Abstract:
A motorcycle includes a front part having a steering mechanism with which a front wheel is steered based on the manipulation of the steering of a steering handle, and a swing mechanism extending from either a body frame and an engine for vertically movably supporting the steering mechanism. The steering mechanism is connected to the swing mechanism via a lower spherical bearing and an upper spherical bearing.

Description:
FIELD OF THE INVENTION 
     The present invention relates to a motorcycle including a steering mechanism for steering a front wheel and a swinging mechanism extending from a body frame or an engine, for vertically movably supporting the steering mechanism. 
     BACKGROUND OF THE INVENTION 
     A motorcycle in which a front wheel is attached by a swing arm to a body frame is disclosed in JP 2002-500133 A. Main portions of the motorcycle will be described below with reference to  FIGS. 19 and 20  hereof. 
     As shown in  FIG. 19 , in the motorcycle  200 , a lower swing arm  203  and a middle swing arm  204  extend frontward from a body frame  201  or an engine  202 . A distal end of the lower swing arm  203  and a distal end of the middle swing arm  204  are connected by V-shaped plates  205 . 
     A steering handle  208  is fitted in a head pipe  207  that is provided at a front part of the body frame  201 . A handle link  209  that is capable of vertically bending is connected to a lower end of the steering handle  208 . A knuckle arm  210  is connected to a lower end of the handle link  209 . The knuckle arm  210  is a member for directly steering (pivoting) a front wheel  211 . 
     An upper swing arm  212  extends frontward from the body frame  201 , and an upper part of the knuckle arm  210  is connected to a distal end of the upper swing arm  212 . 
     As shown in  FIG. 20 , the front wheel  211  comprises a tire  214 ; a rim  215  for directly supporting the tire  214 ; spokes  216  extending from the rim  215 ; and a hub  217  connected to the spokes  216 . 
     A hub body  219  is accommodated within the hub  217  via an axle bearing  218  so as to be capable of relative rotation. A pivot pin  221  extending from an axle  220  is fitted into the hub body  219 . A lower end of the knuckle arm  210  is connected to the hub body  219 . 
     A spline  222  is formed in an end part of the axle  220 . A coupling  223  is fitted onto the spline  222  and secured to the V-shaped plates  205 . The distal end of the upper swing arm  212  is connected to the knuckle arm  210  via a ball bearing  224 . 
     The pivot pin  221  is stationary in the Figure because the axle  220  is secured by the V-shaped plates  205 ,  205 . The hub body  219  rotates about the pivot pin  221 , whereby the front wheel  211  is steered. The front wheel  211  rotates about the pivot pin  221  and about the axle  220 . 
     In  FIG. 19 , the length of the upper swing arm  212  changes when the lower swing arm  203  and the middle swing arm  204  swing together in the vertical direction. Specifically, the distance between a pin  225  provided on the body frame  201  and the ball bearing  224  provided in the knuckle arm  210  changes. The upper swing arm  212  is connected to the pin  225  via an intermediate pin  226  and an auxiliary link  227  in order for such changes in distance to be addressed. 
     As is evident from the description above, the motorcycle  200  must be provided with the lower swing arm  203 , the middle swing arm  204 , the upper swing arm  212 , the intermediate pin  226 , and the auxiliary link  227 . Problems therefore arise in that the structure of the motorcycle  200  is complex, and costs associated with the manufacture of the motorcycle  200  are high. 
     A demand has accordingly arisen for a motorcycle having a front wheel attached to a body frame using swing arms to have a simpler structure that allows manufacturing costs to be lowered. 
     SUMMARY OF THE INVENTION 
     According to the present invention, there is proposed a motorcycle having a steering mechanism for steering a front wheel through manipulation of a steering handle, and a swing mechanism extending from one of a body frame and an engine for vertically movably supporting the steering mechanism, wherein the steering mechanism comprises: a hub body for rotatably supporting the front wheel; knuckle arms extending upwardly from the hub body; a handle link connected to an upper end of the knuckle arms and being capable of bending vertically; and the steering handle provided on an upper end of the handle link, and wherein the swing mechanism comprises lower swing arms vertically swingably connected to one of the body frame and the engine and extending to the hub body; a cross-member provided on distal ends of the lower swing arms and passing through the hub body; a lower spherical bearing provided on the cross-member for three-dimensionally rotatably supporting the hub body; upper swing arms vertically swingably connected to one of the body frame and the engine and extending to upper parts of the knuckle arms; and an upper spherical bearing provided on distal ends of the upper swing arms for three-dimensionally swingably supporting the knuckle arms. 
