Abstract:
This invention relates to a windshield unit for a motorcycle which is capable of reducing hissing noises of wind and improving performance of discharging water without detracting from the motorcycle&#39;s appearance while eliminating wind buffeting. The windshield unit includes a wind screen which shields running wind on a cowl disposed on a front portion of the motorcycle body, an air inlet port which guides the running wind to the back side of the wind screen, and an air guide plate which guides air upward and backward from the air inlet port, a step portion with a step on a top surface of the air guide plate that is directed backward and downward to form a drain.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
   This application is based on Japanese Patent Application NO. 2003-070228. 
   FIELD OF THE INVENTION 
   The present invention relates to a windshield unit for a motorcycle that minimizes wind buffeting. 
   BACKGROUND OF THE INVENTION 
   Conventional windshields commonly have a structure in which a front cowl is disposed on a front portion of a motorcycle and includes a screen, otherwise known as a windshield, secured thereto for forward view. This screen protects the rider from running wind, rainwater, and dust. However, the running wind which passes over the screen can generate negative pressure behind the screen, which creates swirling currents in the face of the rider and also right behind the rider. The swirling currents can increase drag as well as make the driver uncomfortable. To solve this problem an air inlet port can be provided in a lower portion of the screen so that air taken in from the air inlet port can be channeled between the screen and an air guide plate disposed behind the screen. The air channeled behind the screen can be joined with the air in front of the screen to prevent negative pressure that causes swirling currents that make the rider uncomfortable. 
   Incidentally, while the above-mentioned air inlet port reduces negative pressure, it also allows rainwater to be channeled behind the screen. Hence, a ridge to block rainwater from reaching the rider can be formed on the air guide plate. The rainwater accumulated on the air guide plate can be gathered to be discharged from a drain formed on the air guide plate (see JP 02-33794). 
   However, in the foregoing conventional windshield, although rainwater can be blocked from going backward by means of the ridge formed on the air guide plate, the ridge generates unpleasant hissing noises as air passes over the ridge. 
   In addition, since the drain used to discharge rainwater is formed on the air guide plate, the functional parts inside the air guide plate can be seen through the drain, thereby degrading the appearance of the motorcycle. 
   This present invention provides a windshield unit for a motorcycle which can, without damaging the motorcycle&#39;s appearance, reduce hissing noises and improve water discharge. 
   BRIEF SUMMARY OF THE INVENTION 
   To solve the aforementioned problems, a windshield unit for a motorcycle where a screen which shields running wind is provided on a cowling disposed on a front portion of a motorcycle. An air inlet port which guides the running wind to a back side of the screen is formed and an air guide plate which guides the running wind upward and backward from the air inlet port is also provided. A step portion is formed on a top surface of the air guide plate and is directed backward and downward. The step portion is disposed along a body width direction and includes a sidewall that is opened to form a drain. 
   The invention enables running wind to be guided from the air inlet port to the back side of the screen along the air guide plate. Liquid left on the air guide plate is guided backward along the air guide plate step portion and discharged through opened drains in the sidewalls of the step portions. 
   In one embodiment, the step portion is provided at a joint portion between the air guide plate and a separate member disposed adjacent to the air guide plate. In this embodiment, the step portions are covered by the separate member and are thus hidden from plain view. 
   In another embodiment, the separate member disposed adjacent to the air guide plate is extended above the step portion of the air guide plate. In this embodiment, air-flow shifting operations by the separate member against running wind passing through the step portions can be exhibited, and, at the same time, the step portions can be covered by the separate member. 
   In yet another embodiment, a rib (for example, a rib  71 ) extending in a longitudinal direction of the body at the step portion is provided. The rib restricts movement of raindrops along the inclination of the body in the right and left directions of the body. Moreover, the ribs can be effectively utilized as the positioning members in the joint portions of the separate member. 
   According to the invention, when running wind guided from the air inlet port to the back side of the screen flows along the air guide plate, raindrops left on the air guide plate are smoothly guided backward along the air guide plate to run into the step portions, and discharged without fail from the opened drains of the sidewalls of the step portions. Therefore, hissing noises of the wind can be limited to the minimum. At the same time, since the drains are not exposed to the outside while the performance of discharging water is ensured, there is an effect that the appearance quality can be improved. 
