Abstract:
A liquid container is provided that has an opening at the bottom for supplying or removing a liquid, and a groove is formed in the container bottom in the container interior in the area of the opening.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a U.S. National-Stage entry under 35 U.S.C. § 371 based on International Application No. PCT/EP2007/057516, filed Jul. 20, 2007, which was published under PCT Article 21(2) and claims priority to German Application No. 10 2006 035 027.8, filed Jul. 28, 2006, which are all hereby incorporated in their entirety by reference. 
     
    
     TECHNICAL FIELD 
       [0002]    The invention relates to a liquid container, for example, a fuel container or a swirl pot for a fuel container. 
       BACKGROUND 
       [0003]    Fuel containers frequently have an inlet/outlet opening at the bottom for supplying or removing a liquid. An example is the swirl pot of a fuel container via which fuel is intended to flow in from a Venturi nozzle. In order that fuel conveyed into the swirl pot does not flow out again, a mushroom valve is usually located in the opening. Such valves have an elongate stem with a valve shield connected thereto. When viewed in the direction of the stem, the valve shield consisting of an elastic material is generally disposed concentrically with respect to the stem. 
         [0004]    The still-unpublished DE 102006026135.6, which is attributable to the same inventor as the invention described here and incorporated in its entirety by reference, discloses a mushroom valve, which comprises a valve shield with a stem connected thereto, and in which at least one sealing lip is formed on the underside of the valve shield between its sealing edge and the stem. The mushroom valve should allow an improved seal in liquid containers which hold a liquid having solid components as impurities, for example, sand grains or the like. 
         [0005]    It is at least one object of one embodiment of the invention to provide a liquid container and a combination of liquid container and mushroom valve, which have an improved seal in the event that solid components are present in the container liquid. In addition, other objects, desirable features, and characteristics will become apparent from the subsequent summary or detailed description, and the appended claims, taken in conjunction with the accompanying drawings and this background. 
       SUMMARY 
       [0006]    A first embodiment of the invention relates to a liquid container. A first embodiment of the container comprises an opening at the bottom for supplying or removing a liquid, and a groove is formed in the container bottom in the container interior in the area of the opening. 
         [0007]    A liquid container configured in such a manner exhibits an improved seal if a mushroom valve from the still-unpublished document DE 102006026135.6 mentioned in the introductory part of this description of the invention is disposed in the opening located in the bottom thereof. 
         [0008]    The mushroom valve from the still-unpublished document DE 102006026135.6 has at least one sealing lip on the underside of the valve shield so that in use, both the edge of the valve shield and also the said additional sealing lip prevent any escape of liquid from the liquid container. If solid particles such as, for example, sand grains or the like, are located in the liquid container and these penetrate under the edge of the valve shield, this is raised, which results in leakiness of the mushroom valve. The additional sealing lip ensures the seal of the liquid container in this case. 
         [0009]    The groove or elongate indentation in the bottom of the liquid container forms a dwell space for the aforesaid particles and is provided between the sealing edge of the mushroom valve and a sealing lip and/or between two sealing lips of the mushroom valve. If particles penetrate between the sealing edge and a sealing lip or even between two sealing lips due to a raised sealing edge, the particles sink in the groove and penetrate under the following or still-sealing sealing lip with a considerably lower probability compared to a smooth container bottom configuration. In this respect, the groove increases the reliability with which the at least one sealing lip of the mushroom valve can seal the liquid container. 
         [0010]    In one embodiment, the groove forms a closed curve around the opening so that the seal of the liquid container is increased isotropically in its bottom plane. 
         [0011]    In a further embodiment, between one and four grooves are provided, which are spaced apart from one another on a line running through the mid point of the opening. In this way, if the mushroom valve has several sealing lips, for example, between one and four sealing lips, the reliability of each sealing lip is increased. 
         [0012]    Furthermore, embodiments can be provided wherein the at least one groove forms a concentric circle. This form is suitable for a mushroom valve having a cylindrical valve shield with a circular sealing lip in order to achieve an isotropic improvement in the seal in the container bottom plane. 
         [0013]    A further variant of the liquid container provides that the mushroom valve comprises a valve shield with stem connected thereto and at least one sealing lip is formed on the underside of the valve shield between its sealing edge and the stem. 
         [0014]    The liquid container can be configured as a swirl pot for a fuel container of an automobile. In this case, the mushroom valve consists of a material which is initially sufficiently inert with respect to fuels such as gasoline or diesel. Furthermore, it must be sufficiently soft to ensure the seal and should be able to be produced by inexpensive injection molding. In this respect, silicone can be selected as the material. 
