Abstract:
A fuel filling port structure of a fuel tank is provided in which a lid housed in the port structure is biased towards a closed position when a fuel supply nozzle is not inserted, and moved to an open position when the fuel supply nozzle is inserted. Lid locking mechanisms are disposed in the port structure which lock the lid in the closed position or unlock the lid so as to be movable to the open position corresponding to the insertion of the fuel supply nozzle.

Description:
TECHNICAL FIELD  
       [0001]     The present invention relates to a fuel filling port structure of a fuel tank in which a lid housed in the fuel filling port structure is biased toward a closed position, and the lid is moved to an open position when a fuel filling nozzle is inserted.  
       BACKGROUND OF THE INVENTION  
       [0002]     To speedily perform a fuel filling operation carried out in racing of motorcycles, in Japanese Patent Document JP-UM-A-3-27869, there has been known the fuel filling port structure of a fuel tank which operates a lid such that the lid is pushed downwardly to open a fuel filling port in response to a pushing manipulation of a fuel supply device to the fuel filing port and the lid closes the fuel filling port by simply removing the fuel supply device from the fuel filling port.  
         [0003]     Here, the fuel filling port structure of a fuel tank disclosed in the above-mentioned Japanese Patent Document is configured such that the lid is biased by a spring toward a side that the fuel filling port is closed and hence, even when a pushing force acts on the lid due to an object other than the fuel supply device, the lid opens the fuel filling port.  
         [0004]     The present invention has been made in view of the above-mentioned circumstances and it is an object of the present invention to provide a fuel filling port structure of a fuel tank which can prevent the opening of a fuel filling port due to an object other than a fuel supply device.  
       SUMMARY OF THE INVENTION  
       [0005]     To achieve the above-mentioned object, the invention provides a fuel filling port in a fuel tank for receiving a fuel supply nozzle therein. The fuel filling port includes a port structure formed on the fuel tank for receiving fuel into the fuel tank, a lid disposed in the port structure and being movable between an open position and a closed position in response to insertion of the fuel supply nozzle, the lid being biased to the closed portion, and a plurality of lid locking mechanisms disposed in the port structure for locking the lid in the closed position when the fuel supply nozzle is not inserted, and for unlocking the lid when said fuel nozzle is inserted.  
         [0006]     Further, a second characteristic of the invention resides in that the lid locking mechanisms are mounted on the fuel tank at a periphery of the port structure.  
         [0007]     A third characteristic of the invention resides in that wherein the lid locking mechanisms include a rotary shaft, a cam fixed to a first end of the rotary shaft such that the cam is rotated when the fuel supply nozzle is inserted, and an engaging member fixed to a second end of the rotary shaft such that the engaging member is rotated when the cam is rotated, said rotation of the engaging member unlocking said lid.  
         [0008]     A fourth characteristic of the invention resides in that a spring is disposed between the rotary shaft and the fuel tank in order to bias the rotary shaft to a position in which a portion of the cam projects towards a center of the port structure and in which the engaging member locks the lid.  
         [0009]     Further, a fifth characteristic of the invention resides in that the lid locking mechanisms are mounted at three portions of a periphery of the port structure in an equidistantly spaced-apart manner in the circumferential direction.  
         [0010]     According to the invention, when the manipulation to push the fuel supply device into the fuel filling port is performed, the lid is released from a closed position in which the lid is in locked by the lid locking mechanisms, and the fuel filling port can be opened by pushing down the lid. On the other hand, even when a pushing force is applied to the lid using an object other than the fuel supply device, the lid is held in the closed position by the lid locking mechanism and hence, there is no possibility that the lid is operated to open the fuel filling port. That is, the opening of the fuel filling port by an object other than the fuel supply device can be prevented.  
