Abstract:
A lid of a fuel tank comprises a lid body constructed of a molded plastic and shaped and sized to be put in an opening formed in a wall of the fuel tank. The lid body has a first portion that is exposed to an outside of the fuel tank when the lid is put in the opening of the wall and a second portion that is exposed to an interior of the fuel tank when the lid is put in the opening of the wall. At least one of the first and second portions has a flat surface for mounting thereon external parts. The lid further comprises a through passage that extends in and through the lid body between the first and second portions. The through passage includes a first passage part terminating at the first portion, a second passage part terminating at the second portion, and a third passage part extending between the first and second passage parts to connect the same. The first and second passage parts are offset in a direction parallel with the flat surface.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates in general to lids of fuel tanks, and more particularly to the lids of a type that has external parts, such as a fuel feed pipe, an electric wiring, a fuel vapor pipe and the like, mounted thereon or therein.  
         [0003]     2. Description of the Related Art  
         [0004]     In order to clarify the task of the present invention, one conventional lid of such type will be briefly described in the following, which is disclosed in Japanese Laid-open Patent Application (Tokkaihei) 10-299599.  
         [0005]     The lid of the publication is constructed and sized to be put in an opening of an automotive fuel tank in a manner to cover the opening. The lid has a fuel feed pipe installed therethrough. In operation, fuel in the tank is led to an engine of the vehicle through the fuel feed pipe. Besides the fuel feed pipe, other external parts, such as electric wiring, fuel vapor pipe and the like tend to be mounted to the lids of the fuel tank. The wiring is used for electrically connecting an electric device in the fuel tank with an electric device arranged outside the fuel tank, and the fuel vapor pipe is used for conveying a fuel vapor produced in the fuel tank to a carbon canister installed in an engine room of an associated motor vehicle.  
       SUMMARY OF THE INVENTION  
       [0006]     Because of the external parts mounted on or in the lid, it is difficult to provide the lid with a compact or small sized structure, which causes a difficulty in installing an assembly of the fuel tank in a motor vehicle, particularly when the vehicle has a limited space for mounting the assembly. The difficulty in making the lid of such type small also appears when the lid has at its upper side a fuel vapor pipe that is raised from the lid beside another structure raised from the lid. The difficulty becomes much severe when the lid has, at its lower side exposed to an interior of the fuel tank, a fuel limited ventilation valve (viz., FLVV) through which a passage of the fuel vapor pipe is exposed to the interior of the fuel tank.  
         [0007]     Accordingly, an object of the present invention is to provide a lid of fuel tank, which can be compact in size irrespective of presence of external parts mounted thereon.  
         [0008]     In accordance with a first aspect of the present invention, there is provided a lid of a fuel tank, which comprises a lid body constructed of a molded plastic and shaped and sized to be put in an opening formed in a wall of the fuel tank, the lid body having a first portion that is exposed to an outside of the fuel tank when the lid is put in the opening of the wall and a second portion that is exposed to an interior of the fuel tank when the lid is put in the opening of the wall, at least one of the first and second portions having a flat surface for mounting thereon external parts; and a through passage that extends in and through the lid body between the first and second portions, the through passage including a first passage part terminating at the first portion, a second passage part terminating at the second portion, and a third passage part extending between the first and second passage parts, the first and second passage parts being offset in a direction parallel with the flat surface.  
