Abstract:
A gas fuel filling lid device for a vehicle using a high-pressure gas as the fuel has a fuel filling opening for filling the vehicle with the high-pressure gas fuel, a lid openably attached to the vehicle and covering the fuel filling opening, and a cap for the fuel filling opening. The filling opening cap is fitted to the inner surface of the lid and is connected to and disconnected from the fuel filling opening in operative association with opening and closing of the lid. The structure prevents the user from forgetting to close the filling opening cap and facilitates the connection and disconnection of the filling opening cap.

Description:
This is a 371 national phase application of PCT/JP2007/051654 filed 25 Jan. 2007, claiming priority to Japanese Patent Application No. 2006-019703 filed 27 Jan. 2006, the contents of which are incorporated herein by reference. 
     FIELD OF THE INVENTION 
     The present invention relates to a gas fuel filler lid device for a vehicle using high pressure gas as a fuel, such as a fuel-cell vehicle. 
     BACKGROUND OF THE INVENTION 
     In recent years, much research has been directed at developing fuel-cell vehicles equipped with fuel cells for practical use. One example is a vehicle in which a fuel in a gaseous state (“fuel gas”) and oxidant gas are supplied into a fuel cell where these gases (reactant gases) are electrochemically reacted to obtain a driving output. Because air can be used as the oxidant gas in this vehicle, it is not necessary to store an oxidant gas inside the vehicle, but only the fuel gas composed of hydrogen. As a method for filling the fuel gas into the vehicle, a similar method as for a gasoline vehicle may be used. Specifically, the fuel gas may be supplied into a fuel gas container provided inside the vehicle by inserting a fuel gas filler nozzle provided at an external fuel gas filling station into a fuel gas filler opening disposed on the vehicle. 
     For example, Japanese Patent Publication JP 2003-291667 A describes use of a conventional technique for fueling a fuel-cell vehicle with a fuel gas. As shown in  FIG. 6 , in a conventional technique for fueling a fuel-cell vehicle  11  with a fuel gas, a fuel gas filler nozzle  13  of an external fuel gas supplying device  12  (that is, provided separately from the fuel-cell vehicle  11 ) is inserted into a fuel gas filler opening  14  of the fuel-cell vehicle  11 . Then, fuel gas (hydrogen gas) is transferred into a fuel gas tank  15 , which is a tank for storing a fuel gas (hydrogen gas), via the fuel gas filler opening  14  from the fuel gas filler nozzle  13 . Further, a grounding line portion  16  of the fuel gas supplying device  12  is connected to the fuel-cell vehicle  11 . The grounding line portion  16  is grounded at the fuel gas supplying device  12  to discharge static electricity from the fuel-cell vehicle  11 . 
     As shown in  FIGS. 7 and 8 , a recess  21  which is concave from the outer surface of a vehicle body  20  is provided on a rear side portion of the body  20  of the fuel-cell vehicle  11 . The fuel gas filler opening  14  is disposed obliquely upward on the bottom of the recess  21 . A valve mechanism or a filter is mounted inside the fuel gas filler opening  14  in order to prevent back-flow of the fuel gas. Thus, a fuel gas filler opening cap  23  is attached to the fuel gas filler opening  14  to prevent an operational failure of the valve mechanism or filter clogging due to foreign materials having entered into the fuel gas filler opening  14 . The fuel gas filler opening cap  23  is manually attached and detached by a person (for example, a driver or a shop attendant) fueling the vehicle with fuel gas. 
     In a concaved portion  21 , there is provided a lid  26  which is swingably attached to the vehicle body  20  via a hinge mechanism  25  such that the lid  26  swings to change between a closed state for closing the recess  21  and an open state for opening the recess  21 . When the lid  26  is in a closed state, the fuel gas filler opening  14  and the fuel gas filler opening cap  23  are closed by the lid  26  to achieve a state wherein the opening is inaccessible from outside, while when the lid  26  is in an opened state, the fuel gas filler opening  14  is exposed and accessible from outside. 
     In order to fuel a conventional fuel-cell vehicle  11  having the above structure with a fuel gas from the fuel gas supplying device  12  by the method as shown in  FIG. 6 , the person fueling the vehicle should perform procedures including, at first, releasing the lid  26  to expose the fuel gas filler opening  14 , manually removing the fuel gas filler opening cap  23  which is covered over the fuel gas filler opening  14 , and connecting the fuel gas filler nozzle  13 . After completing filling of the fuel gas, the person should manually attach the fuel gas filler opening cap  23  and finally, close the lid  26 . 