         [0011]     Further, according to the invention, since the fuel supply devices are brought into contact with the lid locking mechanisms which are mounted on the fuel tank at three portions of the fuel filling port in an equidistantly spaced-apart manner in the circumferential direction, it is possible to support the fuel supply device in a stable manner at the time of performing the manipulation to push the fuel supply device into the fuel filling port. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]     The advantages of the invention will become apparent in the following description taken in conjunction with the drawings, wherein:  
         [0013]      FIG. 1  is a longitudinal cross-sectional side view of a portion of a fuel tank and a fuel supply device according to the invention;  
         [0014]      FIG. 2  is a plan view of the fuel tank taken from the direction of line  2 - 2  in  FIG. 1 ;  
         [0015]      FIG. 3  is an enlarged longitudinal cross-sectional view of a lid locking mechanism according to the invention;  
         [0016]      FIG. 4  is a longitudinal cross-sectional side view corresponding to  FIG. 1  in a state that a fuel supply device is inserted into a fuel filling port according to the invention;  
         [0017]      FIG. 5  is a cross-sectional view taken along line  5 - 5  in  FIG. 4 ;  
         [0018]      FIG. 6  is a longitudinal cross-sectional side view corresponding to  FIG. 1  in a state that the fuel supply device is further inserted into the fuel filling port from a state of  FIG. 4 ; and  
         [0019]      FIG. 7  is a longitudinal cross-sectional side view corresponding to  FIG. 1  in a state that the fuel supply device is inserted into a deepest position of the fuel filling port according to the invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0020]     First of all, in  FIG. 1  and  FIG. 2 , a circular opening portion  13  is formed in an upper portion of a tank body  12  which constitutes a part of a fuel tank  11 , a support ring  14  is connected to the tank body  12  by welding at a periphery of the opening portion  13 , and a mouthpiece  15  is connected to the support ring  14  by fastening. The mouthpiece  15  is integrally formed of a cylindrical portion  15   a  which defines a fuel filling port  16  therein and a flange portion  15   b  which projects from a first end portion of the cylindrical portion  15   a  in the radially outward direction. The flange portion  15   b  which interposes an annular sealing member  17  between the support ring  14  and the flange portion  15   b  is connected to the support ring  14  using a plurality of bolts  18  by fastening.  
         [0021]     At three positions which are arranged in an equidistantly spaced-apart manner in the circumferential direction of the cylindrical portion  15   a  of the mouthpiece  15 , a second end portion of guide shafts  19 , which extend in parallel to an axis of the cylindrical portion  15   a , are threadedly engaged with the first end of the cylindrical portion  15   a  in a state that the first end of the cylindrical sleeve portion  15   a  extends into the inside of the tank body  12 . Here, a disc-shaped restricting plate  20  is fixed to a first end of the guide shafts  19 . Flange portions  19   a , which are brought into contact with an upper surface of the restricting plate  20  are respectively integrally formed at the portion of guide shaft  19  which penetrates the restricting plate  20 . Washers  21 , which allow the guide shafts  19  to pass therethrough, are brought into contact with a lower surface of the restricting plate  20 , and pins  22 , which are engaged with washers  21  from below, respectively penetrate the guide shafts  19 .  
         [0022]     The fuel filling port  16  can be closed or opened by a lid  25  which is stored in the inside of the tank body  12 . A ring-shaped annular projection  15   c  for closing the fuel filling port  16  by allowing an annular sealing member  26 , which is mounted on an outer periphery of the lid  25  to be seated thereon, is integrally mounted on the mouthpiece  15  in a state that the annular projection  15   c  projects in the radially inward direction from an inner surface of the first end portion of the cylindrical portion  15   a . The respective guide shafts  19  penetrate the lid  25 . By guiding the lid  25  with the respective guide shafts  19 , the lid  25  can be vertically moved between an upper position at which the lid  25  closes the fuel supply port  16  and a lower position at which the lid  25  is brought into contact with the restricting plate  20 . Further, at portions corresponding to the respective guide shafts  19 , which are arranged between the restricting plate  20  and the lid  25 , return springs  27  are mounted which bias the lid  25  in the upward direction, that is, in the direction that the fuel filling port  16  is closed.  