     The hub body is three-dimensionally rotatably supported by the lower spherical bearing on the distal end of the lower swing arm that extends from the body frame or the engine. The front wheel can therefore be steered. 
     The front wheel is steered via the steering handle, the handle link, and the knuckle arm. Among these, the knuckle arm, which is connected to the hub body, is three-dimensionally rotatably supported by the upper spherical bearing on the distal end of the upper swing arm that extends from the body frame or the engine. The knuckle arm can therefore be steered. 
     Using the lower spherical bearing and the upper spherical bearing allows merely a lower swing arm and an upper swing arm to be used. In other words, in a motorcycle in which a front wheel is attached to a body frame by a swing arm, it is possible to provide a structure in which the structure is simplified and manufacturing costs can be reduced. 
     Preferably, the ball bearing is disposed between a hub of the front wheel and the hub body. The ball bearing is disposed between the hub body, which is a non-rotating member, and the hub, which is a rotating member. Accordingly, the hub can spin smoothly, and frictional resistance can be reduced. 
     Desirably, an inside diameter of the hub body is set to be larger than an outside diameter of the cross-member. Accordingly, the cross-member can be incorporated with the hub body, and the outward appearance of the hub periphery can be improved. 
     It is desirable that the knuckle arms are detachably fastened to the hub body by a first fastening member, the lower swing arms are detachably fastened to the cross-member by a second fastening member, and the first fastening member and the second fastening member extend parallel to the cross-member. When a tire is changed, the front wheel must be removed from the lower swing arm. In this case, the first fastening member is loosened, whereby the knuckle arm is separated from the hub body. Next, the second fastening member is loosened, whereby the cross-member is separated from the lower swing arm. The front wheel can thereby be removed. 
     The first fastening member and the second fastening member extend parallel to the cross-member. The operation of loosening the first fastening member and the second fastening member can therefore be performed from the side of the vehicle body. Accordingly, the operation of removing the front wheel is greatly facilitated. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Certain 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: 
         FIG. 1  is a left side view of a motorcycle according to the present invention; 
         FIG. 2  is a front view of the motorcycle; 
         FIG. 3  is an exploded view of a front part of the motorcycle; 
         FIG. 4  is a perspective view of the front part of the motorcycle; 
         FIG. 5  is a top plan view of the front part of the motorcycle; 
         FIG. 6  is a sectional view taken along line  6 - 6  of  FIG. 5 ; 
         FIG. 7  is a sectional view taken along line  7 - 7  of  FIG. 5 ; 
         FIGS. 8A and 8B  are diagrams showing an operation of a lower spherical bearing and an upper spherical bearing; 
         FIGS. 9A and 9B  are diagrams illustrating a steering stopper; 
         FIG. 10  is an exploded view illustrating an operation of changing a tire; 
         FIGS. 11A and 11B  are schematic views showing an operation of a front cushioning unit; 
         FIG. 12  is a diagram showing a relationship between an upper swing arm and the front cushioning unit; 
         FIG. 13  is a perspective view showing a separate embodiment of the motorcycle front part shown in  FIG. 4 ; 
         FIG. 14  is a schematic view showing a separate embodiment of the motorcycle of  FIG. 1 ; 
         FIG. 15  is a perspective view showing the steering handle and parts associated therewith; 
         FIG. 16  is a sectional view taken along line  16 - 16  of  FIG. 15 ; 
         FIG. 17  is an exploded perspective view showing the steering handle and parts associated therewith; 
         FIGS. 18A ,  18 B, and  18 C are schematic views showing a mode of assemblage of the steering handle; 
         FIG. 19  is a left side view of a conventional motorcycle; and 
         FIG. 20  is a perspective view of a front wheel of the conventional motorcycle. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     An overall structure of the motorcycle will be described with reference to  FIGS. 1 and 2 . 
