Abstract:
A baffle unit for operative cross mounting within a liquid fuel tank of an automotive vehicle to attenuate wave action of the liquid fuel within the tank during vehicle operation and thereby prevent or reduce the impact of such fluid motion against the wall of the tank and thereby eliminate or reduce harshness, vibration and noise. The baffle unit comprises a frame with latticed work defining open side faces encapsulating a mat of fiberglass filaments caged therein and having a porosity for the passage of waves of liquid fuel therethrough to attenuate the waves while trapping particles of fuel-contaminating foreign matter The frame is supported for telescoping action in a carrier. Helical end springs urge the frame to an outer position against the interior walls of the tank after the unit is compressed to collapse the unit to allow its easy insertion into the tank. The baffle unit can readily be used as an additional fluid filter by the hydraulic connection of the interior of the frame member with the intake of the fluid pump operatively mounted within the tank.

Description:
[0001]    This invention relates in general to fuel wave baffling fuel tanks supplying liquid fuel to internal combustion engines powering vehicles and more particularly to new and improved fuel wave baffle construction for wave attenuation and resultant noise, vibration and harshness abatement in vehicles when operatively mounted within their fuel tanks and further to such baffles capable of fuel filtering prior to being pumped from the tank.  
           [0002]    Prior to the present invention, liquid fuel tanks for automotive vehicles have been designed with various constructions to reduce noise, vibration and ride harshness, frequently referenced as NVH, generated by the motion of fuel impacting the walls of the tank during vehicle operation. For example many vehicles have fuel tanks molded from plastics and have fixed baffles directly molded therein. Other tanks have been designed with discrete internal wave baffles and others with special filter units to filter engine fuel prior to such fuel being pumped from the tank for combustion by an internal combustion engine powering the vehicle. Examples of such constructions can be found in the U.S. Pat. No. 5,850,933 issued Dec. 22, 1988 to Pazik for Molded Gas Tank With Internal Baffle; U.S. Pat. No. 6,138,859 issued Oct. 31, 2000 to Aulph et al for Fuel Tank Assembly; U.S. Pat. No. 4,974,743 issued Dec. 5, 1990 to Sasaki for Fuel Tank With Noise Suppressing Arrangement and U.S. Pat. No. 6,098,599 issued Aug. 8, 2000 to Muldoon et al for System for Delivering Fuel to A Motor Vehicle and Related Method  
           [0003]    While the prior constructions generally attain their objectives, they do not meet new and higher standards for optimal liquid fuel motion damping and attendant control of fuel wave generated noises, vibration and harshness transmitted into the vehicle. Moreover, they are not capable of providing additional new and improved filtration of fuel to improve operation of fuel pump units supplying the engine with fuel from the tank.  
           [0004]    In contrast to the prior art constructions, the present invention effectively reduces or eliminates such noise, vibration and harshness problems and meets higher standards to efficiently moderate fuel motion within the tank to reduce or eliminate consequential NVH problems. Optimized vibration, noise and vibration reduction is accomplished in the present invention with a new and improved wave damping baffle unit which can be readily fabricated from light weight and durable materials and components that incorporates fuel media permeable and wave damping media which can be readily installed in a fuel tank and have long service life. Moreover, this wave-damping unit can be further and advantageously utilized to provide superior filtering of foreign matter from the liquid fuel contained within the fluid tank to eliminate contaminant damage to components of the fuel delivery system.  
           [0005]    An object, feature and advantage of the present invention is to provide a new and improved fuel wave baffle construction that can be readily produced and easily and straightforwardly introduced into a fuel tank of an automotive vehicle and subsequently located therein at a predetermined and permanent position.  
           [0006]    Further it is an object of this invention to provide a new and improved combination fuel wave baffle and filter unit operatively mounted in a liquid fuel tank of an automotive vehicle having internal flow controlling medium providing optimized abatement of fuel motions such as waves of fuel occurring during vehicle operation in addition to improved filtering of the liquid fuel prior to being pumped to the internal combustion engine of the vehicle.  