         [0023]     The lid  25  is operated to open the fuel filling port  16  by the pushing manipulation of the fuel supply device  28 , which includes the fuel supply nozzle  29 . The fuel supply device  28  includes the fuel supply nozzle  29 , which is formed into a bottomed cylindrical shape having a first end thereof closed in a state that the closed end of the fuel supply nozzle  29  is brought into contact with the lid  25 . The fuel supply nozzle  29  also has a side wall which is arranged close to the first end thereof, in which a plurality of valve holes  30  is formed. The fuel supply nozzle  29  also has a cylindrical valve sleeve  31  which allows the fuel supply nozzle  29  to fit therein in a slidable manner in a state that the fuel supply nozzle  29  can be slid relatively between a lower side closing position at which the respective valve holes  30  are closed and an upper side opening position at which the respective valve holes  30  are opened in the axial direction. The fuel supply nozzle  29  also has a cylindrical slider  32  which allows the valve sleeve  31  to fit therein in a slidable manner in a state that the valve sleeve  31  can be slid relatively in the axial direction. The fuel supply nozzle  29  also has a spring  34  which is provided in a shrinkable manner between a retainer  33  which is fixed to an upper portion of the fuel supply nozzle  29  and the slider  32 .  
         [0024]     An annular restricting stepped portion  35  which faces upwardly is formed on an outer periphery of the fuel supply nozzle  29  close to the first end of the fuel supply nozzle  29 . By bringing the valve sleeve  31  into contact with the restricting stepped portion  35 , a movable limit of the valve sleeve  31  in the downward direction from the lower-side closing position is restricted. Further, on an outer periphery of the first end portion of the fuel supply nozzle  29 , an annular sealing member  36  is mounted, which is resiliently brought into contact with an inner periphery of the valve sleeve  31  arranged at the lower side closing position. On an outer periphery of an intermediate portion of the fuel supply nozzle  29 , a pair of annular sealing members  37  and  38  is mounted in a spaced apart manner from each other. The annular sealing members  37  and  38  are resiliently brought into contact with an inner periphery of the valve sleeve  31  irrespective of an axially relative position thereof with respect to the fuel supply nozzle  29 . Further, a first end of the valve sleeve  31  can be brought into contact with the annular projection  15   c  of the fuel filling port  16  when the valve sleeve  31  is inserted into the inside of the fuel filling port  16 . An annular sealing member  39 , which is resiliently brought into contact with the inner periphery of the fuel filling port  16 , is mounted on an outer periphery of the first end portion of the valve sleeve  31 .  
         [0025]     A first annular recessed portion  41  is formed in an outer periphery of the intermediate portion of the fuel supply nozzle  29 . The first annular recessed portion  41  stores approximately half of a coil spring  40 , which is formed into an annular shape so as to be brought into contact with a second end of the valve sleeve  31  arranged at the lower side closing position. Further, the valve sleeve  31  has a thickness corresponding to a projection quantity of the coil spring  40  in the radially outward direction from the fuel supply nozzle  29  in a state that approximately half of the coil spring  40  is stored in the first annular recessed portion  41 . On a second end of the slider  32  which allows the valve sleeve  31  to fit therein in an axially and relatively slidable manner, an inward flange portion  32   a  is integrally formed in a state that the inward flange portion  32   a  projects in the radially inward direction. The inward flange portion  32   a  can be brought into contact with a portion of the coil spring  40  projected from the first annular recessed portion  41  from above.  
         [0026]     Further, on an inner surface of the slider  32 , which is arranged closed to the second end of the slider  32 , a second annular recessed portion  42  is formed. The second annular recessed portion  42  stores an approximately half of the fuel supply nozzle  29  when the coil spring  40 , which is brought into contact with the second end of the valve sleeve  31  in moving the valve sleeve  31  to the upper side opening position with respect to the fuel supply nozzle  29 , is removed from the first annular recessed portion  41  toward an outer periphery of the fuel supply nozzle  29 .  
         [0027]     The retainer  33  is integrally formed of a disc portion  33   a , having a through hole  43  which allows the fuel supply nozzle  29  to penetrate therethrough in a center portion thereof, and a cylindrical portion  33   b , which is contiguously connected with an outer periphery of the disc portion  33   a  at a right angle and extends toward the tank body  12  side. By mounting a pair of retainer rings  44  and  45 , which sandwich the disc portion  33   a  from both sides at a periphery of the through hole  43  on an outer periphery of the fuel supply nozzle  29 , the retainer  33  is fixed to the fuel supply nozzle  29 . The spring  34  is formed in a coil shape and surrounds the fuel supply nozzle  29  and the slider  32 . The spring  34  is arranged in a shrinkable manner between an annular receiving stepped portion  32   b , which is formed on an outer periphery of the slider  32  while facing the retainer  33  side, and the disc portion  33   a  of the retainer  33 .  
