CROSS REFERENCES TO RELATED APPLICATIONS 
       [0001]    The present application claims priority under 35 U.S.C. §119 to Japanese Patent Application No. 2015-059426, filed Mar. 23, 2015, entitled “Vehicle With Load-Carrying Platform,” the contents of which are incorporated herein by reference in their entirety. 
       TECHNICAL FIELD 
       [0002]    The present invention relates to a vehicle with a load-carrying platform that provides the load-carrying platform in a rear portion. 
       BACKGROUND ART 
       [0003]    Among vehicles provided with a load-carrying platform in a rear portion, a vehicle is known that provides a load-carrying platform extension means referred to as a bed extender to the load-carrying platform in order to increase a carrying capacity of the load-carrying platform. 
         [0004]      FIGS. 1 and 2  illustrate a known bed extender. As shown in  FIG. 1 , the vehicle is provided with the load-carrying platform in the rear portion, and this load-carrying platform is provided with a front-portion standing plate  123 , one side-portion standing plate  125 , another side-portion standing plate  127 , a tailgate  137 , and a bed extender  111 . In  FIG. 1 , the bed extender  111  is placed in a stowed position. 
         [0005]    From this state, the bed extender  111  is inversely moved  180 ° with a fulcrum portion  191  as a rotation center. 
         [0006]    As a result, as illustrated in  FIG. 2 , the bed extender  111  rests on the tailgate  137  in an opened state. The bed extender  111  is fixed to the tailgate  137  by a lock mechanism  149 . 
         [0007]    Due to a difference in weight between the tailgate  137  and the bed extender  111 , the tailgate  137  and the bed extender  111  exhibit different behaviors during travel. When the behaviors differ, a load on the lock mechanism increases. Increasing a rigidity of the lock mechanism  149  to handle the increase in the load invites enlargement and weight increasing of the lock mechanism  149 . 
         [0008]    In seeking weight reduction of the vehicle, a structure is sought that handles the difference in behaviors between the tailgate  137  and the bed extender  111  without inviting enlargement of the lock mechanism. 
       SUMMARY 
       [0009]    The present invention has as a task to provide a vehicle with a load-carrying platform that can mitigate a load on an elastic band (corresponding to the conventional lock mechanism) that affixes a bed extender to a tailgate. 
         [0010]    In one embodiment, a vehicle with a load-carrying platform includes a load-carrying platform that is provided in a vehicle rear portion and has a tailgate that can open and close; and a bed extender that has both ends axially supported by a side gate provided to the load-carrying platform, the bed extender being rotatable between a stowed state in contact with the load-carrying platform and an extended state in contact with the tailgate in an open position, the extended state effectively extending a load-carrying space in the vehicle rear portion to include the open tailgate. An elastic band is provided so a rear portion of the tailgate and a rear portion of the bed extender enter a tensioned state when the bed extender is in the extended state. A regulating cord is provided that regulates the elastic band from stretching beyond a predetermined distance. A rotation regulation mechanism is provided to the tailgate and the bed extender that regulates further rotational movement by the tailgate and the bed extender making contact when the tailgate closes. 
         [0011]    In some aspects of embodiment, the rotation regulation mechanism can be made from a gate-side stopper member that is connected to the tailgate and has a front-facing stopper surface and an extender-side stopper member that is connected to the bed extender and has a rear-facing stopper surface. The bed extender can be connected to the tailgate and have a predetermined space opened between the front-facing stopper surface and the rear-facing stopper surface. 
         [0012]    In further aspects, the gate-side stopper member can be integrally formed with a wire bracket that holds the tailgate in the open position. 
         [0013]    In further aspects, the rotation regulation mechanism can include an elastic member that abuts either the front-facing stopper surface or the rear-facing stopper surface. 
         [0014]    In still further aspects, the gate-side stopper member can be further integrally formed with an installation portion of the elastic band. 
         [0015]    In still further aspects, the gate-side stopper member can be provided in correspondence to a diagonal surface formed in a corner portion between a rear surface of the bed extender and a side surface of the bed extender on the left or right. The gate-side stopper can be provided on an upper surface of the tailgate. 