           [0007]    Another object feature and advantage of the present invention is to provide a new and improved liquid fuel wave abating baffle unit having flow controlling media of a porosity imparting improved control of fuel flow therethrough and improved management of fluid motion such as fuel wave or “splash” action of liquid fuel within a tank during vehicle operations.  
           [0008]    An additional object, feature and advantage of the present invention is to employ the fuel wave controlling media of fuel wave baffle unit in a liquid fuel tank for an automotive vehicle for improved fuel filtering to prevent foreign matter from being delivered to the fuel pump and other components such as pressure regulating valves and fuel injectors operatively associated with the combustion chambers of the vehicle engine.  
           [0009]    The baffle and filter unit of one preferred embodiment of the invention operates in parallel with the conventional fuel pump or fuel sender unit filter. The filtering media of the baffle and filter unit preferably has fine filtration capability designed for optimizing the separation of foreign matter from the fuel to thereby extend the life cycle of the fuel pump as well as the fuel pressure regulator and other fuel delivery components susceptible of being contaminated by such foreign matter. The media used in the baffle and filter construction preferably comprises a non-woven mat of 3-5 micron diameter filaments of fiberglass to abate the waves of fuel passing therethrough and to provide a substantial increase in overall surface area and dirt capacity (life time) of filtration and supplementing existing internal filters while reducing the need for external filtration systems.  
           [0010]    The baffle and the baffle and filter units may be conveniently installed through the fuel pump module opening provided in the tank. This can be readily accomplished since the units employ a pair of basic retainer components that are spring loaded and can be selectively and telescopically compressed together to reduce the dimensions thereof. This size reduction allows the unit to be easily inserted through the opening in the fuel tank. After initial insertion and subsequent positioning in the tank, the components of the unit are released so that they automatically expand under spring loading for secure spring biased retention of the unit within the fuel tank at a predetermined home position. 
       
    
    
       [0011]    These and other objects advantages and features of the present invention will become more apparent from the following detailed description and drawing in which:  
         [0012]    [0012]FIG. 1 is a pictorial view of a liquid fuel tank for an automotive vehicle with an upper wall portion thereof partially broken away;  
         [0013]    [0013]FIG. 1 a  is a partial sectional view taken generally along sight lines  1   a - 1   a  of FIG. 1;  
         [0014]    [0014]FIG. 2 is a pictorial view of the baffle unit utilized in the fuel tank of FIG. 1 with baffle media partially cut away;  
         [0015]    [0015]FIG. 2 a  is a pictorial view of a portion of the baffle unit of FIG. 2 
         [0016]    [0016]FIG. 3 is an enlarged cross sectional view of a portion of the baffle unit of FIG. 2 as installed in the fuel tank and taken generally along sight lines  3 - 3  of FIG. 1;  
         [0017]    [0017]FIG. 4 is a pictorial view similar to the pictorial view of FIG. 1 illustrating an embodiment of the inventor;  
         [0018]    [0018]FIG. 5 is a pictorial view of the baffle unit of FIG. 4 partially broken away to illustrate interior details thereof;  
         [0019]    [0019]FIG. 6 is a sectional view of the baffle unit of FIG. 5 installed in the fuel tank of FIGS. 1 and 4 and further modified to illustrate another embodiment of the invention.  
         [0020]    [0020]FIG. 7 is a sectional view taken generally along sight lines  7 - 7  of FIG. 6; 
     
    
     DETAILED DESCRIPTION  
       [0021]    Turning now in detail to the drawings there is shown in FIG. 1 a shell-like liquid fuel tank  10  strapped or otherwise mounted on a support  12  of an automotive vehicle powered by an internal combustion engine, not shown. The tank  10 , preferably blow molded from a suitable plastic material, has a fuel inlet filler tube  14  and provides a container for the effective storage and on-board transport of liquid fuel such as gasoline for delivery to and combustion by the vehicle engine. More particularly, the fuel is supplied to the engine by means of a fuel sender or fuel pump module  16  that is operatively supported in the tank for operation by a removable cover  18  closing an access opening  20  formed in the upper wall  22  of the tank.  
