Abstract:
A motorcycle saddlebag mounting device having a restricting means for staggering timings of yawing occurring in a motorcycle body and resonance caused by lateral swing of a saddlebag is provided. The restricting means is provided between a support bracket mounted to a seat rail and a saddlebag mounting frame rotatably mounted to the support bracket. Rotation of the frame with respect to the support bracket is restricted, so that resonance caused by yawing of the motorcycle body and lateral swing of the saddlebag is cancelled out.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention relates to a motorcycle saddlebag mounting device for mounting a saddlebag to a motorcycle body.  
         BACKGROUND OF THE INVENTION  
         [0002]    As this kind of saddlebag mounting device, a motorcycle saddlebag mounting device disclosed, for example, in Japanese Utility Model Laid-Open Publication No. HEI-3-3117 is known. This conventional saddlebag mounting device will be described with reference to FIG. 11.  
           [0003]    Referring to FIG. 11, a saddlebag mounting device  100  has a step holder  102  and a side grip  103  mounted to a body frame  101 . A support stay  104  is mounted between the step holder  102  and the side grip  103 . A support shaft  105  inclined with respect to a vertical direction of the body is rotatably provided between the step holder  102  and the support stay  104 , mounted swingably about a pin  105   a  with respect to the support stay  104 . A frame  106  to which a saddlebag  108  is mounted is fixed at both its ends to the shaft  105 . An elastic member  107  is interposed between the support stay  104  and the frame  106 . The elastic member  107  damps rotation of the frame  106  accompanying rotation of the support shaft  105 .  
           [0004]    Mounting the saddlebag  108  to the body and putting a heavy load in the saddlebag  108  increases oscillations of the motorcycle body in high-speed driving. One of the motorcycle body oscillations is a yawing resonance frequency.  
           [0005]    Since the support stay  104  is supported by the step holder  102  and the side grip  103  in the saddlebag mounting device  100 , it is difficult to change the yawing resonance frequency of the body frame  101 . Thus, when mounting the motorcycle saddlebag mounting device  100  to the body frame  101 , it is also required to consider the yawing resonance frequency to reduce the occurrence of yawing.  
           [0006]    Further, since the support stay  104  is supported between the step holder  102  and the side grip  103  in the above-described structure, variations in mounting dimensions of the support stay  104  are likely to occur.  
           [0007]    It is thus desired to be able to mount the support stay  104  or the like to the motorcycle body with high precision and to reduce the occurrence of yawing.  
         SUMMARY OF THE INVENTION  
         [0008]    According to the present invention, there is provided a motorcycle saddlebag mounting device for mounting a saddlebag to a seat rail extending rearward from a rear end of a main frame, which device comprises: a support bracket mounted to the seat rail along an outside surface of the seat rail; a support shaft mounted to the support bracket; a saddlebag mounting frame rotatably mounted at one side thereof to the support shaft; and a restricting means for restricting rotation of the frame about the support shaft.  
           [0009]    The restricting means has the function of staggering timing in which yawing occurs in the motorcycle body and timing in which lateral swing resonance of the saddlebag occurs. The provision of the restricting means for restricting rotation of the frame with respect to the support shaft of the support bracket thus allows resonance due to yawing of the motorcycle body and lateral swing of the saddlebag to be cancelled out.  
           [0010]    Since the support bracket is mounted along the outside surface of the seat rail, the yawing resonance frequency of the main frame can be varied through the seat rail. Further, the yawing resonance frequency of the seat rail can be directly varied. As a result, the occurrence of yawing can be reduced. That is, with the mounting portion of the swingable saddlebag to the motorcycle body positioned sidewardly of the seat rail via the support bracket, a yaw moment to be generated by swinging movement of the saddlebag at the seat rail, a source of its generation, can be significantly reduced or dampened.  
           [0011]    In a preferred form, the support shaft is provided at a longitudinally substantially middle portion of the seat rail in such a manner as to intersect the seat rail in a side view. At the middle portion of the seat rail, moment in a yaw direction is likely to occur in high-speed driving. Therefore, the center of swing of the saddlebag is positioned at the middle portion so as to disperse a yawing moment, efficiently damping yawing, and stabilizing the motorcycle body.  