         [0016]    In other aspects, the extender-side stopper member can be provided on a rear surface of a member positioned downward when the bed extender is in its extended state. 
         [0017]    In further aspects, the extender-side stopper member can be provided on a chamfered portion formed in a corner portion between a rear surface of the bed extender and a side surface of the bed extender on the left or right. The extender-side stopper member can include a plate bent in an L-shape. 
         [0018]    In another embodiment, a bed extender system for a vehicle with a load-carrying platform can include an extender-side stopper member that is connected to the bed extender and has a rear-facing stopper surface, an elastic member, and a gate-side stopper member having a front-facing stopper surface. The gate-side stopper member can be configured to mount to a vehicle surface and abut the elastic member, the elastic member further abutting the extender-side stopper member to regulate rotation of the bed extender. 
         [0019]    In further aspects, the gate-side stopper member can be further integrally formed with an installation portion for the elastic band. 
         [0020]    In further aspects, the extender-side stopper member can be provided on a rear surface of a member positioned downward when the bed extender is in its extended state. 
         [0021]    In further aspects, the extender-side stopper member can be provided on a chamfered portion formed in a corner portion between a rear surface of the bed extender and a side surface of the bed extender on the left or right. 
         [0022]    In further aspects, the extender-side stopper member can include a plate bent in an L-shape. 
         [0023]    In further aspects, the gate-side stopper member is integrally formed with a wire bracket for being connected to a tailgate configured to move between a closed position and an open position, and wherein the wire bracket is configured to hold the tailgate in the open position. 
         [0024]    In still further aspects, the rotation regulation mechanism can be configured to regulate further rotational movement by the tailgate and the bed extender making contact when the tailgate closes. 
         [0025]    In yet another embodiment, a rotation regulation mechanism for a bed extender of a vehicle with a load-carrying platform can include an extender-side stopper member with a rear-facing stopper surface, the extender-side stopper member configured for attachment to the bed extender; an elastic member; and a gate-side stopper member having a front-facing stopper surface, the gate-side stopper member configured for attachment to a tailgate of the vehicle and to abut the elastic member, the elastic member further abutting the extender-side stopper member to regulate motion of the stopper members, the bed extender and the tailgate. 
         [0026]    In further aspects, the gate-side stopper member can be integrally formed with an installation portion configured to receive an elastic band. 
         [0027]    In further aspects, the extender-side stopper member can include a plate bent in an L-shape. 
         [0028]    Various advantages of embodiments of the invention may be realized. For example, where the bed extender is fixed to the tailgate by the elastic band, both can be continuously placed in the tensioned state to suppress generation of noise due to rattling. Independent movements of the bed extender relevant to the tailgate can be regulated by the regulating cord even with regard to excessive movement while optimizing a tension load. The bed extender and the tailgate can be prevented from rotating in the same direction by the rotation regulation mechanism. 
         [0029]    In embodiments where the predetermined space is opened in a connected state, the weight of the bed extender is not applied to the gate-side stopper member. Because the gate-side stopper member does not have to bear the weight of the bed extender, its size can be significantly reduced. 
         [0030]    In some embodiments, an impact force generated in conjunction with interference can be absorbed by the elastic member, greatly reducing noise. 
         [0031]    In embodiments where the gate-side stopper member is integrally formed with the wire bracket, and optionally further integrally formed with the installation portion of the elastic band, different components share fixtures. By sharing fixtures, a component count can be reduced, costs can be reduced, and assembly properties can be improved. 
         [0032]    In embodiments where the extender-side stopper member is provided on the rear surface below the fulcrum portion of the bed extender, the stopper member can efficiently regulate return rotation movement by the bed extender. 
         [0033]    Embodiments with particular designs for the extender-size stopper member can simplify configuration, reduce costs, and eliminate projection. 
         [0034]    Other benefits of the features described herein will be recognized by those of skill in the art. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWING(S) 
         [0035]      FIG. 1  illustrates a prior art bed extender in a stowed state. 
           [0036]      FIG. 2  illustrates the prior art bed extender in an extended state. 
           [0037]      FIG. 3  is a perspective view of a rear portion of a vehicle with a load-carrying platform according to the present disclosure. 
