Patent Publication Number: US-8967649-B2

Title: Motorcycle rear body structure

Description:
CROSS REFERENCE TO THE RELATED APPLICATION 
     This application is based on and claims Convention priority to Japanese patent application No. 2012-276541, filed Dec. 19, 2012, the entire disclosure of which is herein incorporated by reference as a part of this application. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a motorcycle body structure and, more particularly to a rear frame assembly in a motorcycle including a rear fender, overhanging a motorcycle rear wheel, and a rear side cover positioned below a motorcycle seat assembly and on each side of the motorcycle for covering a rear frame assembly of a motorcycle frame structure. 
     2. Description of Related Art 
     In most of the motorcycles, it is well known that a rear fender, disposed on a rear frame assembly of the motorcycle so as to overhang the rear wheel, and a rear side cover, employed on each side of the motorcycle so as to cover that rear frame assembly of the motorcycle, are mounted on a motorcycle frame structure. The rear fender and the rear side cover are mounted on a rear frame portion of the motorcycle frame structure separately and independently of each other and are not connected with each other. In such case, the side covers have their respective rear portions left open in a direction laterally of the motorcycle, resulting in formation of gaps each between the rear fender and the respective side cover. Also, the JP Laid-open Patent Publication No. 2010-083325, for example, suggests the use of a large sized rear fender overhanging the rear wheel in its entirety and side covers both secured to the rear fender by means of bolts. 
     It has, however, been found that although in the motorcycle disclosed in the above described patent document no gap is formed between the rear fender and each of the side covers, the rear fender is so large that the aesthetic appearance of the motorcycle tends to be impaired enough to give out a lumpish sensation and, also, the cost of manufacture of the rear fender tends to increase. 
     SUMMARY OF THE INVENTION 
     In view of the foregoing, the present invention herein disclosed is intended to provide a motorcycle of a kind in which the formation of the gaps between the rear fender and each of the side covers can be suppressed without allowing the rear fender to be increased in size. 
     In order to accomplish the foregoing object of the present invention, there is provided a motorcycle which includes a rear fender overhanging a rear wheel and a side cover concealing a motorcycle frame structure from outside at a location below a rider&#39;s seat, in which the rear fender is disposed rearwardly of the rider&#39;s seat, and the side cover is disposed below the rider&#39;s seat and forwardly of the rear fender. In this motorcycle, the rear fender referred to above has an outer side portion and a fender overlap portion referred to above is formed in a lower portion of the outer side portion of the rear fender. Also, the side cover has a rear portion and a cover overlap portion being formed in a rear portion of the side cover for engagement with the fender overlap portion. One of the fender and cover overlap portions has an engagement portion and the other of the fender and cover overlap portions has a to-be-engaged portion, wherefore the engagement portion is engaged with the to-be-engaged portion to thereby regulate the position of the side cover in leftward and rightward directions. 
     According to the above described construction, since the front portion of the rear fender and a rear portion of the side cover are engaged with each other, opening of the rear portion of the side cover in leftward and rightward direction is suppressed and no gap is formed between the rear fender and the side cover. Also, since the rear portion of the side cover is merely engaged with the front portion of the rear fender, there is no need that the rear fender should be extended forwards and should be overlapped on and bolted to the side cover, and, therefore, an increase in size of the rear fender can be suppressed. 
     In a preferred embodiment of the present invention, the fender and cover overlap portions preferably cooperate with each other to form a gripping portion extending in a direction widthwise of the motorcycle, and, in this case the gripping portion is gripped when a motorcycle rear portion or substructure is to be uplifted. According to this structural feature, since the gripping portion is formed by both of the fender and cover overlap portions, the rigidity becomes high. Therefore, a manner of uplifting the motorcycle rear portion with a hand gripping the gripping portion can be facilitated. 