         [0022]    The fuel pump module  16  is a conventional unit and includes an internal fuel pump  24  operatively connected to an adjacent pressure regulator  26  that operatively regulates the pressure of the fuel discharged by the pump  24 . This discharged fuel is fed through line  28  external filter  30  and then through line  32  to the combustion chamber charging mechanisms, not illustrated. Excess fuel from the fuel pressure regulator is filtered by filter  30  and then fed back into an internal reservoir  34  through line  36  for subsequent delivery to the engine as is known in the art.  
         [0023]    The fuel pump module  16  further incorporates a primary fuel filter  40  operatively connected to an intake  42  of the pump and strategically located placed at a low point in the tank so that fuel can be effectively drawn from the tank through the minute straining voids of the filtering media of the filter. This filter effectively catches and traps foreign matter downstream of the pump and prevents foreign matter from entering the pump, pressure regulator as well as other components that receive fuel from the pump.  
         [0024]    To dampen the wave action or “sloshing” or other motion of the liquid fuel in the tank and against the wall thereof, the present invention provides a new and improved fuel wave baffle unit or assembly  46 . The baffle assembly is a discrete, separately built unit, which is readily adaptable to various tank constructions, and particularly those formed of plastics such as by blow molding. The baffle assembly is shown in better detail in FIGS. 2 and 3 and comprises an elongated, shell-like carrier  48 . The carrier is molded from Acetal or other suitable plastic material and has laterally spaced sidewalls  50  extending upwardly from a flattened bottom wall  52  and closed at opposite ends by end walls  54 .  
         [0025]    The carrier  48  is further defined by an opened upper side to provide a cradle or receiver for a cage-like frame member  55  containing a fibrous fuel flow control media  56 . The frame member  55 , molded from polyethylene or other suitable plastics, is operatively mounted in the carrier for telescopic movement between fully compressed or fully extended positions. More particularly the frame member  55  comprises of a pair of elongated side frame members  58  of Acetal each having lattice work defining a flattened side face  60  with open fluid-flow windows. The side frame members have peripheral edge walls  62 . These edge walls align and project toward one another for contact and permanent connection at their interfacing terminal edge surfaces. The side frame members  58  when joined provide a surrounding retainer for the fuel porous media  56  completely filling the retainer and define a media unit  59  operative to attenuate the waves of fuel as the fuel flows therethrough on wave movement from one end of the tank toward the other. The media unit may be made in any suitable shape and from any suitable materials such as a pillow-like mat of non-woven fiberglass filaments or fibers covered by a scrim  63  of polyester or other suitable material.  
         [0026]    [0026]FIGS. 2 and 3 best illustrate the telescopic features of the baffle assembly  46  and show the media unit  59  operatively seated within the shell-like carrier  48  and extending upwardly from the open top end thereof. A pair of helical biasing springs  68 , only one of which is shown in FIG. 3, are operatively disposed between the carrier and the filter unit at opposite ends of the unit and near the end walls  54  of the carrier. These springs provide the force to urge the two components of the baffle assembly from one another and into an expanded position and into close-fitting engagement with the inner surfaces of the upper and lower wall portions of the fuel tank  10 . This construction and fit is best shown in FIG. 3 in which helical spring  68  is seated on a retainer post  70  projecting upwardly from the bottom wall  52  of carrier  48 . The upper end of the spring  68  is received in the downwardly extending spring pocket  72  formed in the ends of the filter assembly and seats on the upper pocket closure wall  74  thereof.  
