Abstract:
Fluid distribution valve ( 11 ), particularly for a vehicle screen wash system, characterized in that it comprises a body ( 41 ) defining a duct ( 43 ) for the passage of fluid and comprising at least one fluid inlet ( 45 ) and at least one fluid outlet ( 47, 49 ), a membrane ( 53 ) housed in the duct and configured to be deformed under the action of a magnetic field between a first position of at least partial closure of the duct and a second position of at least partial opening of the duct, and means ( 51 ) for generating a magnetic field within the duct in order to cause the membrane to deform.

Description:
TECHNICAL FIELD 
       [0001]    The present invention concerns a fluid distribution valve in particular for a vehicle windshield washer liquid distribution system. 
       PRIOR ART 
       [0002]    There are known motor vehicle windshield wiper systems comprising windshield wipers carrying windshield washing devices, each of the wipers including one or two windshield washer liquid sprayer manifolds. In the case of a wiper including a single manifold (mono-manifold), the manifold extends on one side of the wiper to spray windshield washer liquid onto the windshield. The liquid is generally sprayed ahead of the moving wiper so as to be wiped immediately and not interfere with the driver&#39;s view. For example, the liquid is sprayed in the upward direction and spraying is stopped for the movement of the arm in the downward direction. In some applications the water can be sprayed behind the wiper, to allow the liquid time to interact with the pollutants that have to be eliminated. 
         [0003]    The supply of windshield washer liquid to the manifold necessitates a pipe feeding the liquid to the manifold from a single-channel pump taking the windshield washer liquid from a windshield washer liquid tank disposed under the hood of the vehicle. 
         [0004]    In the case of a wiper including two manifolds (bi-manifold), there is a manifold on each side of the wiper. These manifolds are designed to spray the windshield washer liquid onto the windshield alternately in the upward direction and the downward direction of rotation of the wiper. The supply of windshield washer liquid to these manifolds necessitates two separate pipes feeding the liquid to the manifolds from a two-channel pump taking up liquid from the tank. However, installing these two pipes as far as the sprayer manifolds is relatively complicated, in particular at the level of the wiper drive arms along which the available interior space is small. 
         [0005]    Also, the two visible pipes on the arm are often perceived as relatively unaesthetic, there being also a requirement to improve the visual appearance of the liquid supply arrangement. 
         [0006]    The two pipes also have a negative impact on aerodynamic performance. 
         [0007]    To alleviate these drawbacks wiper systems have already been proposed in which the two sprayer manifolds are connected to a single pipe enabling said manifolds to be fed from a single-channel pump. The windshield washer liquid is distributed into one and/or the other of said sprayer manifolds by at least one valve directing the windshield washer liquid into the selected sprayer manifold or manifolds. 
         [0008]    The invention aims in particular to improve this technology by means of a new type of valve that makes it possible for example to distribute the windshield washer liquid from a single-channel pump to one or two (or even more) sprayer manifolds. 
         [0009]    However, this new type of pump is not limited to this particular application and can be used in any application necessitating distribution of fluid. 
       SUMMARY OF THE INVENTION 
       [0010]    To this end the invention proposes a fluid distribution valve, in particular for a vehicle windshield washer liquid distribution system, characterized in that it comprises a body defining a duct for the passage of fluid and including at least one fluid inlet and at least one fluid outlet, a membrane housed in the duct and configured to be deformed by a magnetic field between a first position of at least partial closure of the duct and a second position of at least partial opening of the duct, and means for generating a magnetic field inside the duct in order to control the deformation of the membrane. The valve according to the invention is therefore controlled by means of a magnetic field, the application of that magnetic field inducing a movement of the membrane. This technology advantageous makes it possible to circumvent the mechanical constraints. 
         [0011]    In the present application, at least partial closure (respectively opening) of the duct means the closure (respectively opening) of at least one inlet or outlet of the duct. The membrane can be configured to block at least part of the duct, in particular at least one outlet of the duct, in its first position, corresponding to the absence of an applied magnetic field. In this first position, the membrane can have a profile of non-plane shape. 