           [0012]    Preferably, the restricting means is provided between the support bracket and the frame, including elastic members for damping swing of the frame about the support shaft. As a result, movement of the frame can be softened and yawing of the main frame or the seat rail can be converged. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]    Preferred embodiments of the present invention will be described in detail below, by way of example only, with reference to the accompanying drawings, in which:  
         [0014]    [0014]FIG. 1 is a side view of a motorcycle equipped with a saddlebag mounting device according to the present invention;  
         [0015]    [0015]FIG. 2 is a plan view of the motorcycle shown in FIG. 1;  
         [0016]    [0016]FIG. 3 is a side view of the saddlebag mounting device according to the invention;  
         [0017]    [0017]FIG. 4 is a top view of the saddlebag mounting device shown in FIG. 3;  
         [0018]    [0018]FIG. 5 is a cross-sectional view taken along line  5 - 5  in FIG. 3;  
         [0019]    [0019]FIG. 6 is an exploded perspective view of the saddlebag mounting device according to the invention;  
         [0020]    [0020]FIG. 7 is a cross-sectional view of a restricting means interposed between a support bracket and a frame;  
         [0021]    [0021]FIG. 8 is a plan view of a first elastic member shown in FIG. 7;  
         [0022]    [0022]FIG. 9 is a cross-sectional view taken along line  9 - 9  in FIG. 8;  
         [0023]    [0023]FIGS. 10A to  10 C are diagrams illustrating the damping of rotation of a saddlebag by the restricting means; and  
         [0024]    [0024]FIG. 11 is a side view of a conventional saddlebag mounting device. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0025]    Referring to FIGS. 1 and 2, a motorcycle  10  has a body frame  11 . A head tube  12  is provided at the front of the body frame  11 . Left and right front fork parts  13 ,  13  are mounted to the head tube  12  in a steerable manner. A steering handle  15  is mounted on a top bridge  14  of the front fork parts  13 ,  13 . A headlight  18  and left and right front winkers  19 ,  19  are positioned forward of and between the top bridge  14  and a bottom bridge  16 . A front fender  22  and a front wheel  23  are mounted to a lower portion of the front fork  13 .  
         [0026]    A main frame  24  extends rearward from the front end of the body frame  11 . A down tube  25  extends downward from the front end of the body frame  11  and also extends horizontally rearward of the motorcycle body. An engine  26  is disposed between the main frame  24  and the down tube  25 . A fuel tank  29  is provided on the main frame  24 .  
         [0027]    A seat rail  28  extends rearwardly from the rear end of the main frame  24  and the rear end of a subframe  32  to be discussed below. A seat (tandem seat)  31  is mounted onto the seat rail  28 .  
         [0028]    The subframe part  32  is interposed between the rear end of the down tube  25  and the front end of the seat rail  28 . The front end of the seat rail  28  connected to the rear end of the subframe  32  by, e.g., welding. A rear swing arm  34  is mounted at its front end on a pivot  33  provided at a vertically substantially middle portion of the subframe part  32 , and extends at its rear end rearward. A rear wheel  35  is rotatably mounted to the rear end of the rear swing arm  34 . A rear cushion  36  is provided between a rear portion of the rear swing arm  34  and the body frame  11 . Reference numerals  38 ,  39  denote exhaust pipes extending from the engine  26 .  
         [0029]    The two exhaust pipes  38 ,  39  are connected to a collecting pipe  41  as shown in FIG. 2. A muffler  42  is connected to the distal end of the collecting pipe  41 . In the figure, reference numeral  43  denotes a rear fender,  44  a license lamp,  45 ,  45  rear winkers, and  46  a taillight.  
         [0030]    The tandem seat  31  includes a driver&#39;s seat  47  to be occupied by a driver and a passenger&#39;s seat  48  to be occupied by a passenger. The passenger&#39;s seat  48  is positioned rearward of the driver&#39;s seat  47  and higher than the driver&#39;s seat  47 .  
         [0031]    The motorcycle  10  has left and right saddlebag mounting devices  50 ,  51  according to the present invention for mounting left and right saddlebags  52 ,  53  to the rear opposite sides thereof.  
