Patent Document

FIELD OF THE INVENTION 
   The present invention relates to a rider restriction device of a two-wheeled vehicle, and more particularly to a rider restriction device of a two-wheeled vehicle which restricts a lower half part of a rider from moving in the forward direction of the vehicle body. 
   BACKGROUND OF THE INVENTION 
   Japanese Patent 2705775 discloses a technique for restricting a lower half part of a rider from moving toward a front portion of a vehicle body in a four-wheeled automobile that arranges an impact absorbing member on a lower portion of an instrument panel cabin and at a position which faces knees of the rider. 
   The technique described in Japanese Patent 2705775 is proposed on the premise that a support member which supports the impact absorbing member is provided in front of the knee portions of the rider and hence, the technique is not applicable to a vehicle such as a motorcycle which has no support member in front of the knee portions of the rider. 
   It is an object of the present invention to solve the above-mentioned drawback of the above-mentioned related art and can restrict a lower half part of a rider on a two-wheeled vehicle from moving in the frontward direction of the vehicle body. 
   SUMMARY OF THE INVENTION 
   To achieve the above-mentioned object, the present invention is characterized in that following means are provided in a rider restriction device which restricts the movement of a rider of a two-wheeled vehicle in the direction toward a front portion of a vehicle body. 
   A rider restriction device is provided comprising a pair of left and right knee portion pads; a pipe-like pad support member which mounts the knee portion pads on one end side thereof; a fixing member which fixes another end side of the pad support member in a state that the knee portion pads face knee portions of the rider; and a load absorbing member which absorbs a forward load applied to the knee portion pads thus restricting the plastic deformation of the pad support member. 
   A portion of a load applied to the knee portion pad is consumed and absorbed by a load absorbing member and hence, the plastic deformation of the pad support member can be restricted. Accordingly, even when a frontward load in which a stress applied to the pad support member exceeds an elastic limit is applied to the knee portion pad, the frontward load is received whereby it is possible to surely restrict the rider. 
   The load absorbing member may comprise a collapse prevention member which restricts the collapse deformation of the pad support member. Therefore, it is possible to easily restrict the plastic deformation of the pad support member without applying a particular forming on the pad support member. 
   The load absorbing member may be a resilient member or a coil spring which is inserted into a plastic deformation portion of the pad support member. It may also be a bellows-like collapsible body which is formed on the pad support member. It is possible to restrict the plastic deformation of the pad support member by merely adding the resilient member, the coil spring or the bellows-like collapsible body. 
   The fixing member may be a pipe-like connecting bar that is connected with another end side of the pad support member perpendicularly and extends in the lateral direction of a vehicle body, and the load absorbing member is a resilient member which is inserted in the inside of the connecting bar and restricts the torsional deformation of the connecting bar. In a constitution which imparts the elasticity to the pad support member by making use of a torsional stress of the connecting bar, it is possible to easily restrict the plastic deformation of the connecting bar. 
   The rider restriction device may further include a reinforcing member which restricts a front tilting amount of the pad support member. Since the front inclination amount of the handle connecting member can be restricted, it is possible to maintain the position of the restricting pad at a given height or more. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  A side view of a scooter-type motorcycle to which a rider restriction device of the present invention is applied. 
       FIG. 2  A front view of a knee portion pad. 
       FIG. 3  A view showing a state in which the movement of a rider is prevented by the knee portion pad. 
       FIG. 4  A side view of a load absorbing portion. 
       FIG. 5  A cross-sectional view of a first embodiment of the load absorbing portion. 
       FIG. 6  A cross-sectional view of a second embodiment of the load absorbing portion. 
       FIG. 7  A cross-sectional view of a third embodiment of the load absorbing portion. 
       FIG. 8  A cross-sectional view showing one example of a reinforcing member which restricts an inclination angle of a handle pipe. 
       FIG. 9  A side view of a fourth embodiment of the load absorbing portion. 
       FIG. 10  A front view of the fourth embodiment of the load absorbing portion. 
       FIG. 11  A view showing the relationship between a moving amount of the knee portion pad and a load applied to a rider. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   An embodiment of the present invention is explained hereinafter in detail in conjunction with drawings.  FIG. 1  is a side view of a scooter-type motorcycle to which a rider restriction device of the present invention is applied. A vehicle body frame  10  includes a main frame pipe  12  which fixes a head pipe  11  on a front end portion thereof, a cross pipe  13  which is fixedly secured to a rear end portion of the main frame pipe  12  at a right angle and horizontally, and a pair of rear frame pipes  14  ( 14 L,  14 R) which have respective front ends thereof contiguously formed on both end portions of the cross pipe  13  as main constitutional parts. 