   Also according to the invention, since the step portions can be covered by a separate member and are thus difficult to see from outside, the motorcycle&#39;s appearance is further improved. Moreover, since the step portions are not exposed to the outside, there is an effect that the degree of freedom in molding the step portions can be increased. 
   In an alternative embodiment of the invention, since the air-flow shifting operation by a separate member against running wind passing through the step portions can be exhibited, hissing noises of the wind can be remarkably reduced. At the same time, since the step portions can be covered by the separate member without fail, the appearance can be further improved. 
   Also, since movement of raindrops along the inclination of the body in the right and left directions of the body can be restricted by the step portions, the raindrops can be efficiently discharged. Moreover, since the ribs can be effectively utilized as the positioning members in the joint portions of a separate member, assembly of the part is made easier. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a side view of a motorcycle of a first embodiment of the present invention. 
       FIG. 2  is a partial perspective view of the motorcycle of the first embodiment. 
       FIG. 3  is a perspective view of dismantled main parts of the first embodiment. 
       FIG. 4  is a plan view of an air guide plate. 
       FIG. 5  is a plan view of a meter-visor. 
       FIG. 6  is a perspective view showing a state of attaching the meter-visor to the air guide plate. 
       FIG. 7  is a sectional view along a line A—A in  FIG. 6 . 
       FIG. 8  is a partial perspective view of the air guide plate. 
       FIG. 9  is an enlarged view of main parts in  FIG. 7 . 
       FIG. 10  is a sectional view of the main parts of alternative embodiment. 
       FIG. 11  is a sectional view of the main parts of alternative embodiment. 
       FIG. 12  is a sectional view of the main parts of alternative embodiment. 
       FIG. 13  is a sectional view of the main parts of still another embodiment. 
       FIG. 14  is a perspective view of a dismantled right item housing chamber. 
       FIG. 15  is a perspective view of a dismantled left item housing chamber. 
       FIG. 16  is a sectional view of the right item housing chamber taken along a C—C line in  FIG. 2 . 
       FIG. 17  is a sectional view of the left item housing chamber taken along a B—B line in  FIG. 1 . 
       FIG. 18  is a plan view of the right item housing chamber. 
       FIG. 19  is a side view of the right item housing chamber. 
       FIG. 20  is a plan view of the left item housing chamber. 
       FIG. 21  is a side view of the left item housing chamber. 
       FIG. 22  is a perspective view showing a state where a lid of the right item housing chamber is opened. 
       FIG. 23  is a front view of a front hinge arm. 
       FIG. 24  is a front view of a rear hinge arm. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Now referring to  FIG. 1 , a first embodiment of this invention will be described with reference to the drawings.  FIG. 1  is a side view of a motorcycle. A body frame  3  of the motorcycle  1  includes a head tube  5 , a main tube  7  extending diagonally rearward from the head tube  5 , a center tube  9  extending downward from the rear end of the main tube  7 , a seat rail  11  extending rearward from the main tube  7 , and the like. Note that  FIG. 1  shows a state where the body is supported by a center stand S. 
   A front wheel  13  is suspended and supported by right and left front forks  19 , each of which is made up of an outer case  15  and an inner case  17 . The top portion of each inner case  17  is supported by a top bridge  21  and a bottom bridge  23 , and a steering stem  25  inserted through the head tube  5  and connected to the top bridge  21  and the bottom bridge  23 . A handle  27  to steer the front wheel  13  is provided on the top bridge  21 . 
   An engine  29  is supported by the main tube  7  and the center tube  9 , a rear wheel  31  is supported through a rear fork  33 , and the rear wheel  31  is driven by the engine through a drive shaft  35 . 
   A fuel tank  37  is provided over the main tube  7 , a seat  39  is provided over the seat rail  11 , and a radiator  41  is provided at the back of the forks  19  at an angle with respect to the front position of the engine  29 . 