     As shown in  FIG. 1 , disposed in a front part  10 F of a motorcycle  10  are main frames  11   a  as constituent elements of a body frame  11 ; an upper swing arm  13 L that extends forward from an upper part of the main frames  11   a , and that is swingably supported in a vertical direction by an upper front swing shaft  12 L; a lower swing arm  15 L that extends forward from a lower part of the main frames  11   a , and that is swingably supported in a vertical direction by a lower front swing shaft  14 L so as to be capable of swinging in the vertical direction; a hub steering mechanism  20  that is provided to a distal end of the lower swing arm  15 L, and that steerably supports a front wheel  16 ; a knuckle arm  21 L that is provided above the hub steering mechanism  20 , and that steerably supports the front wheel  16 ; a handle link  22  that is attached to an upper end part of the knuckle arm  21 L, and that is capable of bending in a vertical direction; a steering handle  23  that is attached to an upper end part  22   t  of the handle link  22 , and that is steered by a rider; and a front part cushioning mechanism  25  that is provided between the upper swing arm  13 L and the main frames  11   a , and that absorbs force applied to the front wheel  16 . 
     The hub steering mechanism  20  is defined as a construction in which a mechanism that allows the wheel to pivot is provided to the wheel hub. 
     As shown in  FIG. 2 , an upper front pivot shaft  12 R is disposed so as to form a pair with the upper front swing shaft  12 L. An upper swing arm  13 R, a lower swing arm  15 R, and a knuckle arm  21 R are similarly disposed. 
     As shown in  FIG. 1 , a handle support frame  27  extends forward from an engine  26 . A head pipe  28  is attached to a front end part of the handle support frame  27 , and a steering handle  23  is rotatably attached to the head pipe  28 . 
     A handle link  22  is connected between the knuckle arm  21 L and the steering handle  23 , and the knuckle arm  21 L is capable of moving in the vertical direction. Specifically, a force applied to the knuckle arm  21 L is not directly transmitted to the steering handle  23  as a result of the handle link  22  being disposed therebetween. Accordingly, it is possible to reduce the weight of the handle support frame  27 . 
     Disposed in a rear portion  10 R of the motorcycle  10  are upper and lower arm members  33 L,  34 L that extend rearward from the main frames  11   a , and that are connected to the main frames  11   a  by upper and lower pivot shafts  31 L,  32 L so as to be capable of swinging upward and downward; an arm body  37  that extends rearward from rear end parts of the upper and lower arm members  33 L,  34 L, and that is swingably connected by rear support shafts  35 ,  36 L; a rear wheel  39  that is rotatably attached to a rear end part of the arm body  37  via a rear axle  38 ; and a rear cushioning mechanism  41  that is provided between the arm body  37  and the main frames  11   a , and that absorbs force applied to the rear wheel  39 . 
     The upper arm member  33 L extends from an upper part of a rear end part of the main frames  11   a , and the lower arm member  34 L extends from a lower part of the rear end part of the main frames  11   a.    
     The engine  26  is suspended on the main frames  11   a  as a drive source, and a driveshaft  42 , which drives the rear wheel  39 , extends from a rear end part of the engine  26 . 
     The engine  26  is provided with an air cleaner  44  as a constituent element of an intake system; and an exhaust pipe  45 , which is a constituent element of an exhaust system, and through which exhaust gas of the engine  26  passes. 
     A front disc brake  47 L is attached to the front wheel  16 . The front disc brake  47 L comprises a front wheel brake disc  48 L that is attached to the front wheel  16 ; and a front wheel disc caliper  49 L that is attached to the knuckle arm  21 L, and that clamps the front wheel brake disc  48 L during braking. 
     A rear disc brake  51  is attached to the rear wheel  39 . The rear disc brake  51  comprises a rear wheel brake disc  52  that is attached to the rear wheel  39 ; and a rear wheel disc caliper  53  that is attached to the arm body  37 , and that sandwiches the rear wheel brake disc  52  during braking. 
     Two upper and lower radiators  55 T,  55 B that are vertically disposed and that cool the engine  26  are provided between the engine  26  and the front wheel  16 . The upper radiator  55 T is disposed between the upper swing arm  13 L and the lower swing arm  15 L. The lower radiator  55 B is disposed below the lower swing arm  15 L. 
     Upper and lower ducts  56 T,  56 B for guiding suctioned air to the radiators  55 T,  55 B are provided in front of the upper and lower radiators  55 T,  55 B. The upper and lower radiators  55 T,  55 B and the upper and lower ducts  56 T,  56 B are attached to the lower swing arm  15 L. A front cowling  57  indicated by an imaginary line is disposed in front of the steering handle  23 . A fuel tank  58  is disposed rearward of the steering handle  23 . A seat  59  is disposed rearward of the fuel tank  58 . 