         [0027]    To maintain the baffle assembly  46  operatively together so that the components can be telescoped between opened and closed position without coming apart, both sides of the of the filter assembly are provided with outwardly projecting followers  78  which are adapted to ride in guide and retainer slots  80  that extend vertically in the side walls  50  of the carrier  48 . The contact of these followers with the upper extent of their associated slots provides the telescopic outer travel limit of the components of the baffle assembly.  
         [0028]    The bottom wall  84  formed by the lower edge walls of the frame member  55  of the media unit  59  has a pair of laterally-spaced retainer ears  86  projecting therefrom. These ears are designed to receive a fixed retainer ear  88  extending upwardly from the bottom wall of the carrier and all of these elements are suitably holed so that when aligned can receive a retainer pin  90  therethrough. This pin releasably keeps the media unit  59  and carrier  48  in a telescopically contracted condition.  
         [0029]    With this construction, the components of the baffle assembly  46  can be collapsed to a full telescoped position and then retained in this condition by use of the retainer pin  90 . The collapsed baffle assembly, retained in a telescoped state and reduced in size, can be manually or otherwise inserted through the enlarged circular access opening  20  in the top of the tank and positioned therein between the pairs of spaced locator and retainer bumps  92  and  94  formed in the top and bottom wall portion of the tank. The telescoped assembly can then be released by removing pin  90  such as with the use of suitable tooling and allowed to expand under spring loading so that it is trapped in a stabilized and predetermined position within the tank between the bumps as diagrammatically illustrated in FIG. 1 a.    
         [0030]    Baffle operation most effectively takes place when the tank has larger volumes of liquid fuel therein and when waves of liquid fuel are generated as the vehicle is driven. Such waves may travel from one end of the tank  10  toward the other and fronting the baffle assembly. These waves will be effectively modulated or eliminated as the liquid fuel passes thorough the cross-tank barrier provided by the baffle unit and particularly through the media carried by the baffle so that the walls of the tank are not excessively impacted by moving waves of fuel. Such fluid motion control accordingly reduces or effectively eliminates fuel wave induced vehicle ride harshness, vibration and noise to optimize vehicle operation and passenger comfort.  
         [0031]    The baffle assembly can further be effectively utilized to augment the filtering of fuel provided by the fuel filter  40 . In FIG. 4 for example, the fuel tank  100  has a fuel sender or pump module  112  including internal liquid fuel pump  114  operative to draw fuel from a low point in the center of the tank through filter  116  via the interconnecting pump intake  118  as in the FIG. 1 construction. To provide additional fuel filtering capacity a fuel wave attenuating or baffle assembly substantially the same as the assembly  46  of FIGS.  1 - 3  can be utilized.  
         [0032]    More particularly a combination fuel wave baffle and fluid filter assembly  120  extending across the fuel tank as in the FIG. 1 construction is utilized. The baffle and filter assembly  120  and fuel pump intake  118  are slightly modified as compared to the FIG. 1 construction with appropriate fluid connections added for coupling to a flexible fuel conducting hose  122  extending therebetween. This construction is advantageously employed to hydraulically connect the interior of the baffle and filter assembly  120  with the fuel pump intake  118  of the fuel pump so that additional fuel may be filtered and transmitted into the pump and then pumped into the fuel delivery components downstream of the pump.  
         [0033]    The wave baffle and fluid filter assembly  120  comprises open-faced and cage-like retainer or frame member  124  that encapsulates media  126  which preferably is the same as the media  56  of FIGS.  1 - 3  above. The frame and its captured media define the media unit  130  that not only damps fluid wave action but also further operates to filter foreign matter from the liquid fuel prior to delivery to the pump. The media  126  comprises a mat  132  of 3-5 micron diameter fiberglass filaments encased by a scrim  134  or other suitable covering.  