         [0009]     In accordance with a second aspect of the present invention, there is provided a lid of a fuel tank, which comprises a lid body constructed of a molded plastic and shaped and sized to be put in an opening formed in a wall of the fuel tank, the lid body having a first portion that is exposed to an outside of the fuel tank when the lid is put in the opening of the wall and a second portion that is exposed to an interior of the fuel tank when the lid is put in the opening of the wall, at least one of the first and second portions having a flat surface for mounting thereon external parts; a control circuit housing integral with and mounted on the first portion, the housing containing therein a control circuit; a fuel vapor pipe integral with and mounted on the first portion at a position other than the control circuit housing; a fuel vapor passage extending in and through the lid body between the first and second portions, one end of the fuel vapor passage being connected to the fuel vapor pipe; and a fuel limited ventilation valve (FLVV) mounted to the second portion and having an inlet opening to which the other end of the fuel vapor passage is connected, wherein the fuel vapor passage comprises a first passage part terminating at the first portion, a second passage part terminating at the second portion and a third passage part extending between the first and second passage parts to connect the same, the first and second passage parts being offset in a direction parallel with the flat surface. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]     Other objects and advantages of the present invention will become apparent from the following description when taken in conjunction with the accompanying drawings, in which:  
         [0011]      FIG. 1  is a schematic illustration of an automotive fuel tank assembly to which a lid of a first embodiment of the present invention is practically applied;  
         [0012]      FIG. 2  is an enlarged side view of the lid of the first embodiment of the present invention;  
         [0013]      FIG. 3  is a plan view of the lid of the first embodiment of the present invention; and  
         [0014]      FIG. 4  is a view similar to  FIG. 2 , but showing a lid of a second embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0015]     In the following, the present invention will be described in detail with reference to the accompanying drawings.  
         [0016]     For ease of understanding, various directional terms, such as right, left, upper, lower, rightward and the like are used in the following description. However, such terms are to be understood with respect to only a drawing or drawings on which a corresponding part or portion is shown.  
         [0017]     Referring to  FIG. 1 , there is shown an automotive fuel tank assembly  100  to which a lid  10 A of a first embodiment of the present invention is practically applied.  
         [0018]     As shown, the automotive fuel tank assembly  100  generally comprises a fuel tank  50  that includes an upper wall  52  and a bottom wall  54 . The fuel tank  50  is equipped with a fuel inlet opening  56  into which a fuel feeding nozzle (not shown) of a fuel feeding machine is to be inserted for feeding the fuel tank  50  with a fuel, such as gasoline or the like.  
         [0019]     A roll over valve  58  is connected to the upper wall  52 , which functions to permit insertion of outside air into the tank  50  in a normal condition and stop dangerous outflow of the fuel to the outside through the valve  58  when, due to rollover of an associated motor vehicle or the like, the fuel tank  50  is turned upside down.  
         [0020]     Installed in the fuel tank  50  is a fuel box  60  that is mounted on the bottom wall  54 . Within the fuel box  60 , there is tightly installed an electric fuel pump  62 .  
         [0021]     Denoted by numeral  64  is a float that floats in the fuel in the fuel tank  50 . The float  64  is connected through an arm  66  to a fuel quantity sensor  68  fixed to the fuel box  60 , so that the sensor  68  senses the quantity of the fuel in the tank  50  by measuring the vertical position of the float  64 .  
         [0022]     From a top of the fuel box  60 , there extend two supporting rods  70  and  72  that are led toward the lid  10 A of the first embodiment of the present invention in an after-mentioned manner.  
         [0023]     From an outlet port of the fuel pump  62 , there extends a fuel tube  74  which is led and connected to the lid  10 A of the first embodiment, in an after-mentioned manner.  
         [0024]     From the electric fuel pump  62  and the fuel quantity sensor  68 , there extends a wire harness  76  which is led and connected to the lid  10 A, in an after-mentioned manner.  
         [0025]     Referring to  FIGS. 2 and 3 , particularly  FIG. 2 , there is shown the detail of the lid  10 A of the first embodiment of the present invention.  
         [0026]     As is seen from  FIG. 2 , for neatly receiving the lid  10 A, the upper wall  52  of the fuel tank  50  is formed with a circular opening  78 .  
         [0027]     The lid  10 A is constructed of a fiber-reinforced molded plastic and generally comprises a cylindrical upper base portion  10   a , an annular flange portion  10   b  concentrically provided by the cylindrical base portion  10   a , and a cylindrical lower base portion  10   c  projected downward from the upper base portion  10   a.    