     Specifically, the body frame  11  and the front wheel  16  are connected by four arms, comprising the upper swing arms  13 L,  13 R (see  FIG. 2 ) and the lower swing arms  15 L,  15 R (see  FIG. 2 ). Accordingly, a space can be maintained in front of the engine  26 . Ensuring that this space is present allows the components to be disposed with a greater degree of latitude. For example, the upper and lower radiators  55 T,  55 B can be disposed in this space. The two radiators  55 T,  55 B enable adequately robust cooling performance to be demonstrated. 
     In the present embodiment, the engine  26  is a V-type engine in which cylinders are disposed in a V-shape. However, the engine  26  may also be an in-line engine in which cylinders are disposed in a row. The engine is in a so-called transverse layout in which a crankshaft is disposed in a width direction of the vehicle. However, the engine may also have a so-called vertical layout in which the crankshaft is disposed in the longitudinal direction of the vehicle. The engine is not limited to being cooled by water, and may also be cooled by air. In other words, the type and layout of the engine are not limited to the embodiments, and can be configured as required. 
     A front cushioning unit  61  for absorbing force is provided to the front cushioning mechanism  25 . The exhaust pipe  45  through which exhaust gas of the engine  26  passes is disposed externally with respect to the front cushioning unit  61 . 
     The exhaust pipe  45  through which exhaust gas of the engine  26  passes is disposed externally with respect to, or in front of, the front cushioning unit  61 . The exhaust pipe  45  also serves to protect the expensive front cushioning unit  61 . 
     The structure of the front part  10 F of the motorcycle  10  will be described in detail below with reference to the drawings. 
     As shown in  FIG. 3 , the front part  10 F of the motorcycle comprises a steering mechanism  60 A by which the front wheel  16  is steered on the basis of the operation of the steering handle  23 ; and a swing mechanism  60 B, which extends from the body frame or the engine, and which is supported on the steering mechanism  60 A so as to be capable of moving in the vertical direction. 
     The steering mechanism  60 A comprises a hub body  76  (see  FIG. 6 ) that rotatably supports the front wheel  16 ; knuckle arms  21 L,  21 R that extend upward from the hub body  76 ; the handle link  22  that is connected to upper ends of the knuckle arms  21 L,  21 R, and that is capable of bending in the vertical direction; and the steering handle  23  that is provided to an upper end of the handle link  22 . 
     The swing mechanism  60 B comprises the lower swing arms  15 L,  15 R that are connected to the body frame or the engine so as to be capable of rotating in the vertical direction, and that extend to the hub body  76  (see  FIG. 6 ); a cross-member  62  that is provided to distal ends of lower swing arms  15 L,  15 R, and that passes through the hub body  76 ; a lower spherical bearing  82  that is provided to the cross-member  62 , and that three-dimensionally and rotatably supports the hub body  76 ; the upper swing arms  13 L,  13 R that are connected to the body frame or the engine so as to be capable of rotating in the vertical direction, and that extend to an upper part of the knuckle arms  21 L,  21 R; and an upper spherical bearing  91  that is provided to distal ends of the upper swing arms  13 L,  13 R, and that three-dimensionally and rotatably supports the knuckle arms  21 L,  21 R. The cross-member  62  preferably extends across the pair of lower swing arms  15 L,  15 R, but may also extend from only the lower swing arm  15 L or only the lower swing arm  15 R. In cases where there is only one lower swing arm, the cross-member  62  extends from the one lower swing arm. 
     The handle link  22  comprises a lower link arm  64  and an upper link arm  66 , where the upper link arm  66  is connected to the lower link arm  64  by a connecting pin  65 . An upper end  22   t  is connected to the steering handle  23 , and a lower end  22   b  is connected to the knuckle arm  21 L. 
     An upper end part  69   t  of a rod member  69  is connected to a front part of the upper swing arms  13 L,  13 R. The rod member  69  extends downward at an angle, and a lower end  69   b  is connected to one end  71   a  of an L-shaped link  71 . The other end  71   b  of the L-shaped link  71  is connected to a first end  61   a  of the front cushioning unit  61 . A second end  61   b  of the front cushioning unit  61  is connected to the body frame or the engine via a cushioning bracket  73 . An intermediate point  74  of the L-shaped link  71  is supported by the body frame or the engine. 
     As shown in  FIG. 4 , the swing mechanism  60 B is connected to the steering mechanism  60 A. 