   As shown, the motorcycle  1  is a full cowling type two-wheeled vehicle which includes a front cowl (cowling)  43  covering a front portion of the body, a wind screen (screen)  45  mounted on a top portion of the front cowl  43 , a side cowl  47  covering a side portion of the body, a seat cowl  49  covering a bottom portion of the seat  39 , a front fender  51  covering a top portion of the front wheel  13 , and a rear fender  53  covering a top portion of the rear wheel  31 . 
   As also shown in  FIGS. 2 and 3 , a pair of mirror covers  59 , each of which covers a rear-view mirror  55  and includes a turn signal lamp  57 , is mounted at the right and left of the front cowl  43 . An air guide plate  63  which guides upward and backward running wind introduced into an air inlet port  61  opening behind the wind screen  45  is mounted on the upper brim of the front cowl  43 . The air inlet port  61  is formed between the back surface of the wind screen  45  and the air guide plate  63 . Moreover, a meter-visor (separate member)  65  is mounted at the back of the air guide plate  63 , and, at an upper portion of the air guide plate  63 , the wind screen  45  is mounted through a tilt angle changing mechanisms (diagrammatically shown)  67  so that the tilt angle thereof can be changed. A negative pressure region, which is generated in front of the face of the driver due to running wind flowing along the front surface of the wind screen  45 , disappears when running wind flows backward along the air guide plate  63 . Thus, running resistance (drag) is significantly reduced and the driver no longer buffed by the air currents. 
   As shown in  FIGS. 4 and 6 , the air guide plate  63  can be a member in which the bottom edge of a center portion  631  is formed to have a triangle shape and mount portions  632  for the wind screen  45  is formed at the right and left of the center portion  631  such that the mount portions  632  are upheaved from the center portion  631  and protrude downward below the center portion  631 . The center portion  631  is formed to be slightly bent at the upper portion thereof toward a rider (see  FIGS. 6 and 7 ), and a top edge  633  is formed in a smooth arc shape. On the front surface of the mount portions  632 , opening portions  634  for mounting the tilt angle changing mechanisms  67  of the wind screen  45  are formed along a vertical direction. 
   Moreover, top edges  635  of the mount portions  632  are formed to be upheaved from the top edge  633  of the center portion  631 . In other words, the top edge of the center portion  631  is formed in a position lower than the top edges of the mount portions  632  so that the forward view of the center portion  631  can be secured. Note that in the lower portion of the center portion  631 , opening portions  636  which take in running wind to the back side of the air guide plate  63  and introduce the running wind to later-described louvers  653  are formed. 
   At the top edge  633  of the center portion  631  and at portions lying between the top edge  633  and the top edges  635 , step portions  69  are formed. In other words, there are disposed a step portion  691  provided in the body width direction on the center portion  631  and right and left step portions  692  provided in the body width direction from the center portion  631  to the mount portions  632  for the wind screen  45 . 
   As shown in  FIGS. 7 to 9 , each step portion  69  is pulled down backward from the top surface of the air guide plate  63  along a sidewall  693  to form a flat bottom wall  694 . The sidewall  693  at the back of the bottom wall  694  is made open, and this opened back sidewall  693  is formed to be a drain  695 . The step portions  69  and ribs  71  are formed along the longitudinal direction of the body, namely, the front-rear direction. In this embodiment, as shown in  FIGS. 4 and 6 , ribs  711  are formed at four points at predetermined intervals in the step portion  691  of the center portion  631 , and ribs  712  are respectively formed at three points at predetermined intervals in the right and left step portions  692  lying from the center portion  631  to the mount portions  632 . 
   As shown in  FIG. 7 , the air inlet port  61  can be formed between the wind screen  45  and the air guide plate  63 . Since liquid that enters the inlet port  61  generally moves up the air guide plate  63 , the step portions  69  are formed across the body width direction. The right and left step portions  692  include ribs  712  that are formed to slightly face outward.  FIG. 8  shows a state where the right and left step portions  692  are viewed from a side. In addition, the meter-visor  65  shown in  FIG. 6  is disposed adjacent to the back side of this air guide plate  63 , and the air guide plate  63  and the meter-visor  65  are attached by bolts  73  such that the step portions  69  of the air guide plate  63  are positioned at joint portions of the air guide plate  63  with the meter-visor  65 . Note that insertion holes  731  for the bolts  73  and tightening portions  65  are formed on the air guide plate  63  and on the meter-visor  65 . 