     However, because the lid  26  can be closed (set into a closed state) without attaching the fuel gas filler opening cap  23 , and because, as in a gasoline vehicle, the fuel gas filler opening  14  is disposed obliquely upward, there is a disadvantage that foreign material may enter the tank if the fuel gas filler opening cap  23  is accidentally left unclosed, even if a drop-prevention string  24  is attached to the fuel gas filler opening  14  as shown in  FIGS. 7 and 8  in order to prevent the cap from being dropped or misplaced when the cap is manually removed. Further, another disadvantage is that, because the fuel gas filler opening cap  23  is tightly attached to the fuel gas filler opening  14  in the structure, it may be difficult to manually attach or remove the cap, so an attachment failure may occur. Therefore, an object of the present invention is to prevent the fuel gas filler opening cap  23  from being accidentally left unclosed and to facilitate attachment and removal of the fuel gas filler opening cap  23 . 
     SUMMARY OF THE INVENTION 
     According to one aspect of the present invention, there is provided a gas fuel filler lid device for a vehicle using high pressure gas as a fuel, comprising a fuel filler opening that is used to fill the high pressure gas to the vehicle; a lid that is mounted on the vehicle to cover the fuel filler opening such that the lid can be freely opened and closed; and a fuel filler opening cap that covers over an outer surface of the fuel filler opening to prevent a foreign material from entering, wherein the fuel filler opening cap is mounted on an internal surface of the lid and includes, on an internal surface, a projecting portion that contacts and seals with the outer surface of the fuel filler opening, and the fuel filler opening cap is attached to or detached from the outer surface of the fuel filler opening in conjunction with opening and closing movement of the lid. According to another aspect of the invention, the fuel filler opening cap may have, at an opening side, an internal diameter which is larger than an internal diameter at a lid side. 
     Thus, the present invention can prevent the fuel gas filler opening cap from being accidentally left unclosed so as to prevent foreign materials from entering into the fuel gas filler opening, and at the same time, the present invention can facilitate attachment and detachment of the fuel gas filler opening cap. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an embodiment of a gas fuel filler lid device according to the present invention. 
         FIG. 2  is a plan sectional view of an embodiment of a gas fuel filler lid device according to the present invention. 
         FIG. 3  is a sectional view showing a fuel gas filler opening cap being attached to the fuel gas filler opening of an embodiment of a gas fuel filler lid device according to the present invention. 
         FIG. 4  is a perspective view showing a method for attaching a fuel gas filler opening cap of a gas fuel filler lid device according to an embodiment of the present invention. 
         FIG. 5  is a diagram explaining a method for filling fuel gas using a gas fuel filler lid device according to an embodiment of the present invention. 
         FIG. 6  is a diagram explaining a method for filling fuel gas according to a conventional art. 
         FIG. 7  is a perspective view showing a fuel gas filler opening and a lid according to a conventional art. 
         FIG. 8  is a front view showing a fuel gas filler opening and a lid according to a conventional art. 
     
    
    
     DETAILED DESCRIPTION 
     A preferred embodiment of the present invention is described below with reference to the accompanying drawings. Similar reference numbers are used to denote components similar to components used in the conventional art as described above and their explanation is not repeated.  FIG. 1  shows a gas fuel filler lid device for a vehicle according to this embodiment of the present invention. In  FIG. 1 , a fuel gas filler opening  14  is fixed to a bottom of a recess  21  which is provided on a side surface of a vehicle body  20  and extends towards inside the vehicle body  20  in such a manner that the fuel gas filler opening  14  is secured to the vehicle body  20  by nuts  28  clamping both sides of a reinforcing plate  27  inbetween. The tip of the fuel gas filler opening  14  which engages with a fuel gas filler nozzle  13  is placed within the depth of the recess  21  extending towards inside the vehicle. A lid  26  is swingably attached to the vehicle body  20  via a hinge mechanism  25  mounted on the vehicle body  20  such that, in a closed state, the lid  26  covers the recess  21  and the fuel gas filler opening  14 , while when the lid  26  is in an opened state the recess  21  and the fuel gas filler opening  14  are exposed. Thus, when the lid  26  is in the opened state, the tip potion of the fuel gas filler opening  14  which engages with the fuel gas filler nozzle  13  and the recess  21  extending towards inside the vehicle are exposed to allow the tip of the fuel gas filler nozzle  13  to enter within the recess  21  such that the bore of the fuel gas filler nozzle  13  engages with the fuel gas filler opening  14  to enable filling with fuel. When the fueling (filling with fuel) is completed, the lid  26  can be closed to cover the recess  21  and the fuel gas filler opening  14 . In that state, the surface of the lid  26  is disposed substantially in the same plane with the surface of the vehicle body  20 . 
     A cap stopper  30  which is substantially U-shaped is fixed on a recess side (internal side) of the lid  26 . As shown in  FIG. 4 , the fuel gas filler opening cap  23  is fixed on the concave side of the lid  26  by fitting a fuel gas filler opening cap supporting groove  23   a  formed around the fuel gas filler opening cap  23  into the cap stopper  30 . The fuel gas filler opening cap  23  is made of an elastic material such as rubber and plastic so that the fuel gas filler opening cap  23  can, when it is tightly attached to the outer cylinder surface of the fuel gas filler opening  14 , prevent foreign materials from entering into the gas filler opening  14 . It should be noted that the form of the cap stopper  30  is not limited to a U-shape, but may be any form as long as the cap stopper  30  can releasably hold the fuel gas filler opening cap  23  by engaging with the fuel gas filler opening cap supporting groove  23   a  formed on the side surface of the fuel gas filler opening cap  23 . 
     As shown in  FIG. 2 , when the lid  26  is swung about the hinge mechanism  25  to open or close the recess  21 , the fuel gas filler opening cap  23  can be attached or detached from the fuel gas filler opening  14  in conjunction with such opening and closing movement of the lid  26 . As shown in  FIG. 3 , the fuel gas filler opening  14  includes a stepped-down portion  14   b  on the outer surface at the tip portion for engaging with the fuel gas filler nozzle  13 , and sealing portions  14   a , which sandwich the stepped-down portion  14   b , for sealing gas between the fuel gas filler nozzle  13  and the fuel gas filler opening  14 . The fuel gas filler opening cap  23  internally includes a fuel gas filler opening cap sealing portion  31  which is annular shaped and projecting towards inside. The fuel gas filler opening cap sealing portion  31  contacts and tightly seals with the fuel gas filler opening  14  at the sealing portion  14   a  of fuel gas filler opening  14 . Because foreign materials can be prevented from entering without tightly attaching other portions of the internal surface of the fuel gas filler opening cap  23  than the fuel gas filler opening cap sealing portion  31  to the outer surface of the fuel gas filler opening  14 , the fuel gas filler opening cap  23  is formed to have a slight gap as shown in  FIG. 3 . Further, the fuel gas filler opening cap  23  has a shape such that the internal diameter at the opening side is larger than the internal diameter at the lid side. Thus, because in opening or closing the lid  26 , the fuel gas filler opening cap  23  is not impeded such as by being caught at the edge of the fuel gas filler opening  14 , the fuel gas filler opening cap  23  can be smoothly attached or detached in conjunction with opening or closing movement of the lid  26 . Still further, because the fuel gas filler opening cap sealing portion  31  contacts in a line with the sealing portion  14   a  which is disposed at the outer circumference of the fuel gas filler opening  14 , frictional resistance in attaching and detaching the fuel gas filler opening cap  23  is low enabling smoother attachment and detachment. 
     In the above described embodiment of the present invention, the fuel gas filler opening cap  23  is fixed by being inserted into the cap stopper  30  mounted inside of the lid  26  so that it is possible to exchange the fuel gas filler opening cap  23  and to facilitate assembly. However, the fuel gas filler opening cap  23  may be directly fixed to the concave side of the lid  26  by adhesive agent or the like. Further, the lid  26  may be swingably attached to the vehicle by means other than the hinge mechanism  25 , such as by a flexible material including rubber and resin. 
     According to the present invention, because the fuel gas filler opening cap  23  can be attached to or detached from the fuel gas filler opening  14  in conjunction with opening and closing of the lid  26 , advantages are provided in that it is possible to prevent the fuel gas filler opening cap  23  from being accidentally left unclosed and to enable smooth attachment and detachment of the fuel gas filler opening cap  23  in conjunction with the opening and closing of the lid  26 . 
     Moreover, the fuel gas filler nozzle  13  can be inserted into the fuel gas filler opening  14  in a horizontal direction by mounting the fuel gas filler opening  14  horizontally to the fuel-cell vehicle  11  and by using a balancing unit  46  shown in  FIG. 5  in which a supporting rod  42  is connected to one end of a column  40  by a hinge  44 , a weight  41  is connected to one end of the supporting rod  42 , and a wire  43  for lifting the fuel gas filler nozzle  13  is attached to the other end of the supporting rod  42  at the side where the fuel gas supplying device  12  is disposed. By providing a structure in which the fuel gas filler opening  14  is disposed in a horizontal direction as described above, the lid  26  is opened and closed in a horizontal direction, and the fuel gas filler opening cap  23  which is attached or detached in conjunction with the opening and closing of the lid  26  is provided, it is possible to achieve the advantages of preventing foreign materials from entering into the fuel gas filler opening  14  and facilitating filling of the fuel-cell vehicle  11  with fuel gas. 
     In the above embodiment of the present invention, the present invention is explained using examples of its application to a fuel-cell vehicle  11 . However, it should be noted that the present invention is applicable to any vehicle using a high-pressure gas fuel, such as, for example, a natural gas vehicle.