         [0028]     On a second end portion of the fuel supply nozzle  29 , a connection member  46  to which a fuel hose not shown in the drawing is connected, is hermetically fitted. On the connection member  46 , a flange portion  46   a , which is provided for applying a force to push the fuel supply nozzle  29  into the fuel filling port  16 , is integrally formed in a state that the flange portion  46   a  projects outwardly in the radial direction. A retainer ring  47 , which is capable of coming into contact with a first end of the connection member  46 , is mounted on an outer periphery of the fuel supply nozzle  29  for transmitting an external force applied to the flange portion  46   a  to the fuel supply nozzle  29  from the connection member  46 .  
         [0029]     Here, when the manipulation to push the fuel supply device  28 , which includes the fuel supply nozzle  29 , is not performed, although the fuel supply device  28  is engaged with the lid  25  at the closed position, the lid  25  is held in the closed position. Lid locking mechanisms  50 , which allow an operation of the lid  25  to move to the open position side in response to the pushing manipulation of the fuel supply device  28 , are provided to the fuel tank  11 . The lid locking mechanisms  50  are mounted on three portions of the fuel tank  11  and are spaced apart equidistantly in the circumferential direction of the fuel filling port  16  at the periphery of the fuel filling port  16 .  
         [0030]     To explain also in conjunction with  FIG. 2  and  FIG. 3 , each lid locking mechanism  50  includes a rotary shaft  51 , which is rotatably supported on the mouthpiece  15  of the fuel tank  11 . Each lid locking mechanism also includes a cam  52 , which is fixed to a first end of the rotary shaft  51  in a state that the cam  52  is rotated while being in contact with the fuel supply device  28  in response to the pushing manipulation of the fuel supply device  28 . Each lid locking mechanism also includes an engaging member  53 , which is fixed to a second end of the rotary shaft  51  in a state that the engaging member  53  is rotated toward a side which releases the engagement of the engaging member  53  with the lid  25  in response to the rotation of the cam  52  corresponding to the pushing manipulation of the fuel supply device  28 .  
         [0031]     Here, at three center portions between three guide shafts  19 , notched portions  54 , which are opened at a second end side of the cylindrical portion  15   a , are formed in the cylindrical portion  15   a . Planar support surfaces  55 , which face the outside, are formed of closed ends of the notched portions  54 . Portions which are formed by raising portions of the flange portion  15   b  become coplanar with the closed ends. Further, at positions corresponding to a contiguously connecting portion between the cylindrical portion  15   a  and the flange portion  15   b , small-diameter holes  56 , which have a first end thereof opened in the inside of the tank body  12 , are formed. Additionally, at positions corresponding to a contiguously connecting portion between the cylindrical portion  15   a  and the flange portion  15   b , large diameter holes  57  are formed, which have first ends thereof coaxially communicated with second ends of the small-diameter holes  56 , and have second ends thereof opened in the support surface  55 . Annular stepped portions  58 , which face the outside, are formed between the second ends of the small-diameter holes  56  and the first ends of the large-diameter holes  57  having a larger diameter than the small diameter holes  56 .  
         [0032]     In the small-diameter hole  56 , the rotary shaft  51  having a flange portion  51   a , which is brought into contact with a first end of the mouthpiece  15 , is rotatably inserted. The cam  52  is fixed to a projecting end of the rotary shaft  51 , which projects from the support surface  55  by a pin  59 , for example. Further, between the rotary shaft  51  and the cam  52  and the mouthpiece  15 , a bearing member  60  which makes the rotation of the rotary shaft  51  smooth is interposed. The bearing member  60  includes a cylindrical portion  60   a , which is inserted in a gap defined between the rotary shaft  51  and the large diameter hole  57 , and a flange portion  60   b , which is integrally and contiguously formed with the cylindrical portion  60   a  in a state that the flange portion  60   b  is interposed between the cam  52  and the support surface  55 . An annular sealing member  61  which coaxially surrounds the rotary shaft  51  is sandwiched between a first end of the cylindrical portion  60   a  and the stepped portion  58 .  