         [0015]    The embodiment of the last paragraph has the result that in automobiles, the tank display is given more reliably when the amounts in the fuel tank are small and the residual amount of fuel can be used more reliably. If only a little fuel (e.g., 5 liters or less) is present in the swirl pot, and this residual amount of fuel is measured, the seal of the inlet/outlet opening with its mushroom valve specified in the introductory part of the description influences the accuracy of the measured value. This measured value, which is displayed to the driver by the onboard electronics usually in liters or in kilometers (remaining—which can still be driven) in order to indicate that the tank needs filling up soon, can exhibit an appreciable error caused by a leaky mushroom valve. A driver who trusts the measured value displayed by the onboard electronics and continues driving because he considers the displayed amount remaining to be reliably available, can thus be stranded with his vehicle. The mushroom valve fitted with a sealing lip improves the seal of the swirl pot, results in a more reliable display of the amount remaining by the onboard electronics, and leads to greater customer satisfaction. 
         [0016]    Embodiments of the liquid container further accommodate a mushroom valve having between one and four sealing lips. At this point, it should be noted that the sealing lip within the scope of this description of the invention should not be understood as the sealing outer edge of the valve shield or the sealing edge of the mushroom valve. Since the sealing lips must be passed successively by the liquid, the multiple sealing lips increase the seal many times. 
         [0017]    Further embodiments of the liquid container further provide that the sealing lips are configured concentrically with respect to the stem and in this respect are configured to be circular so that an isotropic seal in the container bottom plane is achieved by cooperation with a circular groove. 
         [0018]    Variants of the mushroom valve disposed in the liquid container have an elastic valve shield, whose elasticity is selected in such a manner that the sealing lip is elastically decoupled from the adjacent peripheral sealing edge of the valve shield and/or from a neighboring sealing lip. This configuration ensures that the aforesaid raising of the sealing lip of the sealing edge by solid components does not have the result that the adjacent sealing lip is also raised and thus a further sealing point is put out of action. In this respect, the elastic decoupling ensures a reliable sealing of sealing edge and the at least one sealing lip. 
         [0019]    The elastic decoupling can be achieved by selecting a sufficiently elastic material in combination with a sufficient distance between sealing lip and sealing edge or sealing lip and adjacent sealing lip. 
         [0020]    Further variants of the mushroom valve disposed in the container bottom provide that the valve shield is configured as corrugated. This configuration assists the elastic decoupling of a sealing lip from an adjacent peripheral sealing edge of the valve shield and/or and adjacent sealing lip discussed above and in this respect increase the reliability of the seal further. 
         [0021]    An example for a mushroom valve in the opening at the bottom of the liquid container can have a substantially web-shaped sealing lip. The valve shield with sealing lip(s) is thus configured as T-shaped, thus achieving a higher surface pressure on the sealing lips. By approximating the shape of the sealing lips to a T-shape, the closing force of the sealing lip can be specifically increased, independently of the seal of the adjacent sealing lips. 
         [0022]    Embodiments of the liquid container further provide that the mushroom valve located in the opening has a valve shield with a central recess. The recess edge consisting of a resilient material can then abut against the edge of the opening to be sealed and thereby form an additional sealing contact point. The recess can run symmetrically to the stem. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0023]    The present invention will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements, and: 
           [0024]      FIG. 1  shows a fuel container in a schematic side view with a swirl pot; 
           [0025]      FIG. 2  shows a section through a first mushroom valve; 
           [0026]      FIG. 3  shows a section through a second mushroom valve; 
           [0027]      FIG. 4  shows a section through a third mushroom valve; 
           [0028]      FIG. 5  shows a section through a fourth mushroom valve; and 
           [0029]      FIG. 6  shows a plan view of the bottom of the swirl pot. 
       
    
    
     DETAILED DESCRIPTION  
       [0030]    The following detailed description is merely exemplary in nature and is not intended to limit application and uses. Furthermore, there is no intention to be bound by any theory presented in the preceding summary or background or the following detailed description. 
         [0031]      FIG. 1  shows a fuel container  1  in a schematic side view. The fuel container  1  has a swirl pot  2  with a fuel pump  3  and a conically downward-tapering ascending pipe  4 , having a Venturi nozzle  5  at its lower end. Fuel passes from the swirl pot  2  to the engine via a connecting piece  6 . 
         [0032]      FIG. 2  show a mushroom valve  6  consisting of a stem  7  and a concentric valve shield  8  made of polyethylene, which is concentric thereto, in a section along the axis of symmetry S running through the stem  7 . The mushroom valve  6  serves to seal an inlet/outlet opening  11  located in the bottom  9  of a container  10 , through which the liquid can flow in or flow out from below into the container  10 . The container  10  can comprise the swirl pot  2  disposed in the interior of the fuel container  1 , shown in  FIG. 1 . 