         [0012]    On application of the magnetic field, the membrane is deformed and adopts a position in accordance with the field lines termed the second position. In this second position the membrane can be at least in part pressed against an internal wall of the duct. It can have a profile of substantially plane shape in this second position. The membrane is preferably made from a flexible material and is for example made from a polymer material, notably from silicone. 
         [0013]    According to one embodiment of the invention, this membrane contains magnetic particles. When acted on by the magnetic field generated by said means the magnetic particles are able to deform the membrane. The application of the magnetic field can therefore lead to deformation of the membrane and opening or closing of the duct. To be more precise, the particles carried by the membrane will become aligned with the field lines on application of the magnetic field and will lead to the deformation of the membrane and its movement from one position to another. 
         [0014]    The membrane may be fixed to an internal wall of the duct. 
         [0015]    The means for generating the magnetic field preferably comprise a winding of at least one electrical wire around the part of the duct housing the membrane. This winding forms a coil—or solenoid—that is intended to be connected to a power supply. The valve according to the invention can therefore be considered a solenoid valve. It is the flow of current in the winding that induces a magnetic field. 
         [0016]    This winding can be configured to generate heat for heating the fluid. This is advantageous if there is a risk of the fluid freezing. 
         [0017]    The valve can be integrated into a fluid pipe. Alternatively the valve is connected to a pipe of this kind. For example, the fluid inlet includes a connector for connecting it to the feed pipe coming from the pump and/or the fluid outlet includes a connector for connecting it to a sprayer manifold. In the context of the invention, by sprayer manifold is meant any vehicle windshield washer liquid sprayer device known to a person skilled in the art, and the sprayer manifold includes a plurality of sprayer nozzles, for example. In a variant the manifold is a simple nozzle. 
         [0018]    According to another aspect, the present invention consists in a hydraulic connector for a vehicle windshield washer liquid distribution system comprising at least one valve according to the invention. 
         [0019]    According to a further aspect, the present invention consists in a vehicle windshield washer liquid distribution system comprising at least one valve as described above. 
         [0020]    The present invention also concerns a vehicle windshield wiper system comprising at least one valve as described above. 
         [0021]    That system may comprise a pump, for example a single-channel pump, at least one wiper and at least one sprayer manifold connected to the pump by said valve. The latter is situated on the wiper, for example. 
         [0022]    In the case of a mono-manifold wiper the valve has an inlet connected to the pump and an outlet connected to the manifold and is termed a two-port valve. In the case of a bi-manifold wiper the valve is of the three-port type and has an inlet connected to the pump and two outlets connected to respective manifolds. 
         [0023]    The valve may be integrated into means for connecting the wiper to a drive arm of said wiper. Alternatively, the valve is integrated into an end fitting of the wiper. 
         [0024]    In one embodiment the wiper system also comprises a wiper drive arm on which the sprayer manifold is situated, for example. 
         [0025]    In another variant it can be mounted under the hood of the vehicle equipped with the wiper system. 
         [0026]    In a further variant, the valve is used to feed nozzles or manifolds integrated into a wiper arm and functions on the same principle to control spraying. 
         [0027]    The present invention also concerns a system for cleaning a motor vehicle driver assistance device, in particular imaging means or electromagnetic detection means, said system comprising at least one fluid distribution valve according to any of the above definitions. By “imaging means” is meant for example a video camera and by “electromagnetic detection means” is meant for example radar or lidar means. Sensors are fitted to an increasingly large number of motor vehicles in order to assist the driver of the vehicle in certain driving situations, one well known instance of which is assisting parking. For this assistance to be as effective as possible, the images supplied by the imaging means or the data transmitted by the radar, for example, must be of the best possible quality and it is therefore essential for the faces of these sensors facing toward the exterior of the vehicle to be clean. To this end, a device for cleaning the sensor may be associated with the sensor and controlled so as to inject a flow of cleaning fluid onto said sensor before detection occurs. It is beneficial to control the device to determine the start and the duration of the cleaning sequence and if necessary to be able to retract the cleaning device after use, in order for it not to impede detection when the sensors are operating, and in order to protect them from impacts, for example. Moreover, it must be as compact as possible to satisfy constraints on the overall size of the vehicle. It is moreover a requirement that such devices enable the injection of different fluids, whether gases or liquids. In fact, if a cleaning liquid is sprayed onto the sensor, for example the lens of an imaging video camera, to expel dirt from it, it is beneficial to dry that lens quickly in order to prevent any risk of pollution of the images by any traces that such a liquid may leave behind (droplets, streaks, etc.). Equipping a driving assistance device of this kind with a cleaning system of this kind comprising a valve according to the invention is therefore particularly advantageous, the latter valve being compact and if necessary controllable directly by a magnetic field generated by an electric current for supplying power to said driver assistance device. This avoids the requirement for additional means to control the valve according to the invention. 