         [0033]     The cam  52  is integrally formed of a contact projection  52   a , which has a distal end thereof projected into the inside of the fuel filling port  16 , and a restricting projection  52   b , which is arranged about an axis of the rotary shaft  51  at a position offset from the contact projection  52   a . The cam  52  is rotatable between a projection position indicated by a solid line in  FIG. 2 , at which the restricting projection  52   b  is brought into contact with a first end side of the notched portion  54  along the circumferential direction of the mouthpiece  15  so as to project a distal end of the contact projection  52   a  into the inside of the fuel filling port  16 , and a retracting position indicated by a chained line shown in  FIG. 2 , at which the contact projection  52   a  is brought into contact with a second end side of the notched portion  54  along the circumferential direction of the mouthpiece  15  so as to retract the contact projection  52   a  to the outside of the fuel filling port  16 .  
         [0034]     Further, the engaging member  53  integrally includes an engaging projection  53   a  which is brought into contact with and also is engaged with an inner surface of an outer peripheral portion of the lid  25 , which assumes a position at which the fuel filling port  16  is closed as shown in  FIG. 1 . The engaging member  53  is fixed to the second end of the rotary shaft  51  using a pin  62 , for example. The engaging member  53  is fixed to the rotary shaft  51  such that when the cam  52  is at a projecting position, it assumes a rotary position at which the engaging projection  53   a  is brought into contact with and also is engaged with the lid  25 . When the cam  52  is at a retracting position, the engaging portion assumes a rotary position at which the engagement of the engaging projection  53   a  with the lid  25  is released.  
         [0035]     Further, between the rotary shaft  51  and the fuel tank  11 , a spring  63  is provided which allows a distal end of the contact projection  52   a  which forms a portion of the cam  52 , to project into the inside of the fuel filling port  16  and, at the same time, which resiliently biases the rotary shaft  51  to a side at which the engaging projection  53   a , which forms a portion of the engaging member  53 , is engaged with the lid  25 . The spring  63  is a torsion spring which surrounds the rotary shaft  51  between the flange portion  51   a  of the rotary shaft  51  and the engaging member  53 . The spring  63  has a first end thereof engaged and connected with the engaging member  53 , and a second end of the spring  63  is engaged and connected with a pin  64  which is mounted on the support ring  14 .  
         [0036]     Here, in a state that the cam  52  allows the distal end of the contact projection  52   a  to project into the inside of the fuel filling port  16  and, at the same time, the engaging member  53  is at a position where engaging member  53  allows the engaging projection  53   a  to be engaged with the lid  25  at a closed position, when the fuel supply device  28  is pushed into the inside of the fuel filling port  16 , the first end of the valve sleeve  31  in the fuel supply device  28  is brought into contact with an inclined surface  65  formed on an upper surface of the distal end of the contact projection  52   a . The inclined surface  65  is inclined such that the inclined surface  65  assumes an upper position along with the progress of the inclined surface  65  in the clockwise direction shown in  FIG. 2  about an axis of the rotary shaft  51 . Corresponding to the application of a pushing force to the inclined surface  65  of the contact projection  52   a  from the first end of the valve sleeve  31 , a force which rotates the cam  52  toward the retracting position is applied to the cam  52  and the rotary shaft  51  and hence, due to the rotation of the rotary shaft  51 , the engaging member  53  is also rotated to a side at which the engagement of the engaging projection  53   a  with the lid  25  is released.  
         [0037]     Further, on a lower surface of a distal end portion of the contact projection  52   a , a curved surface  66  is formed for preventing, in removing the fuel supply device  28  from the fuel filling port  16 , a portion of the fuel supply device  28  from being engaged with the contact projection  52   a  even when the portion of the fuel supply device  28  is brought into contact with the contact projection  52   a  from below. On a lower surface of a distal end portion of the engaging projection  53   a  in the engaging member  53 , a curved surface  67  is formed for preventing, in removing the fuel supply device  28  from the fuel filling port  16 , a portion of the fuel supply device  28  from being engaged with the engaging projection  53   a  even when the portion of the fuel supply device  28  is brought into contact with the engaging projection  53   a  from below.  