     Where the fender overlap portion and the cover overlap portion extend in a direction widthwise of the motorcycle, the fender overlap portion preferably has an undersurface formed with a projection that serves as the engagement portion, in which case the cover overlap portion is provided with an engagement hole in which the projection is inserted. According to this structural feature, with a simplified structure, the engagement portion and the to-be-engaged portion can be constructed. Also, the engagement portion, which is in the form of the projection, participates in increasing the rigidity of the fender overlap portion. 
     In another preferred embodiment of the present invention, the fender and cover overlap portions preferably extend diagonally upwardly towards the outside in a direction widthwise of the motorcycle. According to this structural feature, when the rear portion of the motorcycle is to be uplifted with one hand holding a handlebar on one side of the motorcycle and with the other hand gripping the gripping portion on the other side, a force of the hand acting in a diagonally upwardly and inwardly relative to the gripping portion is applied to the gripping portion in a right angle and, therefore, the uplifting of the motorcycle rear portion can be easily accomplished. 
     In a further preferred embodiment of the present invention, the side cover is preferred connected with the motorcycle frame structure by means of a fastening member at a location forwardly thereof remote from the cover overlap portion. According to this structural feature, the side cover can be stably supported with a fastening portion and an engagement portion. 
     Any combination of at least two constructions, disclosed in the appended claims and/or the specification and/or the accompanying drawings should be construed as included within the scope of the present invention. In particular, any combination of two or more of the appended claims should be equally construed as included within the scope of the present invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In any event, the present invention will become more clearly understood from the following description of preferred embodiments thereof, when taken in conjunction with the accompanying drawings. However, the embodiments and the drawings are given only for the purpose of illustration and explanation, and are not to be taken as limiting the scope of the present invention in any way whatsoever, which scope is to be determined by the appended claims. In the accompanying drawings, like reference numerals are used to denote like parts throughout the several views, and: 
         FIG. 1  is a side view of a motorcycle embodying the present invention; 
         FIG. 2  is a fragmentary side view showing, on an enlarged scale, a rear frame assembly of the motorcycle with side covers removed; 
         FIG. 3  is a fragmentary side view showing, on an enlarged scale, a portion of a rear frame assembly of the motorcycle; 
         FIG. 4  is a side view showing a rear fender and one of the side covers separated from the rear fender; 
         FIG. 5  is a perspective view showing a rear portion of the motorcycle with the side covers removed therefrom, as viewed from diagonally upwardly and laterally; 
         FIG. 6  is a side view showing a rear end portion of the motorcycle on an enlarged scale; 
         FIG. 7  is a fragmentary longitudinal sectional view showing an engagement between the rear fender and one of the side covers; and 
         FIG. 8  is a fragmentary longitudinal sectional view showing a connection between one of the side cover and the rear frame assembly of the motorcycle. 
     
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
     A preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings. It is, however, to be noted that the terms “left” and “right” used hereinabove and hereinafter are relative terms to denote opposite positions or directions, respectively, as viewed by a motorcycle rider or motorist then occupying a motorcycle rider&#39;s seat and looking forwards in a direction parallel to the longitudinal sense of the motorcycle.  FIG. 1  is a side view of the motorcycle embodying the present invention. The motorcycle according to this embodiment is of a type suited not only for travel in the public thoroughfare, but also for off-road driving such as, for example, driving on irregular grounds including a mountain track, an irregular ground and a racing circuit. 
     The illustrated motorcycle has a motorcycle frame structure FR made up of a main frame substructure  1  to form a front frame assembly and a rear frame substructure  2  connected with the main frame substructure  1  so as to form a rear frame assembly. The main frame substructure  1  includes an upper main frame  1   a , extending diagonally downwardly and rearwardly above a motorcycle combustion engine E, and a lower main frame  1   b  which extends forwardly of the combustion engine E in a direction downwardly thereof and then extends rearwardly below the combustion engine E so that it is rigidly connected with a rear end of the upper main frame  1   a . The rear frame substructure  2  includes a pair of left and right seat rails  3 , extending from an longitudinal intermediate portion of the upper main frame  1  a in a direction rearwardly of the motorcycle, and a pair of left and right reinforcement members  4 , which extend diagonally upwardly and rearwardly from a rear end portion of the upper main frame  1   a  and are then rigidly connected with respective rear ends of the seat rails  3 . 