         [0028]     It is to be noted that the portions  10   a ,  10   b  and  10   c  are integrated together to constitute a lid body of the lid  10 A, which is a single integral construction.  
         [0029]     As is seen from  FIG. 2 , upon setting on the upper wall  52  of fuel tank  50 , the cylindrical lower base portion  10   c  of the lid  10 A is neatly received in the circular opening  78  of the upper wall  52  having the annular flange portion  10   b  seated on a peripheral edge of the opening  78  of the upper wall  52 .  
         [0030]     For tightly and detachably fixing the lid  10 A to the upper wall  52 , a lock ring  80  put on the annular flange portion  10   b  is engaged with a grooved annular bank (not shown) formed on the upper wall  52  around the circular opening  78 .  
         [0031]     In the first embodiment  10 A of the present invention, the following five plastic parts  82 ,  84 ,  86 ,  88  and  90  are integrated to the lid  10 A. That is, the above-mentioned portions  10   a ,  10   b  and  10   c  and the following five parts  82 ,  84 ,  86 ,  88  and  90  are all integrated to constitute a single plastic unit that is the lid  10 A.  
         [0032]     Denoted by numeral  82  in  FIG. 2  is a plug housing that is integral with a side portion of a next-mentioned housing  84  for a control circuit. For ease of understanding, the detail of the plug housing  82  will be described after the description of the control circuit housing  84 .  
         [0033]     The housing  84  for the control circuit is integrally mounted on a flat surface of the upper base portion  10   a . As is seen from the drawing, wires  76   a  are led from the wire harness  76  to the control circuit in the housing  84 . Each of the wires  76   a  is of a plate metal type. Denoted by numeral  77  is a connector that is mounted to the cylindrical lower base portion  10   c  to detachably connect the wires  76   a  and the wire harness  76 . As shown, the wires  76   a  extend in and through the lid  10 A, more specifically, through the cylindrical upper base portion  10   a  and the cylindrical lower base portion  10   c.    
         [0034]     As shown in  FIG. 3 , the control circuit housing  84  is semicircular in shape when viewed from the above.  
         [0035]     Referring back to  FIG. 2 , the above-mentioned plug housing  82  has therein terminal elements (not shown) to which wires (not shown) extending from the control circuit in the housing  84  are connected. The terminal elements may be of a lead wire type, connector type or land type.  
         [0036]     Detachably connected to the plug housing  82  is a socket housing  83  to which a wire harness  83   a  from an engine control unit, a power source (viz., battery) and the like is connected.  
         [0037]     In  FIG. 2 , denoted by numeral  86  is a fuel vapor pipe that is integral with and raised from a peripheral portion of the cylindrical upper base portion  10   a . As will be described in detail hereinafter, an interior  86   a  of the fuel vapor pipe  86  is communicated with the interior of the fuel tank  50  through a zig-zag passage  12  that extends in and through the lid body of the lid  10 A and an after-mentioned fuel limited ventilation valve (viz., FLVV)  88 .  
         [0038]     Although not shown in the drawings, from the fuel vapor pipe  86 , there extends a fuel vapor tube to a carbon canister that is installed in an engine room of the vehicle. That is, a fuel vapor produced in the fuel tank  50  is led to and adsorbed by the carbon canister, and upon operation of an associated engine, the vapor is released from the canister and fed to the intake system of the engine to be burnt.  
         [0039]     As shown in  FIG. 3 , an upper horizontal part of the fuel vapor pipe  86  extends radially outward beyond the periphery of the lid  10 A.  
         [0040]     Referring back to  FIG. 2 , denoted by numeral  88  is the fuel limited ventilation valve (FLVV) that has an upper end connected to the cylindrical upper base portion  10   a . An upper end of the above-mentioned supporting rod  72  supports the bottom wall of the valve  88  through a spring member (not shown). Like this, an upper end of the other supporting rod  70  supports the lower base portion  10   c  of the lid  10 A through a spring member (not shown).  