     As shown in  FIG. 5 , the front cushioning unit  61  is disposed between the main frames  11   a ,  11   a  so as to extend along the width direction of the vehicle. 
     The lower swing arms  15 L,  15 R that are provided to the left and right are formed so as to protrude away from the vehicle in order to avoid interference with the brake disc or the like during steering. 
     The lower spherical bearing will be described below. 
     As shown in  FIG. 6 , the hub body  76  is housed in the hub  17  of the front wheel via a ball bearing  77  as an axle bearing. The axle bearing may comprise a metal, and the ball bearing preferably has low rotational resistance. An inside diameter Ri of the ball bearing  77  is substantially larger than an outside diameter S of the cross-member  62 . 
     Since the inside diameter Ri of the ball bearing  77  is larger than the size S of the cross-member  62 , the load received from the front wheel  16  can be dispersed over a large surface area. Accordingly, the load of the ball bearing  77  can be reduced. Since the load is dispersed over a large surface area, the cooling performance of the ball bearing  77  increases, and the durability of the ball bearing  77  can be improved. 
     A lower steering shaft  63  is vertically inserted into the hub body  76  at a position that is set apart toward the rear of the vehicle body by a distance P from a center point  79  of the hub body. The lower spherical bearing  82  is attached partway along the lower steering shaft  63 . An outer peripheral surface of the lower spherical bearing  82  is a spherical surface, and the spherical surface is rotatably fitted to the cross-member  62 . The lower steering shaft  63  is secured in place by a nut  81 , and the lower steering shaft  63  can be removed from the hub body  76  by loosening the nut  81 . 
     The lower steering shaft  63  can be rotated across three dimensions by the operation of the lower spherical bearing  82 , with the cross-member  62  as a reference. The center point  79  of the hub body  76  is offset from the center  78  of the lower steering shaft  63  by a distance of P. Accordingly, the hub body  76 , the ball bearing  77 , and the hub  17  can pivot together about the center  78 . 
     The upper spherical bearing will be described below. 
     As shown in  FIG. 7 , upper ends of the left and right knuckle arms  21 L,  21 R are connected by an arm connecting part  83 . The arm connecting part  83  comprises a bottom part  84  in the center; left and right wall parts  85 L,  85 R that rise from the bottom part  84 ; a roof part  86  that covers the top parts of the wall parts  85 L,  85 R; and left and right outer wall parts  87 L,  87 R that are disposed below the left and right wall parts  85 L,  85 R, and that rise from the bottom part  84 . 
     An upper steering shaft  88  is vertically oriented between the bottom part  84  and the roof part  86 . The upper spherical bearing  91  is fitted onto the upper steering shaft  88 , spacers  92 ,  92  for restricting the position of the upper spherical bearing  91  along the vertical direction are provided, and concave parts  93 , which are formed on the distal ends of the upper swing arms  13 L,  13 R, are fitted on the outer surface  91   g  of the upper spherical bearing  91 . The upper steering shaft  88  comprises a shaft part  88   z  and a nut part  88   n.    
     The upper spherical bearing  91 , the spacers  92 ,  92 , the knuckle arms  21 L,  21 R, and the handle link  22  can rotate across three dimensions, with the upper swing arms  13 L,  13 R being used as a reference. 
     The operation of the lower spherical bearing  82  and the upper spherical bearing  91  will be described below. 
     As shown in  FIG. 8A , an imaginary line that connects the lower spherical bearing  82  and the upper spherical bearing  91  represents a pivot shaft  95 . When the front wheel is not being subjected to any force, the angle formed by the upper swing arm  13 L and the pivot shaft  95  is θa 11 , and the angle formed by the line extending from the lower spherical bearing  82  to the center point  79  and the pivot shaft  95  is θa 12 . 
     When force is exerted on the front wheel, the angle θa 12  changes to an angle θa 22 , as shown in  FIG. 8B . In response to this change, the angle θa 11  changes to an angle θa 21 . These changes are not limited to two-dimensional changes within the plane of the diagram, but may also be three-dimensional changes including the direction perpendicular to the plane of the diagram. This is because the lower spherical bearing  82  and the upper spherical bearing  91  are capable of changing along a spherical surface. The lower spherical bearing  82  and the upper spherical bearing  91  are capable of changing over three dimensions independently of one another. Accordingly, the lower steering shaft  63  does not need to be aligned with the pivot shaft  95 , and the upper steering shaft  88  does not need to be aligned with the pivot shaft  95 . 