   As shown in  FIG. 5 , the top edge of the meter-visor  65  is formed to be in conformity with the top edges  633  and  635  of the air guide plate  63 . In addition, the meter-visor  65  and the air guide plate  63  together are positioned at the back of the wind screen  45 . At the top edge of the meter-visor  65 , there is provided a flange portion  651  formed to be bent inward. This flange portion  651  is extended toward a position along the top surface of the air guide plate  63 . This position is above the step portions  69  of the air guide plate  63 , and faces the bottom wall  694  of the step portion  69 . The flange portion  651  of the meter-visor  65  may be structured to be in contact with the top edges of the respective ribs  71 , whereby the ribs  71  of the air guide plate  63  can function as positioning members for the meter-visor  65 . 
   In the center portion of the meter-visor  65 , a mount hole  652  for a meter unit which is not shown is formed. In the lower right and left portions, a louver  653  is provided on each upper side thereof, and a mount portion  654  for a speaker is formed on the back surface below the louver  653 . 
   In the above described embodiment, the step portions  69  are provided in the joint portions of the air guide plate  63  with the meter-visor  65 . However, other aspects as shown in  FIGS. 10 to 13  are applicable. Note that, in  FIGS. 10 to 13 , the ribs are omitted for convenience of illustration. 
   Shown in  FIG. 10  is the step portion  69  which is not provided in the joint portion of the meter-visor  65  but provided on the upper surface of the air guide plate  63 . Accordingly, costs can be reduced because it is necessary only to process the air guide plate  63 . 
   Moreover, as shown in  FIG. 11 , two drains  695  may be provided in the front and back of the bottom wall  694  by opening the front and back sidewalls  693  of the step portion  69 . Thus, compared to a case where one drain  695  is provided, the ability and performance of discharging water can be improved. 
   Further, as shown in  FIG. 12 , the drains  695  are not limited to the joint portions of the air guide plate  63  with the flange portion  651  of the meter-visor  65  as in the above-described embodiment. The top edge portion of the meter-visor  65  may be extended toward the front side, and the drains  695  of the step portions  69  of the air guide plate  63  may be covered by this top end portion. In other words, the meter-visor  65  does not need to extend up to the position facing the bottom walls  694  of the step portions  69 , and stopped short thereof. Thus, it is advantageous in that the flange portion  651  is not required to be provided on the meter-visor  65 . 
   Furthermore, as shown in  FIG. 13 , also in a case where the flange portion  651  of the meter-visor  65  is extended to the step portions  69  of the air guide plate  63 , the meter-visor  65  does not need to extend up to the portion facing the bottom walls  694 , and is stopped short thereof. 
   With such a structure, compared to a case where the flange portion  651  of the meter-visor  65  is extended up to the position facing the bottom walls  694  of the step portions  69 , larger opening portions can be secured in substance on the top surface of the air guide plate  63 . Hence, the amount of raindrops to be taken in from the step portions  69  can be increased, and the performance of discharging water can be improved. 
   According to the embodiments described above, during driving in the rain or the like, when running wind which is guided from between the back surface of the wind screen  45  and the front cowl  43  and is taken in from the air inlet port  61  between the wind screen  45  and the front surface of the air guide plate  63  flows along the air guide plate  63 , raindrops left on the air guide plate  63  are guided backward along the air guide plate  63  to run into the step portions  69 . Therefore, compared to a case where the raindrops are gathered using a ridge, hissing noises of wind can be reduced significantly. 
   Here, the raindrops which have run into the step portions  69  are discharged without fail from the drains  695  formed by opening the sidewalls  693  of the step portions  69 . Hence, performance of discharging water can be remarkably improved. Moreover, since the flange portion  651  at the edge of the meter-visor  65  is disposed and extended above the step portions  69  of the air guide plate  63 , the drains  695  are not seen through the wind screen  45  or the like. Therefore, interior functional parts are not exposed to the outside, whereby an appearance quality is improved. 