         [0028]    The present invention further concerns a vehicle, in particular a motor vehicle, characterized in that it comprises at least one valve or one system as described above. 
         [0029]    The present invention further concerns a method of controlling a fluid distribution valve, in particular for a vehicle windshield wiper system, characterized in that it comprises a step of generating a magnetic field inside a duct of the valve in order to move a membrane housed in said duct from a first position of at least partial closure of the duct to a second position of at least partial opening of the duct. 
     
    
     
       DESCRIPTION OF THE FIGURES 
         [0030]    The invention will be better understood and other details, features and advantages of the invention will become apparent on reading the following description given by way of nonlimiting example and with reference to the appended drawings, in which: 
           [0031]      FIG. 1  is a diagram showing a vehicle windshield wiper system, 
           [0032]      FIG. 2  is a perspective view of a wiper of a vehicle windshield wiper system, 
           [0033]      FIGS. 3 and 4  are diagrams showing in axial section two different positions of a valve according to the invention for a bi-manifold wiper, and 
           [0034]      FIGS. 5 and 6  are diagrams in axial section similar to  FIGS. 3 and 4  and showing a variant embodiment of the valve according to the invention for a mono-manifold wiper. 
       
    
    
     DETAILED DESCRIPTION 
       [0035]    In the remainder of the description the terms longitudinal and lateral refer to the orientation of the drive arm on which the wiper is mounted. The longitudinal direction corresponds to the main axis of the arm along which it extends and the lateral orientations correspond to straight line segments that are concurrent, i.e. that cross the longitudinal direction, notably perpendicularly to the longitudinal axis of the arm in its plane of rotation. For the longitudinal directions, the terms front and rear are to be understood relative to the point at which the wiper is fixed to the arm, the term front designating the direction from the distal end of the arm and the term rear the opposite direction. Moreover, the directions referred to as upper or lower correspond to orientations perpendicular to the plane of rotation of the arm, the term lower containing the plane of the windshield. 
         [0036]    Finally, identical reference numbers are used to designate identical or analogous elements. 
         [0037]    Refer first to  FIG. 1 , which shows a system  1  for wiping the windshield  3  of a motor vehicle, that system here including a bi-manifold wiper  5  for wiping the windshield  3  that is shown detached from a drive arm  7 . The wiper  5  includes two windshield washer liquid sprayer manifolds  9  mounted on the wiper. 
         [0038]    The wiper system  1  further comprises windshield washer liquid supply means that comprise a valve  11  according to the invention for selective distribution of windshield washer liquid to each of the manifolds  9 , a windshield washer liquid feed pump  15  and a feed pipe for feeding the windshield washer liquid from the pump  15  to the valve  11 . The valve  11  is connected to the manifolds  9  by two pipes  17 . 
         [0039]    In the example shown, the wiper system  1  includes a single wiper  5  disposed substantially at the center of the windshield  3 . The wiper system  1  could alternatively include two wipers, one disposed facing the driver and one disposed facing the passenger. 
         [0040]    The manifolds  9  extend substantially over the length of the wiper, on each side and on its longitudinal axis. These manifolds  9  are therefore adapted to spray the windshield washer liquid along the wiper. 
         [0041]    The wiper  5  is mounted on the drive arm  7  so that it can be driven by the latter to wipe the windshield  3  with a cyclic rotation movement over the windshield substantially in part of a circle about a rotation axis  19 . 
         [0042]    The pump  15  for feeding the manifolds  9  with windshield washer liquid is itself connected to the valve  11  by means of the feed pipe  13 , which here is a flexible pipe, and to a windshield washer liquid container  21  from which the liquid is taken to be fed to the manifolds  9 . 