     The prior art shown in  FIG. 19  must have a lower swing arm  203 , a middle swing arm  204 , an upper swing arm  212 , a middle pin  226 , and an auxiliary link  227 . By contrast, and as shown in  FIG. 1 , only the lower swing arm  15 L and the upper swing arm  13 L are needed in the present invention. In other words, according to the present invention, the middle swing arm  204 , the middle pin  226 , and the auxiliary link  227  are unnecessary. As a result, in a motorcycle in which a front wheel is attached to a body frame by a swing arm, it is possible to provide a structure in which the structure is simplified and manufacturing costs can be reduced. 
     The steering stopper will be described below. 
     As shown in  FIG. 9A , stopper parts  96 ,  96  are provided to an upper surface  62   a  of the cross-member  62 . The stopper parts  96 ,  96  restrict the steering angle of the hub body  76  so as not to exceed a on one side. As shown in  FIG. 9B , a pin part  97  is provided to the hub body  76 , and the pin part comes in contact with the stopper parts  96 ,  96 . 
     Specifically, a steering stopper  98  is incorporated with the hub steering mechanism  20  (see  FIG. 6 ). The steering stopper comprises the stopper parts  96 ,  96 , and the pin part  97 . 
     A steering stopper is normally disposed to the exterior of the hub steering mechanism  20 . When the steering stopper is incorporated with the hub steering mechanism  20 , the outward appearance is better than in a case when the steering stopper is disposed on the outside. Additionally, the cross-member  62  and the hub body  76  are advantageously used, making it possible to prevent the number of components from increasing. 
     The process for removing the front wheel in order to change the tire or the like will be described below. 
     As shown in  FIG. 10 , a first fastening member  101 , which is disposed on a lower part of the knuckle arm  21 R, is loosened. The lower part of the knuckle arm  21 R is then removed from the hub body  76 . A seal member  80  is also removed. 
     A third fastening member  103 , which is disposed on an upper part of the knuckle arm  21 R, is loosened. The upper part of the knuckle arm  21 R is then removed from the arm connecting part  83 . The knuckle  21 R is thus completely removed. 
     A second fastening member  102 , which is disposed on the distal ends of the lower swing arms  15 L,  15 R, is then loosened. The cross-member  62  can thereby be separated from the lower swing arms  15 L,  15 R. The hub body  76 , the ball bearing  77 , the hub  104 , the spokes  105 , the rim  106 , and the tire  107  can then be lowered together with the cross-member  62 . The cross-member  62  and the like are thereby completely removed from the lower swing arms  15 L,  15 R. 
     The tire  107  is then removed from the rim  106 , and replaced with a new tire. The restoration work may also be performed in the reverse order relative to that described above. 
     As is clear from the drawings, first through third fastening members  101  through  103  extend along the width direction of the vehicle, i.e., the longitudinal direction of the cross-member  62 . Accordingly, the first through third fastening members  101  through  103  can be rotated or otherwise manipulated from the side of the vehicle body. As a result, changing the tire and other work can be readily carried out. 
     The operation of the front cushioning unit will be described below with reference to  FIGS. 11A and 11B . 
     As shown in  FIG. 11A , when force is applied to the front wheel  16  in the direction of the arrow b, force is applied to the knuckle arm  21 L in the direction of the arrow p. The upper swing arm  13 L swings about the upper front swing shaft  12 L, and the lower swing arm  15 L swings about the lower front swing shaft  14 L. At this time, force is applied to the rod member  69  in the direction of the arrow q. 
     As a result, as shown in  FIG. 11B , since force is applied to the rod member  69  in the direction of the arrow q, force is applied via the L-shaped link  71  so as to cause the front cushioning unit  61  to retract in the direction of the arrow r. The front cushioning unit  61  absorbs compression force. 
     The front cushioning unit  61  is disposed in a direction that is rotated about 90° from the direction in which the rider is seated; i.e., so as to be parallel to the width direction of the vehicle. The force applied to the front wheel  16  is altered substantially 90° by the L-shaped link  71 , and is applied in the width direction of the vehicle. When the force applied to the front wheel  16  is altered substantially 90° as opposed to being directly applied to the rider, the effect of the force exerted on the rider will be lessened. As a result, the maneuverability of the vehicle can be further improved. 