     A head pipe  5  is fitted to a front end portion of the main frame substructure  1 , and an upper bracket  6  and an under bracket  8  are supported by the head tube  5  through a pivotally supported steering shaft (not shown). A front fork assembly  10  has its upper portion supported by the upper bracket  6  and the under bracket  8 . 
     A front wheel  12  is rotatably supported by a lower portion of the front fork assembly  10  and a front fender  14  is fitted above the front wheel  12 . A number plate  15  such as, for example, a motorcycle racer&#39;s number plate is fitted forwardly of the front fork assembly  10  and above the front fender  14 . A steering handlebar  16  is fitted to the upper bracket  6  fast with the upper end portion of the front fork assembly  10 . 
     A swingarm bracket  18  is provided at a rear end portion of the upper main frame  1   a , and a swingarm  20  is supported by this swingarm bracket  18  through a pivot pin  23 , which is inserted in a front end portion of the swingarm bracket  18 , for movement up and down about such pivot pin  23 . A rear wheel  22  is supported by a rear end portion of the swingarm  20 . The combustion engine E referred to above is disposed intermediate between the upper main frame  1   a  and the lower main frame  1   b , and this combustion engine E drives the rear wheel  22  through a drive transmission mechanism  24  such as, for example, a substantially endless chain. An exhaust pipe  26  connected with the combustion engine E is fluid connected with a muffler  28  disposed at a left upper position of the rear wheel  22 . 
     A rider&#39;s seat  30  is supported by the rear frame substructure  2 . A rear fender  32  made of a resinous material is fitted to the rear frame substructure  2  so as to occupy a position above the rear wheel  22  where it overhangs the rear wheel  22 . The rear fender  32  is disposed rearwardly of the rider&#39;s seat  30  so as to overhang a region of the rear wheel  22  ranging from an area immediately above the rear wheel  22  to an upper area above a rear portion of the rear wheel  22 . An air cleaner unit  31  for purifying an air to be supplied to the combustion engine E is supported by the rear frame substructure  2  so as to occupy a position below the rider&#39;s seat  30  and rearwardly of the combustion engine E. The air cleaner unit  31  is made of a resinous material and has a rear end which is, as shown in  FIG. 2 , held in contact with a front end of the rear fender  32 . 
     Left and right side covers  34 , each employed for one side of the motorcycle frame structure FR and made of a resinous material, are disposed below the rider&#39;s seat  30  and forwardly of the rear fender  32  so as to conceal the rear frame substructure  2 , the air cleaner unit  31  and a portion of the muffler  28  from the outside. 
     A fuel tank  35  is fitted above the upper main frame  1   a , that is, in an upper region of the motorcycle frame structure FR and between the handlebar  16  and the rider&#39;s seat  30 . A shroud  36  extending from a region rearwardly of the head pipe  5  to a region below a front portion of the rider&#39;s seat  30  is fitted to the motorcycle frame structure FR, and the fuel tank  35  referred to above is covered by an upper portion of the shroud  36 . This shroud  36  has a rear end continued to the side cover  34 . 
       FIG. 2  illustrates a fragmentary side view showing the rear portion of the motorcycle with the side cover  34  removed away. As shown therein, left and right mounting plates  40 L and  40 R are rigidly secured to a rear end of the rear frame substructure  2  by means of welding. A rear portion of the rider&#39;s seat  30 , a front portion of the rear fender  32  and rear portions of the side covers  34  (best shown in  FIG. 1 ) are fitted to the left and right mounting plates  40 L and  40 R and, also, the muffler  28  referred to previously is fitted to the left mounting plate  40 L. 