         [0043]    The feed pipe  13  and an electrical power supply cable  25  of the valve  11 , preferably connected to the pipe  13 , are for example housed at least in part in the arm  7  and in part under the hood  23  of the vehicle. 
         [0044]    The valve  11  according to the invention can be mounted at the distal end  31  of the arm  7 , for example at the level of an arm headpiece. 
         [0045]    The valve  11  is preferably at least in part integrated into a hydraulic connector  33  configured to establish a hydraulic connection of the valve  11  to the manifolds  9 , as seen in  FIG. 2 , so that at least its two outlets are configured to form part of the hydraulic connector intended to be connected to the wiper. 
         [0046]    The hydraulic connector  33  is disposed on the arm  7 , not shown in  FIG. 2 . Here the wiper  5  further includes a mechanical connector  35  and an adapter  36  articulated to the mechanical connector and configured to be locked onto the arm  7 . 
         [0047]    The valve  11  and the pump  15  are connected to a control unit  37  which is for example the body controller of the vehicle, forming means for combined control of the valve and the pump. 
         [0048]    This control unit  37  can manage the operation of the valve  11  and the pump  15  in accordance with a plurality of distinct operating modes. One of those modes can provide in a cleaning cycle continuous activation of the pump  15  and selective control of the valve  11  as a function of the various positions of the wiper  5  on the windshield  3  in an associated wiping cycle. 
         [0049]    Refer next to  FIGS. 3 and 4 , which are diagrams showing a first embodiment of the valve  11  according to the invention. 
         [0050]    The valve  11  comprises a body  41  defining a duct  43  for the windshield washer liquid and here including an inlet  45  and two outlets  47 ,  49 . The first outlet  47  is for example aligned with the inlet and the second outlet  49  is lateral and here is substantially perpendicular to the inlet  45 , the duct  43  therefore being substantially T-shaped. As explained above, the inlet  45  of the valve is connected by the pipe  13  to the pump  15  and the outlets  47 ,  49  of the valve are connected to the respective pipes  17 . 
         [0051]    The body  41  comprises a main part  41   a  defining the inlet  45  and the first outlet  47  and a branch  41   b  that defines the second outlet  49 . The main part  41   a  of the body is surrounded by a winding  51  consisting of electrical wire(s) that forms a coil or solenoid and is connected to a power supply, not shown, via the power supply cable  25  of the control unit  37 . This winding  51  can take the form of one or more layers of electrical wire on the part  41   a  of the body. Alternatively, the winding  51  can be integrated into the body  41  of the valve so as to extend around the duct  43  over a part of its length. The valve  11  further comprises a membrane  53  mobile between a first position of at least partial closure of the duct  43  ( FIG. 3 ) and a second position of at least partial opening of the duct ( FIG. 4 ). 
         [0052]    The T-shape of the duct of a three-channel valve is not limiting on the invention. The inlet and the two outlets can therefore form a Y or any other shape appropriate to the shape of the mobile membrane and to the integration of the valve into the system. 
         [0053]    In the example shown, when the membrane  53  in its first position ( FIG. 3 ) it blocks the first outlet  47  of the duct and leaves its second outlet  49  free. When the pump  15  is activated the windshield washer liquid flows from the inlet  45  to the second outlet  49  of the valve to feed windshield washer liquid to one of the manifolds  9  of the wiper  5  (arrow  55 ). 
         [0054]    When the membrane  53  is in its second position it blocks the second outlet  49  of the duct and leaves its first outlet  47  free. When the pump  15  is activated the windshield washer liquid flows from the inlet  45  toward the first outlet  47  of the valve to supply windshield washer liquid to the other manifold  9  of the wiper  5  as shown by the arrow  57 . 
         [0055]    The membrane  53  is deformed between the first and second positions by application of a magnetic field in the duct  43  and in particular in the part of the duct housing the membrane. 
         [0056]    Here the membrane  53  is housed in the main part  41   a  of the duct. Here, in the absence of an applied magnetic field, the membrane  53  is in the first position shown in  FIG. 3 . Immediately on application of a magnetic field induced by the supply of electrical power to the winding  51  the membrane  53  is deformed and adopts the second position shown in  FIG. 4 . 