         [0032]    The left and right saddlebag mounting devices  50 ,  51  are positioned symmetrically with respect to the centerline C of the motorcycle body. The left and right saddlebag devices  50 ,  51  have the same configuration and the left and right saddlebags  52 ,  53  also have the same configuration. Hereinafter, description will thus be made on the left saddlebag device  50  and the left saddlebag  52 , and no description will be made on the right saddlebag device  51  and the right saddlebag  53 .  
         [0033]    As shown in FIGS. 3 and 4, the left saddlebag mounting device (hereinafter only referred to as a saddlebag device)  50  has a support bracket  55  for rotatably supporting a frame  57 , a support shaft  56  provided at the support bracket  55 , rotatably supporting the frame  57 , the frame  57  to which the saddlebag  52  is mounted, and a restricting means  58  for restricting rotation of the frame  57  with respect to the support bracket  55 .  
         [0034]    The support bracket  55  is mounted to an outside surface of the seat rail  28  extending rearward from the rear end of the main frame  24 .  
         [0035]    The support shaft  56  is a bolt mounted to the bracket  55  in such a manner as to be located at a substantially middle portion of the seat rail  28  and intersect the seat rail  28  in a side view. Reference numeral  75  denotes a nut for the support shaft  56 .  
         [0036]    As shown in FIG. 5, the support bracket  55  is mounted with a bolt  61  to the seat rail  28  located on an outside surface of the rear fender  43  via a spacer  62  and a grab rail  54 . The rear fender  43  is mounted with the bolt  61  to the seat rail  28  with a fender bracket  63  located inside the rear fender  43 . That is, the bracket  55 , spacer  62  and grab rail  54  located outside the rear fender  43 , and the rear fender  43  and the fender bracket  63  located inside thereof are fastened together to the seat rail  28  with the bolt  61  and a nut  64 .  
         [0037]    As shown in FIG. 6, the saddlebag  52  consists of a bag body  65  to hold hand luggage and a lid  66  attached to the bag body  65  in an openable and closable manner.  
         [0038]    The bag body  65  has a plurality of mounting holes  67  (four in the illustrated example), and is fixed to the frame  57  with mounting screws  69  via collars  68  inserted into the mounting holes  67 .  
         [0039]    The support bracket  55  consists of a base plate  70   a  and side walls  70   b ,  70   b  integrally provided at the opposite sides thereof, having a channel section shape.  
         [0040]    The side walls  70   b ,  70   b  are formed with shaft insertion holes  71 ,  71 , respectively, through which the support shaft  56  of a bolt is inserted. The base plate  70   a  has a mounting hole  72  for mounting components of the restricting means  58  shown in FIG. 6, and two through holes  73 ,  73  through which the bolts  61 ,  61  shown in FIG. 4 extend.  
         [0041]    The support bracket  55  is mounted with a hanger  74  on which a helmet not shown is hung.  
         [0042]    The frame  57  has a pipe section frame  76 , a connecting pipe  77  attached to the frame  76  to allow insertion of the support shaft  56  therethrough in such a manner as to be rotatable with respect to the support shaft  56 , two reinforcing plates  78 ,  78  for reinforcing the mounting of the connecting pipe  77  to the pipe frame  76 , a mounting plate  79  mounted in such a manner as to protrude toward a closed plane of the pipe frame  76  for mounting the restricting means  58  shown in FIG. 7 thereto, and mounting portions  81 ,  82  provided around the periphery of the pipe frame  76  for mounting the saddlebag  52  thereto.  
         [0043]    The mounting plate  79  has a restricting means mounting hole  83  formed for mounting the restricting means  58  thereto.  
         [0044]    Since mounting portions of the swingable saddlebag  52  to the motorcycle body are thus concentrated on the outside surface of the seat rail  28 , a yaw moment generated from the seat rail  28  by swing motion of the saddlebag  52  can be effectively reduced from a source of its generation.  
         [0045]    The frame  57  to which the saddlebag  52  is mounted is mounted to the bracket  55  via the support shaft  56 , and the restricting means  58  is also mounted to the bracket  55 . When mounting the saddlebag mounting device  50  to the motorcycle body, it is only required to mount the bracket  55  to the seat rail  28  of the body, resulting in facilitated mounting and increased precision in mounting the saddlebag mounting device  50  to the motorcycle body.  