           [0038]      FIG. 4  is a plan view of a bed extender. 
           [0039]      FIG. 5  is a partial enlarged view of  FIG. 3 . 
           [0040]      FIG. 6  is a plan view of a gate-side stopper member. 
           [0041]      FIG. 7  is a line  7 - 7  cross-sectional view of  FIG. 6 . 
           [0042]      FIGS. 8A-8C  are operational views of a rotation regulation mechanism. 
       
    
    
     DETAILED DESCRIPTION 
       [0043]    As illustrated in  FIG. 3 , a vehicle with a load-carrying platform  10  is provided with side gates  12 ,  12  on the left and right on a load-carrying platform  11  and a tailgate  13  of a rear portion of the vehicle, which may for example be a bed associated with a multi-utility vehicle (an “MUV”) or a pickup truck. Although the illustrations herein are consistent with the vehicle being an MUV or a pickup truck having a bed, it will be understood that any vehicle having a load-carrying platform and tailgate as described herein may be consistent with the disclosure. The tailgate  13  is supported by the load-carrying platform  11  or lower portions of the side gates  12 ,  12  with a hinge pin  14  and is made to open from a standing position to a horizontal position. In the diagram, the tailgate  13  is opened to a horizontal position and suspended by a gate wire  15 . 
         [0044]    Additionally, a bed extender  20  is connected to a rear portion of the side gate  12 . The bed extender  20  is axially supported by the side gates  12 ,  12  at fulcrum portions  16 ,  16 . 
         [0045]    The bed extender  20  in a stowed state resting on the load-carrying platform  11  comes to rest on the tailgate  13  by being inverted with the fulcrum portions  16 ,  16  as rotation centers. This position, illustrated in  FIG. 3 , represents the extended state for the bed extender  20 . In the extended state, the total area available for placing items on the bed is increased to include the area of the tailgate  13 , thus effectively extending the load-carrying platform  11 . 
         [0046]    While the bed extender  20  may be of any shape, an exemplary shape as illustrated in  FIG. 3  is a fence whose main elements are four posts  21  to  24  and an upper pipe  25 , a middle pipe  26 , and a lower pipe  27  bridging the posts  21  to  24 . The upper pipe  25 , the middle pipe  26 , and the lower pipe  27  have front end portions linked by linking plates  28 ,  28 . Extending plates  29 ,  29  are extended from both ends of the middle pipe  26  and these extending plates  29 ,  29  are linked to the side gates  12 ,  12  at the fulcrum portions  16 ,  16 . 
         [0047]    A vibration-dampening cap  46  can be installed at one end of the posts  21  to  24 . The cap  46  may be made of an elastic substance such as soft plastic or rubber in order to act to dampen the vibrations at the interface between the load-carrying platform  11  and the posts  21  to  24  when the bed extender  20  is stowed. Similarly, another vibration-dampening end cap  47  can be installed on the other end of the posts  21  to  24  that abuts an upper surface of the tailgate  13  when the bed extender  20  is in the extended state. 
         [0048]    As illustrated in  FIG. 4 , the four posts  21  to  24  can be square pipes. The four posts  21  to  24  can be channels (channel steel) or angles (angled steel). 
         [0049]    The upper pipe  25  can be made from a transverse portion  31  that extends in a vehicle-width direction; chamfered portions  32 ,  32  that extend diagonally forward from both ends of this transverse portion  31 ; and extending portions  33 ,  33  that extend to a vehicle front from respective tips of these chamfered portions  32 ,  32 . The middle pipe  26  and the lower pipe  27  can be similarly apportioned. 
         [0050]    As shown, the chamfered portions  32 ,  32  are provided between a rear surface of the bed extender  20  and side surfaces of the bed extender  20  on the left and right. As a result, triangular spaces  34 ,  34  made by connecting the rear surface of the bed extender  20  and the side surfaces of the bed extender  20  on the left and right are formed in the corner portions. 
         [0051]    As illustrated in  FIG. 3 , an elastic band  36  (not seen on a post  24  side) extends from the posts  21 ,  24 , and a lower end of this elastic band  36  is detachably hooked to a band installation portion  37  provided on a tailgate  13  side. A rotation regulation mechanism  50  is provided near this band installation portion  37 . Details of this rotation regulation mechanism  50  are described below. 