         [0033]    The valve shield  8  has a sealing edge  12  for sealing. This sealing edge  12  surrounds the stem  7  in a circular manner and ensures that with a suitable pressure on the sealing edge  12 , the inlet/outlet opening  11  is sealed. 
         [0034]    In addition to the sealing edge  12 , the valve shield  8  has two sealing lips  13  or  14  on its underside (i.e., on the side facing the container bottom  9 ). If the sealing edge  12  is raised locally due to solid components in the liquid and is thereby leaky, the inlet/outlet opening  11  is furthermore sealed by the two sealing lips  13  and  14 . In this respect, despite the raised sealing edge  12 , a liquid flowing in the direction of the arrow P must pass through two further seals in the form of the sealing lips  13  and  14 . Since the sealing lips  13 ,  14  run concentrically to the stem  7 , the sealing arrangement shown constitutes a type of series connection of seals through which the leak rate is considerably diminished. 
         [0035]    The upper side of the valve shield  8  need not be convexly shaped but can be configured to the corrugated, as shown in  FIG. 2 . The corrugated shape assists the elastic or mechanical decoupling of the individual sealing regions. In this case, a sealing lip  13  or  14  is located below a trough  15  or  16  of the upper side of the valve shield  8 . The decoupling ensures that if a sealing edge  12  is raised by solid constituents such as, for example, sand grains, the adjacent sealing lip  13  or the further sealing lip  14  are not also raised. 
         [0036]      FIG. 3  shows another embodiment of a mushroom valve  6  which, compared to the embodiment in  FIG. 2 , has a valve shield  8  with a central recess  17 . The recess  17  is therefore in contact with the edge of the inlet/outlet opening  11 . The contact point K additionally seals the inlet/outlet opening  11 . 
         [0037]      FIG. 4  also shows an embodiment with a central recess  17  and a contact point K between the recess edge and the edge of the inlet/outlet opening  11 . The valve shield  8  is more markedly corrugated and has web-shaped sealing lips  8  or  9 . The T-shaped configuration of the valve shield  3  in this region assists the elastic decoupling of sealing edge  7  and sealing lips  8 ,  9 . 
         [0038]      FIG. 5  further shows a liquid container  10  with bottom  9 , and grooves  18  are inserted on the inside in the bottom  9 . The grooves  18  are located between the sealing edge  12  and the outer sealing lip  13 , between the sealing lips  13  and  14 , as well as between the inner sealing lip  14  and the contact point K. If one of the sealing elements  12 ,  13 , or  14  becomes leaky, because it is raised by particles, the particles sink into the grooves  18 . The probability of the particle putting the next sealing element out of action is thereby diminished. 
         [0039]    The effect of the grooves  18  persists all the longer, the larger their volume. This results from the fact that particles can accumulate in the grooves  18  with time. In this respect, the groove volumes should be selected to be as large as possible. Since no arbitrarily deep grooves  18  can be incorporated into the container bottom  9 , it is possible to select the distance of the grooves  18  from one another to be particularly small. On the other hand, the region between the grooves must be selected to be sufficiently large so that the sealing lips rest reliably thereon taking into account the relevant tolerances. 
         [0040]    The increased seal of the opening  11  by the grooves  18  is achieved as long as the grooves  18  are not completely filled with particles. However, when liquid flows into the container  10  from below, in such a case it is also possible that particles lying further above in the grooves  18  will be entrained with the inflowing fuel and floated out from the grooves. In this way, the grooves  18  should not fill completely with particles over time. 
         [0041]      FIG. 6  shows a plan view of the container bottom  9  in the area of the opening  11 . Three grooves  18   a ,  18   b ,  18   c  can be seen, these being arranged as concentric circles around the mid point M of the opening  11  in the container bottom  9 . The grooves  18   a ,  18   b , and  18   c  are spaced apart from one another relative to the line L through the mid point M. In the sealing lip contact regions  20 ,  21 ,  22 , the two sealing lips  13  and  14  and a further sealing lip abut during use. The grooves  18   a ,  18   b , and  18   c  are closed curves  19  in this case so that the sealing lips are protected along their entire circumference. The sealing edge  12  of the mushroom valve  6  comes to rest outside the outermost groove  18   c.    
         [0042]    While at least one exemplary embodiment has been presented in the foregoing summary or 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 in any way. Rather, the foregoing summary or 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 as set forth in the appended claims and their legal equivalents.