         [0034]    The retainer or frame member  124  is basically the same as the retainer of FIGS.  1 - 3  in so far as material and general construction are concerned and has opposing open sides. These sides are defined by the lattice work of intersecting strips of polyethylene providing opposing side windows allowing the fuel to flow through the media while damping the wave action of the fuel to minimize impact of the waves on the wall of the fuel tank. The strips defining these windows can be hermetically or otherwise sealed to the scrim to ensure that the fuel does not go around or bypass the media in the frame thereby compromising or otherwise detracting from the damping characteristics or fuel filtering capability of the media. The media further operates as a wick or sponge, retains fuel in the minute voids thereof, and therefore holds fuel within the confines of the frame member  124 .  
         [0035]    The media unit  130  is preferably an upper member of the baffle and filter assembly  120  and is operatively mounted for telescopic movement with respect to a lower carrier  134 . As in the FIG. 1 construction the lower carrier is configured as an elongated shell with an open top that telescopically receives the media unit  130 . A pair of helical springs  136  mounted on retainers  137  formed on the lower wall of the carrier extending upwardly into endmost spring pockets  138  in the frame of the media unit and seat on the closure wall thereof as best shown in FIG. 6.  
         [0036]    The two spring biased telescoping components i.e. the media unit  130  and carrier  134  are operatively maintained in their sliding telescopic relationship by followers  139  extending from the sides of the media unit which ride in the vertical slots  140  formed in the sides of the carrier.  
         [0037]    The open-faced frame member  124  of the media unit is further modified to have an opening  141  in outboard side thereof that receives a fluid conducting and connector tube  142 . This connector tube is securely fixed to a solid portion of the side wall provided by one of the outboard plastic strips of the frame member and is designed to extend from the interior of the media to an external head portion  144  and thereby into fluid tight connection with the flexible hose  122  that operatively connects into the pump intake with a quick connect fitting. With this construction the media unit operatively connects into the pump intake  118  so that the pump  114  can be further supplied with additional filtered fuel to thereby reduce fuel starvation by the pump. The connector tube  142  configuration shown in FIG. 5 has an inner most end that may be perforated and terminates within the media and within a fuel containment portion  148  provided by the tray-like bottom of the frame member  124  to augment fuel availability when the tank has a low level of fuel. This construction can be replaced by a straight tube or other suitable configuration.  
         [0038]    [0038]FIGS. 6 and 7 illustrate the employment of a third fuel filter  150  outside of the baffle unit and seated at a low point in the tank  100  may be provided to wick up fuel therefrom. This latter filter hydraulically connects to a suitable valve unit  151  mounted in the interior of the media unit  130  of the wave baffle and filter by fuel conducting tube  152 . The valve unit is normally open and is operative to allow filtered fluid to enter from the media which is then fed into the nose  122  connected into the pump. However, when the fuel in the tank becomes very low, the valve closes with respect to the baffle unit such as by operation of a float and fuel is then supplied to the nose only through the filter  150 .  
         [0039]    With this construction, the fuel wave attenuation baffle can be effectively utilized to filter foreign matter from the fuel prior to the fuel being pumped to the fuel delivery system components down stream of the pump. This importantly adds additional in-tank filtering capacity and insures that the pump is adequately supplied with fuel even when the fuel quality has been compromised by particulate of foreign matter. Moreover, with this invention the external filter  152  in the delivery line lead from the tank may potentially be eliminated. Furthermore, the units of FIGS.  4 - 7  may be telescoped and maintained in closed position by the closure pin construction which is like the pin and retainer construction of FIG. 2 a  and then easily installed through the opening in the top of the tank in a manner similar to the method disclosed in connection with FIGS.  1 - 3  with attention being duly paid to the hose hook up between the baffle and filter unit and the pump intake. A conventional snap in or other type quick connect may be used to connect the hose  122  to the pump intake to augment assembly of the wave baffle and filter to the pump.  
         [0040]    The invention may be varied in many obvious ways to those skilled in the art and such variations are within the scope and spirit of the following claims: