Abstract:
The present invention enables a canister in a fuel tank with the canister to be separately subjected to a product inspection and enables the canister to be replaced. 
     The fuel tank according to the present invention includes: a tank body ( 10   m ) configured by joining a plurality of shells ( 12 ) and ( 14 ) to each other; and a canister ( 20 ) configured to enable absorption of fuel vapor generated in the tank body ( 10   m ), wherein, in one ( 12 ) of the shells that constitute the tank body ( 10   m ), and engaging portion ( 120 ) formed to be integral with the shell ( 12 ) is provided, and the canister ( 20 ) is configured to be mounted to the tank body ( 10   m ) by engaging an engaged portion ( 20 r) of the canister ( 20 ) with the engaging portion ( 120 ).

Description:
TECHNICAL FIELD  
       [0001]    The present invention relates to a fuel tank which includes a task body configured by joining a plurality of shells to each other, and a canister configured to enable adsorption of fuel vapor generated is the tank body. 
       BACKGROUND ART 
       [0002]    A technique related to the tank described above is disclosed in PTL 1. 
         [0003]    The tank body of the furl tank is constituted by an upper shell and a lower shell, which are made of an injection-molded resin. The container body of the canister is formed to be integrated with the inner wall surface of the upper shell whets the upper shell is injection-molded. The container body of the canister is filled with an absorbent such as activated carbon, and an opening of the container body is closed by a cover material. Next, a flange portion of the upper shell and a flange portion of the lower shell are joined to each other, thereby completing the tank body. 
       CITATION LIST  
     Patent Literature 
       [0004]    [PTL 1] JP-A-2008-168767 
       SUMMARY OF THE INVENTION  
     Technical Problem 
       [0005]    In the fuel tank described above, when the upper shell included in the tank body is injection-molded, the container body of the canister is formed to be integrated with the inner wall surface of the upper shell. Therefore, even in case where only the canister is to be detached and attached afterward, detaching and attaching of the canister is not possible. Furthermore, it is difficult for the canister to be separately subjected to a product inspection.  
         [0006]    The present invention has been made to solve the above problems, and a technical object of the present invention is to enable a canister in a fuel tank with the canister to be separately subjected to a product inspection and enable the canister to be detachable and attachable. 
       Solution to Problem 
       [0007]    The above-described problems are solved by the invention of each of claims. 
         [0008]    According to the invention of claim  1 , a fuel tank included: a tank body configured by joining a plurality of shells to each other, and a canister configured to enable absorption of fuel vapor generated in the tank body, wherein, in one of the shells that constitute the tank body, an engaging portion formed to be integrated with the shell is provided, and the canister is configured to be mounted to the tank body by engaging an engaged portion of the canister with the engaging portion. 
         [0009]    According to the present invention, by engaging the engaged portion of the canister with the engaging portion of the shell, the canister is mounted to the shell. In addition, by joining the shell to the other shell, the tank body of the fuel tank is formed. 
         [0010]    In this manner, since the canister is configured to be mounted to the shell (the tank body) by the action of engagement between the engaged portion and the engaging portion, the canister is able to be separately subjected to a product inspection before being mounted to the shell. In addition, the canister is also detachable by disengaging the engaged portion of the canister from the engaging portion of the shell. 
         [0011]    According to the invention of claim  2 , a plurality of the engaging portions are formed on an inner wall surface of the shell, and the canister is configured to be mounted to an inside of the tank body. 
         [0012]    In this manner, since the canister is mounted to the inside of the tank body, even in a case where the fuel vapor permeates the canister, the fuel vapor does not leak out to the atmosphere. Furthermore, compared to a case where the canister is mounted to the outside of the tank body, the shape of the fuel tank is not complex. 
         [0013]    According to the invention of claim  3 , a vapor passage which guides the fuel vapor generated in the tank body to the canister in the tank body, and an inflow regulating valve which is provided in the vapor passage and prevents liquid fuel in the tank body from flowing into the canister are integrated with the canister. 
         [0014]    In this manner, since the vapor and the inflow regulating valve are integrated with the canister and are mounted to the inside of the tank body, the fuel vapor that leaks out from the vapor passage and the like does not leak out into the atmosphere. 
         [0015]    According to the invention of claim  4 , when the engaged portion of the canister is engaged with the engaging portion formed on the inner wall surface of the shell, an atmosphere port and a purge port of the canister are configured to be respectively inserted into an atmosphere port connection portion and a purge port connection portion which are formed in the shell so as to be connected. 
         [0016]    Therefore, an operation of connecting the atmosphere port connection portion and the purge port connection portion of the shell to the atmosphere port and the purge port of the canister is facilitated. 
         [0017]    According to the invention of claim  5 , the plurality of shells include an upper shell, that constitutes an upper portion of the tank body and a lower shell that forms a lower portion of the tank body, and the canister is mounted to the inside of the upper shell at a position higher than an upper limit portion of a liquid level of the fuel. 
         [0018]    Accordingly, a space where the fuel vapor is accumulated in the tank body is reduced by the volume of the canister, and the amount of the fuel vapor generated is reduced. In addition, since the canister is housed in the tank body, the amount of fuel stored is not reduced. 
       ADVANTAGEOUS EFFECTS OF INVENTION 
       [0019]    According to the present invention, the canister in the fuel tank with the canister is able to be separately subjected to a product inspection, and the canister is detachable and attachable. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0020]      FIG. 1  is a schematic diagram illustrating the configuration of a canister in a fuel tank according to a first embodiment of the present invention. 
           [0021]      FIG. 2  is a schematic longitudinal cross-sectional view of the fuel tank. 
           [0022]      FIG. 3  is a schematic plan view of the fuel tank. 
           [0023]      FIG. 4A  is a longitudinal cross-sectional view illustrating a canister mounting structure in a fuel tank,  FIG. 4B  is a schematic diagram illustrating a claw portion and a claw receiving portion, and  FIG. 4C  is a schematic diagram illustrating an action of a fill-up regulating valve. 
           [0024]      FIG. 5  is a schematic diagram illustrating the configuration of a canister in a fuel tank according to a modification example. 
           [0025]      FIG. 6  is a plan view illustrating the fuel tank according to the modification example. 
           [0026]      FIG. 7  is a longitudinal cross-sectional view illustrating the fuel tank according to the modification example. 
           [0027]      FIG. 8  is a side view illustrating the fuel tank according to the modification example. 
       
    
    
     DESCRIPTION OF EMBODIMENTS  
     First Embodiment  
     &lt;Summary of Fuel Tank  10 &gt; 
       [0028]    Hereinafter, a fuel tank according to a first embodiment of the present invention will be described with respect to  FIGS. 1 to 8 . The fuel tank according to this embodiment is a fuel tank with a canister to be used in a vehicle. 
         [0029]    The fuel tank  10  includes a tank body  10   m  constituted by an upper shell  12  and a lower shell  14  as illustrated in  FIG. 2  and the like. The upper shell  12  and the lower shell  14  are resin injection-molded products, and the surfaces thereof are covered with a barrier layer B having fuel permeation resistance. Here, as a resin that is a body material of the upper shell  12  and the lower shell  14 , for example, high-density polyethylene (HDPE) is used, and as a material of the barrier layer B, and ethylene vinyl alcohol copolymer (EVOH) is used. 
         [0030]    The upper shell  12  is formed by an upper plate portion  12   u  and a side plate portion  12   s  in a square container shape in which the lower side thereof is opened, and a flange portion  12   f  is formed at the peripheral edge of a lower side opening  12   h.  In addition, at predetermined positions of the rear surface (lower surface) of the upper plate portion  12   u  of the upper shell  12 , as illustrated in  FIG. 4A , a plurality of the claw portions  120  are formed to protrude downward in order to mount the canister  20  to the inner side upper portion of the upper shell  12 . The claw portion  120  is formed to be integrated with the upper shell  12 , and as illustrated in  FIG. 4B , is constituted by a flat portion  122  and a wedge-shaped hook portion  124  formed at the tip of the flat plate portion  122 . The flat plate portion  122  of the claw portion  120  is configured to be elastically deformable in the thickness direction, and a stepped portion  125  is formed between the flat plate portion  122  and the hook portion  124 . As the plurality of claw portions  120  of the upper shell  12  are engaged with a plurality of claw receiving portions  20   r  of the canister  20  as described later, the canister  20  is mounted to the upper shell  12 . 
         [0031]    In addition, in the upper plate portion  12   u  of the upper shell  12 , a purge port connection portion  130  to which a purge port  20   p  of the canister  20  is connected from the inside and an atmosphere port connecting portion  140  to which an atmosphere port  20   e  (see  FIG. 1 ) of the canister  20  is similarly connected from the inside are formed. as illustrated in  FIG. 4 , the purge port connection portion  130  is constituted by a large-diameter port receiving portion  132  into which the purge port  20   p  of the canister  20  is inserted from below to be connected, and a small-diameter connector portion  134  to which a connector  11   c  of a purge pipe  11   p  that communicates with an intake pipe W (see  FIG. 1 ) of an internal combustion engine E is connected. The atmosphere port connection portion  140  has the same configuration as that of the purge port connection portion  130 , and is constituted by a port receiving portion (not shown) into which the atmosphere port  20   e  of the canister  20  is inserted from below to be connected and a connector portion (not shown) to which an atmosphere opening pipe  11   e  (see  FIG. 1 ) is connected. 
         [0032]    The purge port connection portion  130  and the atmosphere port connection portion  140  of the upper shell  12  are formed at positions where the purge port  20   p  and the atmosphere port  20   e  of the canister  20  are inserted to be connected when the claw portions  120  of the upper shell  12  are engaged with the claw receiving portions  20   r  of the canister  20 . 
         [0033]    As illustrated in  FIG. 2 , the lower shell  14  is formed by a bottom plate portion  14   d  and a side plate portion  14   s  in a square container shape in which the upper side thereof is opened, and a flange portion  14   f  is formed at the peripheral edge of an upper side opening  14   h . The flange portion  14   f  of the lower shell  14  and the flange portion  12   f  of the upper shell  12  are joined to each other, thereby forming the tank body  10   m.    
       &lt;Canister  20 &gt; 
       [0034]    As illustrated in  FIG. 1 , the canister  20  is configured to enable absorption of fuel vapor which is generated in the tank body  10   m  and enable the adsorbed fuel vapor to be supplied to the intake pipe W of the engine E. As illustrated in the schematic diagram of  FIG. 1 , the canister  20  includes a sealed type housing  21 , and a main chamber  22 , a first sub-chamber  23 , and a second sub-chamber  24  are formed inside the housing  21 . The main chamber  22  is a chamber filled with an adsorbent C made of granular activated carbon or the like, and the first sub-chamber  23  and the second sub-chamber  24  are provided on both sides of the main chamber  22 . The main chamber  22 , the first sub-chamber  23 , and the second sub-chamber  24  are partitioned by partition walls  25  including vents, and the main chamber side surfaces of the partition walls  25  are covered with filters  26  made of non-woven fabric or the like. Accordingly, the adsorbent C is prevented from being dropped out through the vents of the partition walls  25 . 
         [0035]    The purge port  20   p  is formed in the upper portion of the first sub-chamber  23 , and a vapor pipe  35  is connected to the lower portion of the first sub-chamber  23 . In addition, the atmosphere port  20   e  is formed in the upper portion of the second sub-chamber  24 . As illustrated in  FIG. 4 , the purge port  20   p  is configured to the inserted in the axial direction (from below) to be connected to the port receiving portion  132  of the purge port connection portion  130  formed in the upper shell  12 , and an O-ring  20   k  which is a seal material is fitted to the outer peripheral surface of the purge port  20   p.  In addition, the atmosphere port  20   e  is configured to be inserted in the axial direction (from below) to be connected to the port receiving portion (not shown) of the atmosphere port connection portion  140  formed in the upper shell  12 , and an O-ring  20   q  (see  FIG. 1 ) which is a seal material is fitted to the outer peripheral surface of the atmosphere port  20   e.    
         [0036]    Here, in  FIG. 1 , in order to intelligibly show the actions of the canister  20 , the main chamber  22  is expressed in a linear shape. However, the actual, main chamber  22  is formed in a substantially U-shape on the plane as illustrated in  FIG. 3 , and the purge port  20   p  and the atmosphere port  20   e  are adjacent to each other. 
         [0037]    The vapor pipe  35  is a pipe that guides the fuel vapor generated in the tank body  10   m  to the canister  20 , and as illustrated in  FIG. 2 , a fill-up regulating valve  37  is provided at an intermediate position of the vapor pipe  35 . In addition, a cut-off valve  38  is provided at the tip position of the vapor pipe  35 . 
         [0038]    The fill-up regulating valve  37  is a valve which prevents the fuel in the tank body  10   m  from flowing into the vapor pipe  35  to supress a rise in a fuel liquid level in the tank body  10   m.  That is, the fuel liquid level in the tank body  10   m  does not rise to exceed the fill-up regulating valve  37 . As illustrated in the schematic diagram of  FIG. 4C , the fill-up regulating valve  37  includes a valve housing  37   c  and a float type valve body  37   f  housed in the valve housing  37   c.  In the valve housing  37   c,  a tank side opening  37   e  which communicates with the inside of the tank body  10   m  is formed at the bottom portion, and a pipe side opening  37   p  which communicates with the vapor pipe  35  is formed at the ceiling portion. In addition, the valve body  37   f  is configured in be able to close the pipe side opening  37   p  of the valve housing  37   c  in a state where the float type valve body  37   f  floats on the fuel. 
         [0039]    Therefore, in the case where the fuel liquid level in the fuel tank  10  is lower than the fill-up regulating valve  37 , the float type valve body  37   f  is placed on the bottom portion (lower limit position ) of the valve housing  37   c  such that the pipe side opening  37   p  of the fill-up regulating valve  37  is open. Accordingly, the fuel vapor in the tank body  10   m  may be guided to the canister  20  from the fill-up regulating valve  37  and the vapor pipe  35 . 
         [0040]    In addition, in a case where the fuel liquid level in the fuel tank  10  is at the position of the fill-up regulating valve  37 , that is, in a case where the fuel flows into the valve housing  37   c  of the fill-up regulating valve  37 , the valve body  37   f  floats in the valve housing  37   c,  and thus the pipe side opening  37   p  is closed by the valve body  37   f . Accordingly, the fuel in the tank body  10   m  does not flow into the vapor pipe  35 . 
         [0041]    The cut-off valve  38  is positioned at a position higher than the fill-up regulating valve  37  and is typically held in an open state. However, the cut-off valve  38  is configured to be closed during an overturning of a vehicle or the like so as to prevent the fuel in the tank body  10   m  from flowing into the vapor pipe  35  at this time. 
         [0042]    The vapor pipe  35 , the fill-up regulating valve  37 , and the cut-off valve  38  are integrated with the canister  20 , and the height position of the canister  20  is set to a position higher than the vapor pipe  35 . Therefore, the fuel liquid level in the tank  10   m  does not reach the position of the canister  20  even when the fuel tank is filled up. 
         [0043]    That is, the fill-up regulating valve  37  and the cut-off valve  38  correspond to inflow prevention valves of the present invention. 
         [0044]    On the side surface of the housing  21  of the canister  20 , the plurality of claw receiving portions  20   r  are formed in the peripheral direction of the housing  21 . As illustrated in  FIGS. 4A and 4B , the claw receiving portions  20   r  are positioned at position corresponding to the respective claw portions  120  on the rear surface of the upper shell  12 , and are formed in a flat gate shape. As illustrated in  FIG. 4B , in a state where the claw receiving portions  20   r  are transversely held, both ends of the claw receiving portion  20   r  are joined to a side surface  21   z  of the housing  21  of the canister  20 . Accordingly, a slit-shaped opening  20   y  through which the claw portion  120  of the upper shell  12  passes is formed between the claw receiving portion  20   r  and the side surface  21   z  of the housing  21 . That is, a length dimension of the slit-shaped opening  20   y  is set to be approximately the same as width dimensions of the flat plate portion  122  of the claw portion  120  and the hook portion  124 , and a width dimension of the slit-shaped opening  20   y  is set to be approximately the same as a thickness dimension of the stepped portion  125  of the claw portion  120 . 
         [0045]    When the claw portion  120  of the upper shell  12  is inserted into the slit-shaped opening  20   y  of the claw receiving portion  20   r  of the canister  20 , and inclined surface  124   k  of the hook portion  124  of the claw portion  120  abuts on the claw receiving portion  20   r  and slides. Accordingly, the hook portion  124  of the claw portion  120  is displaced from the position of the claw receiving portion  20   r  toward the side surface  21   z  of the housing  21 , and the flat plate portion  122  of the claw portion  120  is elastically deformed toward the side surface  21   z  of the housing  21 . In addition, in a stage in which the hook portion  124  of the claw portion  120  passes through the claw receiving portion  20   r , the flat plate portion  122  of the claw portion  120  returns to its original state (widens outward) by the elastic force, and the stepped portion  125  of the claw portion  120  is caught on the claw receiving portion  20   r . In this state, engagement between the claw portion  120  of the upper shell  12  are respectively engaged in the plurality of claw receiving portions  20   r  of the canister  20 , the purge port  20   p  and the atmosphere port  20   e  of the canister  20  are respectively inserted into the purge port connection portion  130  and the atmosphere port connection portion  140  of the upper shell  12  to be connected, thereby completing mounting of the canister  20 . 
         [0046]    That is, the claw portion  120  corresponds to an engaging portion of the present invention, and the claw receiving portion  20   r  corresponds to an engaged portion of the present invention. 
       &lt;Summary Method of Manufacturing Fuel Tank  10 &gt; 
       [0047]    First, the canister  20  which has been subjected to a product inspection is mounted to the upper shell  12 . When the canister  20  is mounted to the upper shell  12 , the purge port  20   p  and the atmosphere port  20   e  of the canister  20  are respectively aligned with the purge port connection portion  130  and the atmosphere port connection portion  140  of the upper shell  12 . Furthermore, the plurality of claw receiving portions  20   r  of the canister  20  are aligned with the plurality of claw portions  120  of the upper shell  12 . Next, the claw portions  120  of the upper shell  12  are respectively inserted into the slit-shaped openings  20   y  provided in the claw receiving portions  20   r  of the canister  20 , and the claw receiving portions  120  of the the upper shell  12  are respectively engaged with the claw receiving portions  20   r  of the canister  20 . Here, insertion and connection of the purge port  20   p  and the atmosphere port connection port  140  of the upper shell  12  are simultaneously performed. In addition, in a state where the engagements between the claw portions  120  of the upper shell  12  and the claw receiving portions  20   r  of the canister  20  are completed, connections between the purge port  20   p  and the atmosphere port  20   e  of the canister  20  and the purge port connection portion  130  and the atmosphere port connection portion  140  of the upper shell  12  are completed, thereby ending mounting of the canister  20  to the upper shell  12 . 
         [0048]    Next, after a fuel pump or the like of which the illustration is omitted is mounted to the bottom portion of the lower shell  14 , the flange portion  12   f  of the upper shell  12  and the flange portion  14   f  of the lower shell  14  are heated such that the flange portion  12   f  of the upper shell  12  and the flange portion  14   f  of the lower shell  14  are heat-infused to each other. Accordingly, the fuel tank is completed. 
       &lt;Actions of the Fuel Tank&gt; 
       [0049]    Next, the actions of the fuel tank  10  according to the embodiment will be simply described. 
         [0050]    In a stopped state of engine E, when the internal pressure of the fuel tank  10  is increased due to a temperature rise, gas (fuel+air) in the fuel tank  10  flows into the canister  20  through the fill-up regulating valve  37  and the vapor pipe  35 . The fuel vapor that flows into the canister  20  diffuses into the main chamber  22  from the first sub-chamber  23  illustrated in  FIG. 1 , and is adsorbed to the adsorbent C in the main chamber  22 . In addition, air from which the fuel vapor is removed diffuses to the outside from the second sub-chamber  24  and the atmosphere port  20   e  (the atmosphere port connection portion  140 ). In addition, in the stopped state of the engine E, when the internal pressure of the fuel tank  10  is reduced sue to a temporary drop (becomes a negative pressure), the outside air is introduced into the canister  20  from the atmosphere port  20   e  or the like and is supplied into the fuel tank  10 . 
         [0051]    In addition, during fueling, gas, (fuel vapor+air) in the fuel tank  10  flows into the canister  20  through the fill-up regulating valve  37  and the vapor pipe  35 . The fuel vapor that flows into the canister  20  flows into the main chamber  22 . In addition, air from which the fuel vapor is removed diffuses to the outside from the second sub-chamber  24  and the atmosphere port  20   e  (the atmosphere port connection portion  140 ). 
         [0052]    In addition, when the inside of the intake pipe W becomes a negative pressure due to driving of the engine E, the inside of the canister  20  becomes a negative pressure via the purge pipe  11   p  and the purge port connection portion  130  (the purge port  20   p ). Accordingly, after the air flows into the canister  20  from the atmosphere port  20   e  (the atmosphere port connection portion  140 ) and the air passes through the main chamber  22 , the air is supplied into the intake pipe W of the engine E via the purge port  20   p  and the purge pipe  11   p . In addition, the fuel vapor that is adsorbed to the adsorbent C when the air passes through the main chamber  22  is purged and desorbed from the adsorbent C, and the fuel vapor that is desorbed is supplied into the intake pipe W of the engine E along with the air. 
       &lt;Advantages of Fuel Tank  10  According to This Embodiment&gt; 
       [0053]    According to the fuel tank  10  of this embodiment, as the claw receiving portions  20   r  of the canister  20  are engaged with the claw portions  120  of the upper shell  12 , the canister  20  is mounted on the upper shell  12 . The upper shell  12  is then joined with the lower shell  14 , thereby forming the fuel tank  10 . 
         [0054]    In this manner, since the canister  20  is configured to be mounted to the upper shell  12  by the action of engagement between the claw receiving portions  20   r  and the claw portions  120 , the canister  20  is able to be separately subjected to a product inspection before being mounted to the upper shell  12 . In addition, the canister  20  is also detachable by disengaging the claw receiving portions  20   r  of the canister  20  from the claw portions  120  of the upper shell  12 . 
         [0055]    In addition, since the canister  20  is mounted to the inside of the tank body  10   m , even in a case where the fuel vapor permeates the canister  20 , the fuel vapor does not leak out to the atmosphere. Furthermore, compared to a case where the canister  20  is mounted to the outside of the tank body  10   m , the shape of the fuel tank  10  is not complex. 
         [0056]    In addition, since the vapor pipe  35  and inflow regulating valves (the fill-up regulating valve  37  and the cut-off valve  38 ) are integrated with the canister  20  and are mounted to the inside of the tank body  10   m , the fuel vapor that leaks out from the vapor pipe  35  and the like does not leak out to the atmosphere. 