     The relationship of the upper swing arm and the upper cushioning unit will be described below. 
     As shown in  FIG. 12 , the upper end part  69   t  of the rod member  69  is connected to the center of the substantially V-shape formed by the upper swing arms  13 L,  13 R. Accordingly, the force F applied to the upper swing arms  13 L,  13 R is applied to the center of the vehicle. The lower end part  69   b  of the rod member  69  is connected to the L-shaped link  71 . Accordingly, the force F is transmitted to the front cushioning unit  61  by the rod member  69 . In this case, the force F applied to the upper swing arms  13 L,  13 R is applied to the center of the vehicle; therefore, the force F can be absorbed substantially equally to the left and right. 
     The upper swing arms  13 L,  13 R form a substantial V-shape as viewed from above, are disposed in a left-right symmetrical relationship in the width direction of the vehicle, and are subjected to a force (or a load) in the center of the V-shape. Accordingly, no concerns are presented that an unbalanced load will be applied to the upper swing arm  13 L,  13 R. Since there are no concerns that an unbalanced load will be applied to the upper swing arms  13 L,  13 R, the rigidity necessary in the upper swing arms  13 L,  13 R is lower than in a case in which unbalanced loads are addressed. Reducing the rigidity of the upper swing arms  13 L,  13 R makes it possible to reduce the size and the weight of the upper swing arms  13 L,  13 R. 
     A modification perfected with particular focus on the rod member  69  will be described below. 
     The modification is shown in  FIG. 13 . Specifically,  FIG. 13  differs from  FIG. 4  in that the rod member  69  is changed to a left rod member  69 L and a right rod member  69 R.; the L-shaped link  71  is changed to a left front link  71 L and a right front link  71 R. The left rod member  69 L is connected to a first end  61   a  of the front cushioning unit  61  via the left front link  71 L. The right rod member  69 R is connected to a second end  61   b  via the right front link  71 R. 
     Specifically, the front cushioning unit  61  is held between the left front link  71 L and the right front link  71 R. The force transmitted by the upper swing arms  13 L,  13 R is applied to the left and right rod members  69 L,  69 R. The force applied to the left and right rod members  69 L,  69 R is applied to the first end  61   a  and the second end  61   b  of the front cushioning unit  61 , and the force applied to the front wheel  16  can be equally absorbed on the left and right sides. 
     A separate embodiment of the motorcycle of  FIG. 1  will be described below with reference to  FIG. 14 . 
     The motorcycle according to the separate embodiment, as can be appreciated from  FIG. 14 , differs from  FIG. 1  in that the main frames are omitted, and the upper swing arm  13 L, the lower swing arm  15 L, and the upper and lower arm members  33 L,  34 L are directly mounted on the engine  26 . 
     The engine  26  functions as the main frame, whereby the weight of the vehicle can be reduced. 
     The steering handle and a peripheral part thereof will be described below. 
     As shown in  FIG. 15  with reference to the handle link  22 , the lower end part  22   b  is attached to the left and right knuckle arms  21 L,  21 R via pin members  94 ,  94 ; and the upper end part  22   a  is attached to the steering handle  23 . 
     As shown in  FIG. 16 , upper and lower head pipes  28   t ,  28   b , which rotatably support the steering handle  23 , are provided to a distal end of the handle support frame  27 . A cylindrical member  113  is disposed between the upper and lower head pipes  28   t ,  28   b . The cylindrical member tightens the steering handle  23  and the handle link  22  together via a tightening bolt  112  used as a horizontal member  111 . 
     Specifically, a front wheel steering device  124  is provided with the horizontal member  111 , which is horizontally provided along the width direction of vehicle body, and transmits steering force applied to the steering handle  23  to the handle link  22 ; and engaging holes  119 ,  125   b , which are provided to the steering handle  23  and the handle link  22 , and are formed so as to engage the horizontal member  111 . 
     Bosses  114 ,  114  (see  FIG. 17 ) are formed on both lateral surfaces of the cylindrical member  113 . Second engaging holes  115 ,  115  are formed in the bosses  114 ,  114  as threaded holes, so that the tightening bolts  112 ,  112  can be threaded thereinto. 