     As shown in  FIG. 3 , the left mounting plate  40 L has a side cover mounting hole  42  and a rear fender mounting hole  44 , both of which are juxtaposed relative to each other in the longitudinal direction of the motorcycle so as to open in a direction widthwise of the motorcycle. At a position of a motorcycle widthwise inner surface of the left mounting plate  40 L, which corresponds to the side cover mounting hole  42 , a welded nut  43  is fixed. 
     A muffler mounting member  50  in the form of a collared tubular member extending in a direction widthwise of the motorcycle is fitted by welding to a lower portion of the left mounting plate  40 L, and a center hole of the muffler mounting member  50  forms a muffler mounting threaded hole  50   a . The right mounting plate  40 R is of a structure similar to the left mounting plate  40 L, but differs therefrom in that no muffler mounting member  50  is employed in this right mounting plate  40 R. 
     Referring to  FIG. 4 , the rear fender  32  has left and right first insertion holes  52  defined in respective front portions thereof so as to be oriented in a direction widthwise of the motorcycle and, also, two second insertion holes  54  defined in a widthwise juxtaposition in respective front end portions thereof so as to be oriented in a direction lengthwise of the motorcycle. A fender overlap portion  56  is formed in a lower portion of an outer side of the rear fender  32 . 
     As shown in  FIG. 5 , the fender overlap portion  56  extends diagonally upwardly from a lower end of the outer side of the rear fender  32  towards the outside in the widthwise direction of the motorcycle. A projection  58  protruding downwardly is provided in a lower surface of a rear portion of the fender overlap portion  56 . The first and second insertion holes  52  and  54  referred to above are provided forwardly of the projection  58 . 
       FIG. 4  shows the left side cover  34 . Since the left and right side covers  34  are identical in structure with each other, only one of those side covers, for example, the left side cover  34  will be referred to in the following description. The side cover  34  has a rear portion formed with the cover overlap portion  60  that is overlapped with the fender overlap portion  56  of the rear fender  32 , and this cover overlap portion  60  is provided with a groove shaped engagement hole  62  into which the projection  58  of the rear fender  32  is inserted. The cover overlap portion  60  is parallel to the fender overlap portion  56  of the rear fender  32  and extends diagonally downwardly from a lower end of the rear portion of the side cover  34  towards the inside in the widthwise direction of the motorcycle. 
     As best shown in  FIG. 7 , the cover overlap portion  60  of each of the side covers  34  is overlapped on a lower side of the fender overlap portion  56 . The fender and cover overlap portions  56  and  60  cooperate with each other to define a gripping portion  69  at the time the rear portion of the motorcycle is uplifted. The angle of inclination α of the fender and cover overlap portions  56  and  60  in a transverse section is within the range of about 15 to 25°, for example, about 20° in the instance as shown, relative to a horizontal plane H in a deadhead condition. Also, the angle of inclination β of a rear kickup of the fender overlap portion  56  and the cover overlap portion  60  shown in  FIG. 1  is within the range of 15 to 30°, for example, about 23° in the instance as shown, relative to the horizontal plane H in a deadhead condition. The fender overlap portion  56  and the cover overlap portion  60  may extend straight in the transverse section but may not be absolutely straight when viewed from side and, rather, they may be curved so as to protrude somewhat upwardly to depict a convex curve. 
     As best shown in  FIG. 6 , in an assembled condition, the projection  58  of the rear fender  32  is engaged in the engagement hole  62  of the side cover  34  to thereby regulate the position of the side cover  34  with respect to a leftward and rightward direction, that is, to prevent the side cover  34  from displacing in a transverse direction of the side cover  34 . In other words, the projection  58  forms an engagement portion for regulating the position with respect to the leftward and rightward direction whereas the engagement hole  62  forms a to-be-engaged portion. The position of the side cover  34  with respect to an anteroposterior direction is regulated by a bolt  82  which forms a fastening member as will be described later. 