   Further, since the step portions  69  themselves are also difficult to see from outside as they are covered by the flange portion  651  of the meter-visor  65 , the appearance quality is even more improved also in this point. At the same time, since the step portions  69  themselves are not exposed to the outside, there is no restriction on molding, and the step portions  69  can be molded in a shape where optimum performance of discharging water can be exhibited. Thus, degree of freedom in designing can be increased. 
   Furthermore, since the flange portion  651  of the meter-visor  65  is formed and extended above step portions  69  to exhibit air-flow shifting operation against running wind passing through, hissing noises of the wind can be remarkably reduced. 
   In addition, since movement of raindrops along the inclination of the body in the right and left directions of the body can be restricted by the ribs  71  of the step portions  69 , the raindrops can be efficiently discharged. Moreover, if the ribs  71  are effectively utilized as positioning members in the joint portions of the meter-visor  65  when attaching the meter-visor  65 , easiness of fixedly attaching can be improved. 
   Note that, according to this embodiment, the flange portion  651  of the meter-visor  65  is disposed and extended toward a position along the top surface of the air guide plate  63 . This position is above the step portions  69  of the air guide plate  63 , and is facing the bottom wall  694  of the step portions  69 . Hence, since not only the drains  695  but also most of the step portions  69  are covered by the flange portion  651  of the meter-visor  65 , therefore the drains  695  are difficult to see from outside while the performance of discharging water is ensured. Thus the appearance quality can be improved. 
   Note that, this invention is not limited to the above embodiments, and is applicable to scooter type vehicles, for example, as long as a front cowl is provided thereto. 
   As shown by a shaded area surrounded by a dotted line in  FIG. 1  and by a dotted line in  FIG. 2 , item housing chambers  80 ,  81  are respectively provided inside the right and left side cowls  47  at the sides of the fuel tank. 
   As shown in  FIGS. 14 ,  16 ,  18 ,  19  and  22 , the right item housing chamber  80  is integrally formed of an item chamber main body  84  and an upper plate  88  having an opening portion  86 , and mounted to the side cowl  47  and the body by use of screws  90  and washers  92 . To the opening portion  86  of the upper plate  88 , a lid  94  is attached to be able to open and close. This lid  94  is structured to open toward the outside of the vehicle in consideration of that the housed item is taken in and out. 
   To hinge portions  96 ,  98  (shown in  FIGS. 16 ,  18  and  19 ) at the front and rear of the upper plate  88 , the bottom end portion of a front hinge arm  100  at the front side and the bottom end portion of a rear hinge arm  102  at the rear side are rotatably supported by a collar  104  and a screw  106 , respectively. The top end portions of the front hinge arm  100  and the rear hinge arm  102  are protruding upward from opening portions  108 ,  110  formed on the upper plate  88 , respectively, and respective flange portions  112 ,  114  formed on these top end portions are attached on the back surface of the lid  94  by screws  115 . Here, at one side of each of the opening portions  108 ,  110  on the top surface of the upper plate  88 , a recessed escape portion  118  of the respective flange portions  112 ,  114  is formed so that the respective flange portions  112 ,  114  of the respective hinge arms  100 ,  102  do not interfere with the upper plate  88  when the lid  94  is closed. Note that the reference numeral  116  denotes a seal material to be attached to the back surface of the lid  94 . 
   As shown in  FIGS. 15 ,  17 ,  20  and  21 , the left item housing chamber  81  is formed of separated members of an item chamber main body  85  and an upper plate  89  having an opening portion  87 , which are fixedly attached to each other by a screw  91 . The fixedly attached both members are mounted to the side cowl  47  and the body by use of the screws  90  and the washers  92 . To the opening portion  87  of the upper plate  89 , a lid  95  is attached to be able to open and close. The item housing chamber main body  85  has a top opening portion  851  whose shape is different from that of the opening portion  87  of the upper plate  89 , and houses an audio unit  852  which is not taken in and out normally. Operation knobs  853  of the audio unit  852  are protruding from the top opening portion  851  and the opening portion  87  of the upper plate  89  is formed to surround disposed positions of the operation knobs  853 . 