         [0052]    As illustrated in  FIG. 5 , the elastic band  36  extends from the post  21 . The elastic band  36  includes a band main body  38  made of a elastic material such as rubber; rings  39 ,  41  connected to upper and lower ends of the band main body  38 ; and a regulating cord  42  passed through the pair of rings  39 ,  41 . The regulating cord  42  is made of a material of higher tensile strength and lower elasticity than the band main body  38 . In some implementations, both the regulating cord  42  and rings  39 ,  41  may be made of metal. The regulating cord  42  is set to be longer than a free length of the band main body  38  and is tensioned when the band main body  38  stretches to a predetermined distance, thereby regulating further stretching. By this regulation, the band main body  38  does not stretch in excess of a permissible range. 
         [0053]    The elastic band  36  has the ring  39  on an upper side fixed to the post  21  using an oval fixing plate  43 . The oval fixing plate  43  is fixed to the post  21  with two fasteners  44 ,  44 , one each above and below the metal ring  39 . Each fastener  44  may be, for example, a screw or bolt. The oval fixing plate  43  is affixed securely to withstand the pull of the ring  39  away from the post  21 . 
         [0054]    The rotation regulation mechanism  50  comprises a gate-side stopper member  51  installed on the tailgate  13  side and an extender-side stopper member  65  installed on the bed extender  20  side. 
         [0055]    The gate-side stopper member  51  has integrated on a rear portion the band installation portion  37  of a tongue shape that detachably hooks the metal ring  41  on the bottom. Moreover, the gate-side stopper member  51  has integrated on a front portion a wire bracket  52  that locks a lower end of the gate wire  15 . 
         [0056]    The vibration-dampening cap  47  is on the other end (lower end in this diagram) of the posts  21  to  24  and secures a predetermined space (space D in  FIG. 6 ) against a tensile force of the elastic band  36 . 
         [0057]    As illustrated in  FIG. 6 , the gate-side stopper member  51  is made from a base portion  54  that is provided with bolt holes  53 ,  53  separated in the vehicle-width direction through which bolts that are fixed to the tailgate  13  are passed; the wire bracket  52  that is formed bent upward on a vehicle-width-direction outer side of this base portion  54 ; a standing wall portion  55  that is raised from the base portion  54 ; and a main body portion  56  that extends in the rearward direction from an upper end of the standing wall portion  55 . 
         [0058]    The main body portion  56  is integrally formed with the tongue-shaped band installation portion  37 . A lower end portion of the gate wire  15  that supports the tailgate is locked by a bolt  57  to the wire bracket  52 . 
         [0059]    The surface  58  of the standing wall portion  55  that is facing the front of the vehicle acts as a stopper surface  58 . In this example, an elastic member  59  that protrudes further forward is attached to the front-facing stopper surface  58 . Because an external force to the vehicle rear is applied to the standing wall portion  55 , the standing wall portion  55  is reinforced by bridging a stay  61  between the base portion  54  and the standing wall portion  55  and bridging a stay  62  between the standing wall portion  55  and the main body portion  56 . The elastic member  59  may be provided on a rear-facing stopper surface  67 . 
         [0060]    Furthermore, the extender-side stopper member  65  is connected to a rear surface  27   a  of the lower pipe  27 . This extender-side stopper member  65  is made from a bent plate  66  in an L-shape in a plan view, and a rear surface becomes the rear-facing stopper surface  67 . The L-shape may be a V-shape. 
         [0061]    The gate-side stopper member  51  and the extender-side stopper member  65  comprising the rotation regulation mechanism  50  of the form described above are disposed in the triangular space  34  illustrated in  FIG. 4 . The extender-side stopper member  65  is installed on the chamfered portion  32 , and the gate-side stopper member  51  is provided in correspondence to a diagonal surface (rear surface  27   a ) formed in the corner portion. 
         [0062]    The rotation regulation mechanism  50  is housed in the triangular space  34 , and the rotation regulation mechanism  50  does not protrude sideways from the side surface of the bed extender  20 . 