     At a position forwardly of the engagement hole  62  in the rear portion of the side cover  34  shown in  FIG. 4 , a third insertion hole  64  oriented in a direction widthwise of the motorcycle is formed. Also, at an upper end of a front portion of the side cover  34 , a plug-in piece  66  is formed, and, in a lower area of the front portion of the side cover  34 , a fourth insertion hole  68  oriented in a direction widthwise of the motorcycle is formed. 
     The manner of fitting the rear fender  32  and the side cover  34  to the motorcycle frame structure FR will now be described. At the outset, the rear fender  32  shown in  FIG. 5  is fitted. By inserting a bolt  70  from rear into the second insertion hole  54  (best shown in  FIG. 4 ) in the front end of the rear fender  32  and fastening into an insert nut  72  which has been formed in a rear end of the air cleaner unit  31 , which is supported by the rear frame substructure  2 , by means of an insert molding technique, the front end of the rear fender  32  is supported by the rear frame substructure  2  through the air cleaner unit  31 . 
     Subsequently, a bolt  74 , which is a fastening member, is inserted from the outside in the motorcycle widthwise direction sequentially into the rear fender mounting holes  44  in the mounting plates  40 L and  40 R and then into the first insertion hole  52  (best shown in  FIG. 4 ) of the front portion of the rear fender  32 , and is threaded into a nut (not shown) at a location inwardly of the rear fender  32  to thereby allow the front portion of the rear fender  32  to be supported by the rear frame substructure  2 . 
     Before the side cover  34  is fitted, the muffler  28  is fitted to the left mounting plate  40 L. Specifically, a bolt  78  is inserted from an outer lateral side into a bolt insertion hole  76   a  (best shown in  FIG. 2 ) in a muffler bracket  76 , which has been fixed to an upper portion of the muffler  28 , and is subsequently threaded into the muffler mounting threaded hole  50   a  (best shown in  FIG. 3 ) in the muffler mounting member  50  of the mounting plate  40 L to allow the muffler  28  to be supported by the rear frame substructure  2  through the mounting plate  40 L. 
     Thereafter, the side cover  34  is fitted. At the outset, an upper surface of the cover overlap portion  60  of the side cover  34  is overlapped on an undersurface of the fender overlap portion  56  of the rear fender  32  shown in  FIG. 7 , followed by an engagement of the projection  58  of the rear fender  32  into the engagement hole  62  in the side cover  34 . 
     Also, the side cover  34  is fitted to the rear frame substructure  2  by means of bolts  82  and  86  shown in  FIG. 1 . The rear portion of the side cover  34  is, as shown in  FIG. 8 , fitted to the mounting plate  40 L together with the rider&#39;s seat  30 . Specifically, the bolt  82  is inserted from the outside in the motorcycle widthwise direction through the third insertion hole  64  in the side cover  34  and then through the bolt insertion hole  80   a  in a seat bracket  80 , provided in the rider&#39;s seat  30 , and is threaded into the welded nut  43  in the side cover mounting hole  42  of the mounting plate  40 L of the rear frame substructure  2 , thus allowing the rear portion of the side cover  34  and the rear portion of the rider&#39;s seat  30  to be supported by the rear frame substructure  2 . A front portion and a longitudinal intermediate portion of the rider&#39;s seat  30  are supported by the rear frame substructure  2  by means of separate means. 
     The upper portion of the front portion of the side cover  34  shown in  FIG. 1  is fitted to the shroud  36  when the inserting piece  66  (best shown in  FIG. 4 ) is inserted into a to-be-inserted portion (not shown) of a rear portion of the shroud  36 . A lower portion of the front portion of the side cover  34  is fitted to a lower portion covering mounting bracket  90  (best shown in  FIG. 2 ) of the rear frame substructure  2  by means of a bolt  86 . More specifically, the bolt  86  is inserted into the fourth insertion hole  68  (best shown in  FIG. 4 ) of the side cover  34  from the outside and is fastened to a threaded hole  90   a  (shown in  FIG. 2 ) defined in the lower portion covering mounting bracket  90 . 