         [0046]    In the conventional saddlebag mounting device shown in FIG. 11, for example, in which the support shaft  105  is arranged at an inclination with respect to a vertical line, the saddlebag  108  also moves in a vertical direction when the frame  106  to which the saddlebag  108  is mounted swings with the support shaft  105 .  
         [0047]    In this embodiment, the support shaft  56  is slightly inclined to be in as nearly a vertical position as possible, thereby to minimize the vertical movement of the saddlebag  52  accordingly. As a result, vibration of luggage held in the saddlebag  52  is minimized to reduce a pitching motion of the motorcycle body. Further, rolling, a rotary motion of the motorcycle body about the center of gravity, is also minimized.  
         [0048]    The restricting means  58  includes, as shown in FIG. 7, a first elastic member  86  disposed outside the mounting plate  79 , a second elastic member  87  disposed inside the mounting plate  79 , washers  88 ,  89  put on the first and second elastic members  86 ,  87 , respectively, a collar  91  extending through the mounting plate  79  and the first and second elastic members  86 ,  87 , a bolt  92  extending through the collar  91 , the washers  88 ,  89  and the support bracket  55 , and a nut  93  screwed onto the bolt  92 .  
         [0049]    The first and second elastic members  86 ,  87  are the same, and the washers  88 ,  89  are also the same.  
         [0050]    The collar  91  is a distance limiting member for producing a predetermined initial deformation in the first and second elastic members  86 ,  87 . Specifically, the collar  91  is a member for ensuring a predetermined dimension A of the first and second elastic members  86 ,  87  when the mounting plate  79  is sandwiched between the first and second elastic members  86 ,  87  and the first and second elastic members  86 ,  87  and the mounting plate  79  are fastened to the bracket  55  with the bolt  92 . Thus, the collar  91  can produce the predetermined initial deformation in the first and second elastic members  86 ,  87  with high precision.  
         [0051]    Consequently, the frame  57  can be swung as shown by arrows B, B, and also the swing of the frame  57  can be damped.  
         [0052]    [0052]FIGS. 8 and 9 illustrate the first elastic member  86  of the restricting means  58  shown in FIG. 7.  
         [0053]    The first elastic member  86  consists of a body  94 , a collar through hole  95  formed in the center of the body  94 , and a plurality of slits  96  formed in one end of the body  94  for previously causing the predetermined initial deformation.  
         [0054]    The provision of the slits  96  in the first elastic member  86  can facilitate the production of the predetermined initial deformation.  
         [0055]    Now, the function of the saddlebag mounting device  50  will be described with reference to FIGS. 10A to  10 C.  
         [0056]    [0056]FIG. 10A illustrates the saddlebag mounting device  50  and the saddlebag  52  when the motorcycle  10  shown in FIG. 2 is going straight. At that time, the first and second elastic members  86 ,  87  maintain the predetermined initial deformation.  
         [0057]    [0057]FIG. 10B illustrates the saddlebag mounting device  50  and the saddlebag  52  when the motorcycle  10  is turned left. When the motorcycle  10  is turned left as shown by arrow b 1 , the frame  57  tilts toward the center of the body as shown by arrow b 2  about the support shaft  56 . At that time, the first elastic member  86  expands and the second elastic member  87  receives a force in a compression direction.  
         [0058]    [0058]FIG. 10C illustrates the saddlebag mounting device  50  and the saddlebag  52  when the motorcycle  10  is turned right. When the motorcycle  10  is turned right as shown by arrow c 1 , the frame  57  tilts toward the outside of the body as shown by arrow c 2  about the support shaft  56 . At that time, the second elastic member  87  expands, and the first elastic member  86  receives a force in a compression direction.  
         [0059]    In summary, the restricting means  58  has the first and second elastic members  86 ,  87  interposed between the frame  57  and the support bracket  55  so as to damp the swing of the frame  57  about the support shaft  56 . Therefore, the swing motion of the frame  57  is reduced. As a result, yawing of the main frame  24  (see FIG. 3) or the seat rail  28  can be converged.  
         [0060]    The embodiment has been illustrated with the example of forming the slits  96  in the elastic member  86  as shown in FIG. 9, but is not limited thereto. Alternatively, an elastic member of a substantially cylindrical member without slits may be used.  
         [0061]    Obviously, various minor changes and modifications of the present invention are possible in the light of the above teaching. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.