative to the wiping direction W, which are centrally arranged between two pins  14  as illustrated in the longitudinal section according to  FIG. 4 . 
         [0033]      FIG. 5  shows a cross section through an extruded rubber profile  15 , in which the wiper blade  4  and two webs  16  hinged to the wiper blade  4  are realized in one piece. Parallel channels  18  are recessed on flanks  17  of the wiper blade  4  at uniform distances from the plane of section. The extruded profile  15  is provided for being clamped into the groove  7  of the wiper bracket  3  such that its webs  16  are folded against the flanks  17  of the wiper blade  4  as illustrated in  FIG. 6 . The webs  16  form the distribution line  13  in that they are folded against the flanks  17 . The channels  18  are closed over the majority of their length by the webs  16  folded against the flanks  17  of the wiper blade  4  and therefore form conduits with a closed cross section as illustrated, in particular, in  FIG. 7  that shows a longitudinal section along the plane VII-VII in  FIG. 6 . These conduits are only open on their ends lying opposite of the distribution line  13  when the wiper blade  4  is relaxed in order to thereby form the outlet openings  6 . When the wiper blade  4  is laterally deflected in an elastic fashion during its wiping motion over the windshield, the channels  18  are on one side of the wiper blade  4  closed over their entire length by the opposing web  16  and cleaning fluid can only be discharged through the channels  18  on the opposite side of the wiper blade  4 , which lies in front of the wiper blade  4  referred to the moving direction of the windshield wiper  1 . 
         [0034]      FIG. 8  and  FIG. 9  show sections through a windshield wiper  1  according to another embodiment of the present disclosure. The one-piece wiper blade  4  of rubber includes a leg  9 , a hinge section  19  and a pivotable outer section  20 . The leg  9  is immovably fixed in the groove  7  of the wiper bracket  3  with a positive fit. In this case, the distribution line  13  is defined by channels recessed in the wiper bracket  3  and plane surfaces of the leg  9  lying opposite of the channels; however, the distribution line  13  could likewise be defined by channels recessed in the leg  9  and opposing plane surfaces of the bracket  3  or by opposing channels of the leg  9  and the bracket  3 . During each change of the wiping direction, the pivotable outer section  17  pivots toward the rear side of the bracket  3  referred to the wiping direction at the hinge section  16  and thereby seals the outlet openings  6  of the distribution line  13  on this side. 
         [0035]    According to a variation, the pivotable outer section  20  additionally features transversely extending passages  21  that respectively rest against the rear side of the bracket  3  relative to the wiping direction and are aligned with the local outlet openings  6 . In this way, cleaning fluid is deflected from this side toward the opposite side and flows onto the windshield on the front side of the wiper blade  4  relative to the wiping direction W. 
         [0036]    While at least one exemplary embodiment has been presented in the foregoing detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the invention in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing an exemplary embodiment, it being understood that various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope of the invention as set forth in the appended claims and their legal equivalents.