         [0038]     In such lid locking mechanisms  50 , when the fuel supply device  28  is inserted into the fuel filling port  16  of the fuel tank  11 , the first end of the valve sleeve  31  in the fuel supply device  28  is brought into contact with the inclined surfaces  65  formed on the distal ends of the contact projections  52   a  in the respective cams  52 . Accordingly, as shown in  FIG. 4  and  FIG. 5 , when the fuel supply device  28  is pushed downwardly until a first end of the slider  32  is brought into contact with the outer end of the mouthpiece  15 , the cams  52  are rotated to the retracting position and hence, the engaging member  53  is rotated to the position at which the engagement of the engaging member  53  with the lid  25  is released. When a pushing force downwardly in the axial direction is applied to the fuel supply nozzle  29  of the fuel supply device  28 , as shown in  FIG. 6 , it is possible to push down the valve sleeve  31  until the valve sleeve  31  is brought into contact with the annular projection  15   c  in the inside of the fuel filling port  16  along with the shrinkage of the spring  34  while holding the slider  32  in a contact state with the mouthpiece  15 . In this case, corresponding to the relative movement of the valve sleeve  31  in the axial direction with respect to the slider  32 , the coil spring  40 , which has approximately half thereof housed in the first annular recessed portion  41  is moved to a position at which approximately half of the coil spring  40  can be housed in the second annular recessed portion  42 . By further pushing down the fuel supply nozzle  29 , the coil spring  40  is removed from the first annular recessed portion  41  and assumes a state in which approximately half of the coil spring  40  is housed in the second annular recessed portion  42  while being in slidable contact with an outer periphery of the fuel supply nozzle  29 .  
         [0039]     When the fuel supply nozzle  29  is further pushed down, as shown in  FIG. 7 , the first end of the fuel supply nozzles  29  projects into the inside of the fuel tank  11 , and the valve sleeve  31  is moved relatively to the upper open position with respect to the fuel supply nozzle  29  and hence, the valve holes  30  at the first end portion of the fuel supply nozzle  29  are opened, whereby fuel flows into the inside of the fuel tank  11  through the respective valve holes  30  of the fuel supply nozzles  29 .  
         [0040]     The lid locking mechanisms  50 , which allows the operation of the lids  25  to the open position side corresponding to the pushing manipulation of the fuel supply device  28  while holding the lids  25  at the closed position by being engaged with the lid  25  at the closed position when the manipulation to push the fuel supply device  28  is not performed, are provided to the fuel tank  11  at the peripheries of the fuel filling ports  16 . When the manipulation to push the fuel supply device  28  into the fuel filling port  16  is performed, the closed position locking state of the lid  25  is released by the lid locking mechanisms  50  and the fuel filling ports  16  can be opened by pushing down the lid  25 . On the other hand, even when a pushing force is applied to the lid  25  using an object other than the fuel supply device  28 , the closed position of the lid  25  is held by the lid locking mechanisms  50  and hence, there is no possibility that the lid  25  is operated to open the fuel filling ports  16 . That is, opening of the fuel filling ports  16  by objects other than the fuel supply device  28  can be prevented.  
         [0041]     Further, since the lid locking mechanisms  50  are provided to the fuel tank  11  at three portions which are arranged equidistantly in the circumferential direction of the fuel filling port  16  and hence, three portions of the fuel supply device  28  which are equidistantly arranged in the circumferential direction are brought into contact with the lid locking mechanisms  50 . Thus, it is possible to stably support the fuel supply device  28  at the time of performing the manipulation to push the fuel supply device  28  into the fuel filling port  16 .  
         [0042]     Although the embodiments of the present invention have been explained heretofore, the present invention is not limited to the above-mentioned embodiments and various modifications in design can be performed without departing from the gist of the present invention described in claims.