   Thus, by separately structuring the item housing chamber main body  85  and the upper plate  89 , the degree of freedom in selecting an item to be housed can be increased. That is, if the two members are integrally formed, the size of the item to be housed is limited because there is restriction concerning the shape of the opening portion  87  of the upper plate  89 ; however, by separating the two members, the opening portion  87  of the upper plate  89  is required only to function as, for example, an opening necessary for the operation, and thus the size of the item to be housed in the item housing chamber main body  85  does not really matter. 
   Hence, although description has been made by taking the audio unit  852  as an example, the main body unit of a car navigation system can be installed instead of the audio unit  852  on condition that operation of the device is available through the opening portion  87  of the upper plate  89 . Moreover, it is possible to allow the user to select between the audio unit and the car navigation system according to his/her preference. 
   Here, the lid  95  of the left item housing chamber  81  is also structured to open toward the outside of the vehicle in consideration of that the housed items is taken in and out. To hinge portions  97 ,  99  at the front and rear of the upper plate  89 , the bottom end portion of the front hinge arm  100  and the bottom end portion of the rear hinge arm  102  are rotatably supported at the front and rear sides by the collars  104  and the screws  106 , respectively. 
   The top end portions of the front hinge arm  100  and the rear hinge arm  102  are protruding upward from opening portions  109 ,  111  formed on the upper plate  89 , respectively, and respective flange portions  112 ,  114  formed on these top end portions are attached to the back surface of the lid  95  by screws  115 . Here, at one side of each of the opening portions  109 ,  111  on the top surface of the upper plate  89 , a recessed escape portion  118  of the respective flange portions  112 ,  114  are formed so that the respective flange portions  112 ,  114  of the respective hinge arms  100 ,  102  do not interfere with the upper plate  88  when the lid  95  is closed. Here, onto the left item housing chamber  81 , a key cylinder unit  120  is provided. Note that the reference numeral  117  denotes a seal material to be attached to the back surface of the lid  94 . 
   Next, based on  FIGS. 18 ,  19  and  22 , description will be made of the front hinge arm  100  and the rear hinge arm  102  by taking the right item housing chamber  80  as an example. Note that, although the lid  94  is a lid which opens to about 90 degrees when fully opened,  FIG. 18  shows a state where the lid  94  is opened to 180 degrees for convenience of illustration. 
   The lid  94  of the right item housing chamber  80  is formed to have an upwardly convex curve along the top edge portion of the side cowl  47 . This is because the side cowl  47  is formed such that, in order to save a leg space, the top edge thereof gradually slopes from the side of the fuel tank  37  to have steeper inclination as it comes to the rear side, and thus fits along the under-knee part of the driver (see  FIG. 19 ). 
   The lid  94  can be opened and closed by means of the front hinge arm  100  and the rear hinge arm  102 . Since the lid  94  is curved in an upward convex shape, the protruding portions from the hinge portions, that is, over-hung portions OV that are portions protruding from the attaching portions of the flange portions  112 ,  114  of the hinge arms  100 ,  102 , are made close to the upper plate  88  especially at the front side. This is because, since the front side of the side cowl  47  is more flat, the front over-hung portion OV is closer to the upper plate  88  than the rear over-hung portion, which gradually slopes downward. Accordingly, the over-hung portion OV of the lid  94  which is protruding frontward from the front hinge portion  96  is, when the lid  94  is fully opened, namely, when opened to about 90 degrees, as shown as an inner limb L by a dash-dotted line in  FIG. 22 , displaced inwardly to approach a hinge center HC. That is, depending on the lengths of the hinge arms  100 ,  102 , when the lid  94  is opened toward the outside from a closed state, the inner limb L of the lid  94  of the over-hung portion OV may interfere with an outside portion of the upper plate  88 . 
   It goes without saying that, in order to prevent the over-hung portion OV from interference, it is possible to make the front hinge arm  100  and the rear hinge arm  102  long so that both hinge arms  100 ,  102  do not interfere with the upper plate  88 . However, the trajectory of opening/closing the lid  94  is required to be inside of the outer surface of the side cowl  47 . In other words, it is required that the item is easily taken in and out by keeping the lengths of the respective hinge arms  100 ,  102  sufficiently long while the lengths of the respective hinge arms  100 ,  102  are made as short as possible at the same time. 