     In the construction described above, as shown in  FIG. 6 , since the front portion of the rear fender  32  and the rear portion of the side cover  34  are engaged with each other, opening of the rear portion of the side cover  34  in leftward and rightward directions is suppressed with no gap formed between the rear fender  32  and the side cover  34 . Also, since the rear portion of the side cover  34  is merely engaged in the front portion of the rear fender  32 , the rear fender  32  need not be extended forwardly, be overlapped with the side cover  34  and be bolted to the side cover  34 , and, hence, an increase in size of the rear fender  32  can also be avoided. 
     In the case of the motorcycle shown in  FIG. 1 , which is specifically designed for driving in a racing circuit, in a condition with the handlebar  16  on one side of the motorcycle gripped by a hand and with the other hand gripping the gripping portion  69  on the other side, the rear portion of the motorcycle is uplifted to allow the lower main frame  1   b  to be mounted on a maintenance stand  100  provided separately. In the illustrated embodiment, since the gripping portion  69  extends in the motorcycle widthwise direction, it is easy for the hand to be used in uplifting the rear portion of the motorcycle, and also since the rear fender  32  and the side cover  34  are overlapped, the gripping portion  69  has a high strength. In this instance, the gripping portion  69  is diagonally upwardly inclined at the angle of inclination α towards the outside and is also, as shown in  FIG. 1 , inclined diagonally upwardly at the angle of inclination β towards the rear. Therefore, the force of the hand is efficiently applied to the gripping portion  69  in a right angled direction, that is, in a direction diagonally upwardly and forwardly and towards the motorcycle inner side (shown in  FIG. 7 ), and as a result, the uplifting of the motorcycle rear portion become easy to achieve. 
     As shown in  FIG. 7 , the projection  58  protruding downwardly is provided in the undersurface of the fender overlapping portion  56  and the engagement hole  62 , which is oriented in a vertical direction, is provided in the cover overlap portion  60  comprised of a flat surface. Therefore, the engagement and the to-be-engaged portion can be realized with a simplified structure. Also, the engagement portion comprised of the projection  58  improves the rigidity of the fender overlap portion  56 . 
     As shown in  FIG. 6 , since the side cover  34  is connected with the rear frame substructure  2  (shown in  FIG. 1 ) by means of the bolt  82  at a site forwardly of the cover overlap portion  60 , a bolt fastening portion and an engagement portion cooperate with each other to stably support the rear portion of the side cover  34 . 
     Although the present invention has been fully described in connection with the preferred embodiments thereof with reference to the accompanying drawings which are used only for the purpose of illustration, those skilled in the art will readily conceive numerous changes and modifications within the framework of obviousness upon the reading of the specification herein presented of the present invention. By way of example, although in describing the preferred embodiment, reference has been made to the racing motorcycle that is driven in the racing circuit, the present invention can be applied to any motorcycle in general. 
     Also, although in the previously described embodiment, the projection (engagement portion)  58  has been shown and described as formed in the fender overlap portion  56  and the engagement hole (to-be-engaged portion)  62  has been shown and described as formed in the cover overlap portion  60 , the engagement hole and the projection may be formed in the fender overlap portion  56  and the cover overlap portion  60 , respectively. 
     Accordingly, such changes and modifications are, unless they depart from the scope of the present invention as delivered from the claims annexed hereto, to be construed as included therein. 
     REFERENCE NUMERALS 
       2 : Rear frame substructure (Motorcycle frame structure) 
       22 : Rear wheel 
       30 : Rider&#39;s seat 
       32 : Rear fender 
       34 : Side cover 
       56 : Fender overlap portion 
       58 : Projection (Engagement portion) 
       60 : Cover overlap portion 
       62 : Engagement hole (To-be-engaged portion) 
       69 : Gripping portion