         [0057]    To this end the membrane  53  is made from a supple or flexible material (such as a polymer material) and contains magnetic particles that are intended, when acted on by the magnetic field, to deform the membrane and to move it from its first position to its second position. Upon application of the magnetic field the particles carried by the membrane are aligned parallel to the field lines  59 , which deforms the membrane  53 . 
         [0058]    In the example shown, the membrane  53  is fixed substantially at its center to the internal wall of the main part  41   a  of the body. It comprises an upstream part  61  (in relation to the direction of flow of the liquid in the duct  43 ) that can be deformed between a position in which it is applied to the peripheral edge of the mouth  63  of the second outlet  49  in the duct and therefore blocks that outlet  49  ( FIG. 4 ) and a position in which its free end contacts an internal surface of the duct  43  situated facing the mouth  63  and therefore blocks the first outlet  47  ( FIG. 3 ). 
         [0059]    The membrane  53  also comprises a downstream part  65  that can be deformed between a position in which it is applied to an internal surface of the duct  43  situated on the same side as the mouth  63  and therefore leaves the first outlet  47  free ( FIG. 4 ) and a position in which its free end contacts an internal surface of the duct situated on the side opposite the mouth  63  and therefore blocks the first outlet  47  ( FIG. 3 ). 
         [0060]    In its position represented in  FIG. 3  the membrane  53  has the shape of a U or a V with a median part fixed to the internal wall of the duct  43  and the branches of which form the aforementioned upstream part  61  and downstream part  65 , respectively. In the position shown in  FIG. 4  the membrane  53  has a substantially plane shape. 
         [0061]    The general shape of the membrane  53  depends in particular on the shape in section of the duct  43 . When the duct  43  has a square shape in section the membrane  53  can have a rectangular general shape. The membrane  53  can then be designed to be pressed against a plane internal face of the duct  43  in  FIG. 4  and its upstream part  61  and downstream part  65  can each be configured so that its peripheral edges cooperate in fluid-tight manner with the other internal faces of the duct in  FIG. 3 . 
         [0062]    When the duct  43  has a circular shape in section the upstream part  61  and the downstream part  65  of the membrane  53  can each have a circular or oblong general shape. 
         [0063]    The wiper system  1  and the valve  11  from  FIGS. 3 and 4  can operate in the following manner. When the wiper  5  must be fed with windshield washer liquid the control unit  37  activates the pump  15 , which feeds the valve with windshield washer liquid from the container  21 . The winding  51  of the valve  11  can at this stage remain unenergized so that the membrane  53  remains in the first position shown in  FIG. 3 , in which case the windshield washer liquid feeds the manifold of the wiper connected to the second outlet  49 , for example during rotation of the wiper in the upward direction. The control unit  37  then activates the valve  11 , i.e. activates the supply of electrical power to the winding  51 . The membrane  53  is then moved into the second position shown in  FIG. 4  so that the windshield washer liquid flows to the manifold of the wiper connected to the first outlet  47 , for example during rotation of the wiper in the downward direction. 
         [0064]      FIGS. 5 and 6  show a variant embodiment of the valve according to the invention, this valve  11  including an inlet  45  and only one outlet  47  and therefore being of the two-port type, which can be used to feed washer liquid to a mono-manifold wiper. The references used in relation to  FIGS. 3 and 4  are used again to designate the same elements in  FIGS. 5 and 6 . 
         [0065]    The essential structural difference between the embodiments of  FIGS. 3 and 4  on the one hand and  FIGS. 5 and 6  on the other hand is that the body  41  of the valve does not include a branch. In its first position shown in  FIG. 5 , the membrane  53  completely blocks the duct  43  and in its second position shown in  FIG. 6  it leaves the duct  43  free. 
         [0066]    The control unit  37  can command simultaneous activation of the pump  15  and the valve  11  from  FIGS. 5 and 6 , windshield washer liquid then flowing from the container  21  to the single manifold of the wiper via the duct  43  of the valve  11 . The invention is not limited to the examples that have just been described.