   In view of the above, in this embodiment, the portion, in the over-hung portion OV on the front hinge arm  100  side, which is displaced inwardly when the lid  94  is fully opened, and the rear hinge arm  102  side, which has little over-hang and a small degree of approaching the upper plate  88 , is made as long as possible but not to protrude toward outside of the side cowl  47  in order to secure the easiness of taking in and out the housed item. Meanwhile, the length of height between the attaching position of the flange portion  112  of the front hinge arm  100  (see  FIG. 23 ) and the hinge center HC (front hinge portion  96 ) at the time of closing the lid  94  (LHF) is made shorter than the length of height between the attaching position of the flange portion  114  of the rear hinge arm  102  (see  FIG. 24 ) and the hinge center HC (rear hinge portion  98 ) (LHR) (LHF&lt;LHR). Thus, interference between the performance of taking in and out the housed item and the lid  94  is prevented. 
   In other words, by placing the front hinge portion  96  higher than the rear hinge portion  98  (making closer to the lid  94 ) as shown in  FIG. 19 , when the respective hinge arms  100 ,  102  are rotated by 90 degrees from a viewpoint of the hinge center HC, the front side of the lid  94  is made to follow a higher rotation trajectory by the difference between the foregoing length LHR and the length LHF, whereby the front side of the lid  94  is set apart from the upper plate  88  by the inwardly displaced portion and thus the interference is prevented. 
   Therefore, degree of freedom in molding the side cowl  47  is secured without restriction due to the right item housing chamber  80 . Note that description will be omitted with respect to the left item housing chamber  81  since it is similar to the above. 
   In this way, the item housing units are structured such that the opening portions  86 ,  87  of the upper plates  88 ,  89  of the right and left item housing chamber  80 ,  81 , which are provided interior of the side cowls  47 ,  47  at the sides of the fuel tank  37  and between the fuel tank  37  and the side cowls  47 ,  47 , can be opened and closed by the lids  94 ,  95 . Here, when the upper plates  88 ,  89  are curved in an upward convex shape, the lids  94 ,  95  are supported, by the front hinge arm  100  and the rear hinge arm  102 , to be able to open and close, and the over-hung portions OV protruding forward from the front hinge portions  96 ,  97  to approach the upper plates  88 ,  89  are formed on the lids  94 ,  95 , in order for the front portions of the lids  94 ,  95  not to interfere with the upper plates  88 ,  89 , the front hinge portions  96 ,  97  are made higher than the rear hinge portions  96 ,  97  (made closer to the lids  94 ,  95 ). Thus, by using a small hinge arm, a sufficient opening for housing can be formed, and there will not be any restriction on molding the side cowl  47 . 
   Here, in this embodiment, respective lengths L(LID)F, L(LID)R from the side edges of the lids  94 ,  95  to the attaching portions of the flange portions  112 ,  114  of the hinge arms  100 ,  102  are made to be L(LID)F&lt;L(LID)R as shown in  FIG. 18 . Thus, it is even more ensured that the front sides of the lids  94 ,  95  do not interfere with the upper plates  88 ,  89 . 
   As a result, as the item housing chamber shown in Japanese Patent Laid-Open Heisei 11-208551, a problem that when the lid of the chamber opens in the vertical direction, for example, a long arm to secure an opening area and a large housing space for this arm are required can be solved. At the same time, the lids  94 ,  95  capable of opening in a horizontal direction with short arms can be applied, and structures where the lids  94 ,  95  do not interfere with parts and items around the lids can be realized. 
   Note that, although description has been made of a case where the over-hung portions OV close to the upper plates  88 ,  89  are protruding toward the front from the front hinge portion  96 ,  97 , the above can be also applied when the over-hung portions OV are protruding backward from the rear hinge portions  98 ,  99 . In this case, the positions of the rear hinge portions  98 ,  99  are set higher than that of the front hinge portions  96 ,  97  to approach the lids  94 ,  95 . 
   In other words, depending on the curving degree of the lid and the length of the over-hung portion, by making the vertical positions of the front and rear hinge portions different from each other, a structure is applicable where the housing spaces of the hinge arms can be set at the minimum while the interference by the lid is prevented.