         [0063]    As illustrated in  FIG. 7 , the predetermined space D is set between the rear-facing stopper surface  67  and the elastic member  59 . 
         [0064]    Note that the elastic member  59  may be omitted. If omitted, the predetermined space D is set as between the rear-facing stopper surface  67  and the front-facing stopper surface  58 . 
         [0065]    Because the predetermined space D is set, a weight of the bed extender  20  is not applied to the gate-side stopper member  51 , a rigidity of the gate-side stopper member  51  can be decreased, and reducing a weight of the gate-side stopper member  51  can be easily achieved. 
         [0066]    An operation of the rotation regulation mechanism  50  of the present invention is next described. 
         [0067]    As illustrated in  FIG. 8A , the tailgate  13  is put in an opened state by being turned around the hinge pin  14 . Meanwhile, the bed extender  20  is inverted around the fulcrum portion  16  to rest on the tailgate  13 . While omitted in this diagram, the ring  41  of the elastic band  36  is locked to the band installation portion  37 . 
         [0068]    Note that the extender-side stopper member  65  is provided on the rear surface  27   a  of a member (the lower pipe  27  in this example) positioned downward in a usage time when the bed extender  20  is inverted relative to the fulcrum portion  16  provided on the side gate  12 , that is, below the fulcrum portion  16 . 
         [0069]    Because of this, a first line  72  that passes through a first point  71  on the rear-facing stopper surface  67  and the fulcrum portion  16  extends downward to the vehicle rear. Moreover, a second line  74  that passes through a second point  73  on the front-facing stopper surface (elastic member  59 ) and the hinge pin  14  extends upward to the vehicle rear. 
         [0070]      FIG. 8B  is a view that excerpts the first and second lines  72 ,  74  at the usage time (more precisely, a usage commencement time), and the predetermined space D exists between the first point  71  and the second point  73 . When travel is commenced, due to an influence from unevenness of a road surface or the like, the vehicle may sway up and down. In conjunction with this swaying, the second point  73  on the tailgate  13  side rises along an arc line  75  around the hinge pin  14 . Meanwhile, the first point  71  on the bed-extender  20  side rises along an arc line  76  around the fulcrum portion  16 . 
         [0071]    Because the second point  73  is above the hinge pin  14 , when rising, it moves to the vehicle front. Meanwhile, because the first point  71  is below the fulcrum portion  16 , it first moves to the vehicle rear and then starts to move to the vehicle front once it moves above the fulcrum portion  16 . 
         [0072]    In an initial period of rising, the first point  71  and the second point  73  move so as to approach each other. 
         [0073]    As a result, as illustrated in  FIG. 8C , the rear-facing stopper surface  67  and the front-facing stopper surface  58  abut. 
         [0074]    When these abut, a triangle is formed whose vertices are the first and second points  71 ,  73 ; the fulcrum portion  16 ; and the hinge pin  14 . Because this triangle is structurally rigid, the shape does not change. That is, the first and second points  71 ,  73  do not rise further, and rotation of the side gate  12  and the bed extender  20  is regulated. 
         [0075]    Because rotation is regulated, there is no concern that an excessive force will be applied to the elastic band  36 . As a result, the elastic band  36  can be made compact and lightweight. 
         [0076]    The present invention is favorable in a vehicle with a load-carrying platform provided with a tailgate that can open and close, such as an MUV or pickup truck. 
         [0077]    The foregoing description, for purpose of explanation, has been described with reference to specific embodiments. However, the illustrative discussions above are not intended to be exhaustive or to limit the invention to the precise forms disclosed. Many modifications and variations are possible in view of the above teachings. The embodiments were chosen and described in order to explain the principles of the invention and its practical applications, to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated.
In a vehicle with a load-carrying platform, an elastic band is provided so a rear portion of a tailgate and a rear portion of a bed extender enter a tensioned state. A rotation regulation mechanism is provided to the tailgate and the bed extender that regulates further rotational movement by the tailgate and the bed extender making contact when the tailgate is rotated towards a closed position. The bed extender and the tailgate are prevented from rotating in the same direction by the rotation regulation mechanism, and the load on the elastic band is mitigated.