     The steering handle  23  is provided with a steering shaft  116  that is inserted into and rotatably provided to the head pipes  28   t ,  28   b ; a lateral part  117  that is horizontally provided to an upper end of the steering shaft  116 ; and upper pin attachment parts  118 ,  118  that are provided to both ends of the lateral part  117  so as be substantially parallel to the steering shaft  116 . The hole parts  119 ,  119  through which the fastening bolts  112 ,  112  are inserted are formed in the upper pin attachment parts  118 ,  118 . 
     The steering handle  23  is provided with the steering shaft  116 , which is rotatably supported by the head pipes  28   t ,  28   b . The steering shaft  116  is supported on the head pipes  28   t ,  28   b  so as to be capable of rotating above and below the cylindrical member  113 , which functions as a connecting part of the horizontal member  111 . As a result, the rigidity of the steering shaft  116  is increased, the strength and rigidity of the other members can be reduced, and the weight can be reduced. 
     The steering shaft  116  and the steering handle  23  are connected by the horizontal member  111 . Specifically, the steering handle  23 , the handle link  22 , and the steering shaft  116  are connected via the horizontal member  111 . Consequently, the support rigidity of the handle link  22  can be increased. As a result, the necessary rigidity of the other members can be reduced, and weight can be reduced. 
     In the present embodiment, fastening bolts have been used as the horizontal member, but pins, keys, or other such members may also be used. 
     As shown in  FIG. 17 , the cylindrical member  113 , which has a fitting hole  120  into which the steering shaft  116  is fitted, is placed between the upper and lower head pipes  28   t ,  28   b.    
     First engaging holes  121 ,  121  formed in the upper end part  22   t  of the handle link  22  are aligned with the second engaging holes  115 ,  115  of the cylindrical member  113 . The hole parts  119 ,  119  of the steering handle  23  are aligned with the second engaging holes  115 ,  115 . The fastening bolts  112 ,  112 , which are used as the horizontal member  111 , are threaded into the second engaging holes  115 ,  115  from the exterior on the left and right sides. 
     Connecting the handle link  22  and the steering handle  23  makes it possible to secure the steering handle  23  to the steering shaft  116  without forming a spline in the steering shaft  116 . Since a spline is not necessary, manufacturing costs associated with the steering shaft  116  can be reduced. 
     A steering stopper  98 B for restricting the steering angle of the front wheel can be provided to the steering handle  23 . 
     Specifically, a pin part  97 B protrudes forward and downward from the lateral part  117 . Two left and right stopper parts  96 B,  96 B are formed on the upper head pipe  22   t . The pin part  97 B comes in contact with the left and right stopper parts, and the steering angle of the steering handle  23  is restricted. 
     It is also possible for a steering stopper  98 C to be provided instead of the steering stopper  98 B. In the steering stopper  98 C, which is shown by the imaginary lines, a pin part  97 C is provided to an outer peripheral front end part of the cylindrical member  113  on the upper part of the handle link  22 , and stopper parts  96 C,  96 C formed to the left and the right, with which the pin part  97 C comes into contact, are provided to the lower head pipes  28   t ,  28   b.    
     The process of attaching the steering handle to the steering link will be described in detail below with reference to  FIGS. 18A through 18C . 
     As shown in  FIG. 18A , a lower end part  22   b  of the handle link  22  is attached to the knuckle arms  21 L,  21 R. 
     As shown in  FIG. 18B , a cylindrical member  113  is disposed between the upper and lower head pipes  28   t ,  28   b , the upper end part  22   t  of the handle link  22  is raised, and the steering shaft  116  of the steering handle  23  is inserted into a steering hole  122 . The first engaging holes  121 ,  121 , which are formed in the upper end of the handle link  22  as engaging holes  125 , and the hole parts  119 ,  119  of the steering handle  23  are aligned with the second engaging holes  115 ,  115  of the cylindrical member  113 . The fastening bolts  112 ,  112  are threaded into these holes from the exterior on the left and right. 
     As shown in  FIG. 18C , the steering handle  23  is attached to the handle link  22 . 
     The fastening members  112  are inserted into the engaging holes  119  of the steering handle  23  and the engaging holes  121  of the handle link  22 , and the handle link  22  is secured in the second engaging holes  115  of the cylindrical member  113  via the fastening members  112 . The phase of the handle link  22  can be simultaneously aligned with the phase of the steering handle  23 . 
     Specifically, it is possible to eliminate labor involved in fine tuning related to phase-aligning the steering angle of the steering handle  23 . 
     Obviously, various minor changes and modifications of the present invention are possible in 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.