         [0041]     The fuel limited ventilation valve (viz., FLVV)  88  functions to shut off the passage of the fuel vapor pipe  86  when, under fuel feeding by the fuel feeding machine, the amount of the fuel in the fuel tank  50  reaches a predetermined upper limit level.  
         [0042]     As is understood from  FIG. 2 , for the fluid connection between the fuel vapor pipe  86  and the fuel limited ventilation valve (viz., FLVV)  88 , a zig-zag passage  12  is formed in the lid body of the lid  10 A.  
         [0043]     The zig-zag passage  12  comprises an upper passage part  12   a  that vertically extends in the lid body to be mated with the passage  86   a  of the fuel vapor pipe  86 , a lower passage part  12   b  that vertically extends in the lid body to be mated with a center passage of the fuel limited ventilation valve  88 , and an intermediate passage part  12   c  that horizontally extends in the lid body to connect the upper and lower passage parts  12   a  and  12   b.    
         [0044]     It is to be noted that such zig-zag shape of the passage  12  allows the fuel vapor pipe  86  to take a peripheral position of the circular lid body of the lid  10 A. In other words, as is seen from  FIG. 3 , even if the housing  84  for the control circuit occupies a considerably larger space on the upper base portion  10   a  of the lid  10 A, setting the fuel vapor pipe  86  on the lid  10 A is easily made.  
         [0045]     Referring back to  FIG. 2 , denoted by numeral  90  is a fuel pipe that is illustrated by a dotted line. The fuel pip  90  is integrally mounted on the cylindrical upper base portion  10   a  beside fuel vapor pipe  86 . Although not well shown in the drawings, between a lower end of the fuel pipe  90  and the above-mentioned fuel tube  74 , there extends a fuel passage  90   a  (illustrated by a dotted line) that is formed in and through the cylindrical upper base portion  10   a  and the cylindrical lower base portion  10   c . For detachable connection between the fuel tube  74  and the fuel passage  90   a , a connector (not shown) is used. As shown, the fuel passage  90   a  extends perpendicular to a major flat surface of the lid  10 A. That is, in the illustrated example, the fuel pipe  90  is positioned just above an upper end of the fuel tube  74 .  
         [0046]     As will be understood from  FIG. 1 , under operation of the associated motor vehicle, the electric fuel pump  62  is controlled by the control circuit installed in the housing  84 , which circuit processes various information signals fed thereto through the wire harness  83   a . Due to operation of the pump  62 , the fuel is fed to the engine through the fuel tube  74 , the fuel passage  90   a  formed in the lid  10 A, the fuel pipe  90  raised from the lid  10 A and a fuel carrying tube (not shown). Lowering of the float  64  due to reduction of the fuel in the fuel tank  50  is sensed by the sensor  68  and this sensed information on quantity of the fuel is led to the control circuit installed in the housing  84  through the wire harness  76 . The roll over valve (viz., ROV)  58  compensates a pressure reduction in the fuel tank  50  by permitting insertion of outside air into the tank  50 . However, if, due to turning over, rollover or the like of the vehicle, the fuel tank  50  becomes severely inclined or turned up side down, the valve  58  shuts off the fluid communication between the interior of the tank  50  and the outside of the tank  50 . Fuel vapor produced in the fuel tank  50  is led through the fuel limited ventilation valve (FLVV)  88 , the fuel vapor pipe  86  and the fuel vapor tube (not shown) to the carbon canister installed in the engine room. When, under fuel feeding by the fuel feeding machine, the amount of the fuel reaches a predetermined upper limit, the fuel limited ventilation valve (FLVV)  88  shuts off the passage of the fuel vapor pipe  86 .  
         [0047]     Referring to  FIG. 4 , there is shown a lid  10 B of a second embodiment of the present invention.  