         [0057]    In addition, the atmosphere port  20   e  and the purge port  20   p  of the canister  20  are configured to be able to be inserted into the atmosphere port connection portion  140  and the purge port connection portion  130  formed in the upper shell  12  so as to be connected thereto when the claw receiving portions  20   r  of the canister  20  are engaged with the claw portions  120  formed on the inner wall surface of the upper shell  12 . Therefore, connections between the atmosphere port  20   e  and the purge port  20   p  of the upper shell  12  and the atmosphere port  20   e  and the purge port  20   p  of the canister  20  are facilitated. 
         [0058]    In addition, since the canister  20  is mounted to the inside of the upper shell  12  at the position higher than the upper limit position of the fuel liquid level, a space where the fuel vapor is accumulated in the tank body  10   m  may be reduced by the volume of the canister  20 , and the amount of the fuel vapor generated may be reduced. In addition, since the canister  20  is housed in a space part inside the tank body  10   m , the amount of stored fuel is not reduced. 
       &lt;Modification Example&gt; 
       [0059]    Here, the present invention is not limited to the above-described embodiment, and may be modified in a scope that does not depart from the gist of the present invention. For example, in this embodiment, an example in which the fill-up regulating valve  37  is provided at the intermediate position of the vapor pipe  35  and the cut-off valve  38  is provided at the tip position of the vapor pipe  35 , the fuel vapor in the tank body  10   m  is introduced into the vapor pipe  35  via the fill-up regulating valve  37  or the cut-off valve  38  and is guided into the first sub-chamber  23  of the canister  20  by the vapor pipe  35  is illustrated. 
         [0060]    However, as illustrated in  FIG. 5 , a configuration in which the fill-up regulating valve  37  is omitted and a bidirectional check valve  30  is provided in an inlet portion of the first sub-chamber  23  of the canister  20  is possible. Here, the bidirectional check valve  30  is a protection valve that prevents damage of tank body  10   m  and is typically held in a close state during fueling. Accordingly, during fueling, the air or the like in the tank body  10   m  is not introduced to the canister  20  and is discharged to the outside by a breather line of which the illustration is omitted. 
         [0061]    In addition, in this embodiment, an example in which the vapor pipe  35 , the fill-up regulating valve  37 , and the cut-off valve  38  are integrated with the canister  20  to be mounted to the inside of the upper shell  12  is illustrated. However, as illustrated in  FIGS. 6 to 8 , the vapor pipe  35 , the fill-up regulating valve  37 , and the cut-off valve  38  may be mounted to the inside of the upper shell  12  and the canister  20  may be mounted to the front side of the upper shell  12 . Here,  FIG. 6  is a plan view of the fuel tank according to the modification example,  FIG. 7  is a longitudinal cross-sectional view of the fuel tank, and  FIG. 8  is a side view of the fuel tank. At this time, due to configuration in which the claw portion  120  formed on canister  20 , the canister  20  may be mounted to the upper shell  12  with a single touch. 
         [0062]    In addition, in this embodiment, the claw  120  is exemplified as the engaging portion of the upper shell  12  side, and the claw receiving portion  20   r  is exemplified as the engaged portion of the canister  20  side. However, the claw receiving portion  20   r  may also be formed on the upper shell  12  side as the engaging portion of the claw portion  120  may also be formed on the canister  20  side as the engaged portion. 
         [0063]    Furthermore, the engaging and the engaged portions are not limited tot he forms of this embodiment as long as one or both are attachable and detachable through elastic deformation. 
       REFERENCE SIGNS LIST 
       [0000]    
       
           10   m  tank body 
           12  upper shell 
           14  lower shed 
           20  canister 
           20   p  purge port 
           20   e  atmosphere port 
           20   r  claw receiving portion (engaged portion) 
           21  housing 
           35  vapor pipe (vapor passage) 
           37  fill-up regulating valve (inflow prevention valve) 
           38  cut-off valve (inflow prevention valve) 
           120  claw portion (engaging portion) 
           130  purge port connection portion 
           140  atmosphere port connection portion