         [0048]     Since the lid  10 B of this second embodiment is similar in construction to the above-mentioned lid  10 A of the first embodiment, only parts or portions that are different from those of the first embodiment  10 A will be described in detail in the following.  
         [0049]     In this second embodiment  10 B, the zig-zag passage  12 ′ comprises an upper passage part  12 ′ a  that vertically extends in the lid body of the lid  10 B to be mated with the passage  86   a  of the fuel vapor pipe  86 , a lower passage part  12 ′ b  that vertically extends in a body of the fuel limited ventilation valve (FLVV)  88  to be mated with a center passage of the valve  88 , and an intermediate passage part  12 ′ c  that horizontally extends in the body of the valve  88  to connect the upper and lower passage parts  12 ′ a  and  12 ′ b . That is, in this embodiment  10 B, a part of the zig-zag passage  12 ′ is defined by the body of the fuel limited ventilation valve  88 . If desired, the intermediate extending passage part  12 ′ c  may be a groove that is defined by either one of the lower surface of the cylindrical upper base portion  10   a  and an upper surface of the body of the fuel limited ventilation valve  88 .  
         [0050]     As is described hereinabove, in accordance with the present invention, there is used a zig-zag passage  12  or  12 ′ for connecting the fuel vapor pipe  86  and the fuel limited ventilation valve (viz., FLVV)  88 . The zig-zag passage  12  or  12 ′ comprises the vertically extending upper passage part  12   a  or  12 ′ a , the vertically extending lower passage part  12   b  or  12 ′ b  and the horizontally extending intermediate passage part  12   c  or  12 ′ c . Due to provision of the horizontally extending intermediate part  12   c  or  12 ′ c  that has a length of “D”, the position of the fuel vapor pipe  86  can be offset toward the periphery of the lid body of the lid  10 A or  10 B by the distance “D”. This means that an upper flat area of the upper base portion  10   a  of the lid  10 A or  10 B can have a sufficiently large space for mounting thereon various external parts. As is seen from  FIG. 3 , even when the control circuit housing  84  occupies a marked space on the upper flat area of the lid  10 A or  10 B, positioning of the fuel vapor pipe  86  on the lid  10 A or  10 B is easily made for the above-mentioned reason. In other words, the control circuit housing  84 , the fuel vapor pipe  86  and the fuel pipe  90  have a higher freedom to take various layout on the upper base portion  10   a  of the lid  10 A or  10 B.  
         [0051]     In the following, modification of the present invention will be described.  
         [0052]     First, if desired, in place of the fuel limited ventilation valve  88 , the lid  10 A or  10 B may be provided with the roll over valve (viz., ROV)  58 .  
         [0053]     Second, if possible, an outer surface of the lid  10 A or  10 B may be coated with an oil proof plastic layer.  
         [0054]     Third, the plug housing  82  may be a separate member. In this case, the plug housing  82  is secured to the control circuit housing  84  by means of bolts or the like.  
         [0055]     fourth, if desired, the two supporting rods  70  and  72  may be secured to the lid  10 A or  10 B. In this case, the fuel box  60 , the fuel pump  62  and the mechanism  66  and  68  of the float  64  constitute a so-called in-tank module that hangs down into the fuel tank  50  from the lid  10 A or  10 B. Furthermore, if desired, a pressure regulator for regulating a discharge pressure of the pump  62 , a fuel filter for filtering the fuel discharged from the pump  62 , and a suction filter for filtering the fuel fed to the pump  62  may be installed in the in-tank module.  
         [0056]     The entire contents of Japanese Patent Application 2004-208532 filed Jul. 15, 2004 are incorporated herein by reference.  
         [0057]     Although the invention has been described above with reference to the embodiments of the invention, the invention is not limited to such embodiments as described above. Various modifications and variations of such embodiments may be carried out by those skilled in the art, in light of the above description.