   The above-mentioned main frame pipe  12  is constituted by integrally and contiguously forming a down frame portion  12   a  which is inclined rearwardly and downwardly and spaced rearwardly from the head pipe  11  and a lower frame portion  12   b  which is extended rearwardly from a rear end of the down frame portion  12   a  in a substantially horizontal posture. The above-mentioned cross pipe  13  extends in the lateral direction from the vehicle body frame  10  and a rear end portion of the above-mentioned main frame pipe  12  is fixedly secured to a center portion of the cross pipe  13  at a right angle. The above-mentioned pair of left and right rear frame pipes  14  are constituted by integrally and contiguously forming rising frame portions  14   a  which extend rearwardly and upwardly from both end portions of the cross pipe  13  and upper frame portions  14   b  which extend rearwardly from rear ends of the rising frame portions  14   a  and, at the same time, are curved in a horizontal plane such that openings of rear end portions thereof face each other in an opposed manner. 
   On the above-mentioned head pipe  11 , a front fork  15  which constitutes a steering member for supporting a front wheel Wf is steerably supported. To an upper end of the front fork  15 , a steering handle  16  is connected by way of a handle pipe  20  which constitutes a handle connecting member. On a front portion of the above-mentioned rear frame pipe  14 , a power unit P which is formed of an engine E which is arranged on a front side of a rear wheel Wr and a variable-speed transmission M which is arranged on a left side of the rear wheel Wr is tiltably supported in the vertical direction. The rear wheel Wr is pivotally supported on a rear portion of the power unit P. An air cleaner  29  is arranged on a left side of an upper portion of the rear wheel Wr. 
   Between a rear portion of the power unit P and the left-side rear frame pipe  14 L, a rear cushion unit  17  is provided. An exhaust pipe  18  which guides an exhaust gas from the engine E extends toward a right side of the rear wheel Wr from the engine E, while the exhaust pipe  18  is connected with an exhaust muffler  19  which is arranged on a right side of the rear wheel Wr. Between front portions of the left and right rear frame pipes  14 , an accommodation box  25  is supported in a state that the accommodation box  25  is arranged above the above-mentioned engine E. 
   The vehicle body frame  10  is covered with a vehicle body cover  21  made of synthetic resin, wherein the vehicle body cover  21  includes a leg shield  22  which covers a front portion of a leg of a rider, a step floor  23  which is contiguously formed with a lower portion of the leg shield  22  to allow the leg of the rider to be placed thereon and a side cover  24  which is contiguously formed with the step floor  23  and covers a rear end portion of the vehicle body from both sides. 
   The above-mentioned accommodation box  25  and fuel tank (not shown in the drawing) are covered with the above-mentioned side cover  24 , while a seat  26  which covers the accommodation box  25  from above is mounted on an upper portion of the side cover  24  in a state that the seat  26  can be opened and closed. That is, the step floor  23  is formed on the vehicle body cover  21  in a state that the step floor  23  is arranged between the steering handle  16  and the seat  26  and, below a rear end of the step floor  23 , a frame-side bracket  27  which is provided for tiltably supporting the power unit P on the vehicle body frame  10  is arranged. 
   To explain the embodiment also in conjunction with  FIG. 2 , a plate member  31  is fixed to the above-mentioned steering handle  16 , and a breast portion pad  30  is mounted on the plate member  31  in a state that the breast portion pad  30  faces a rider who sits on the seat  26  in an opposed manner. Further, in this embodiment, a connecting member  53  is fixed to a lower portion of the head pipe  11 , and a pair of left and right pad support pipes  52 (L, R) are erected from the connecting member  53  in a state that the pad support pipes  52  are directed in the oblique upward direction along the handle post  11 . On upper portions of the respective pad support pipes  52 , a pair of left and right knee portion pads  50 (L, R) are mounted in a posture that the knee portion pads  50  are directed toward knee portions of a rider by way of the respective plate members  51  (L, R). 
   With a provision of these knee portion pads  50 , as indicated by a broken line in  FIG. 3 , even when a lower half part of the rider is moved frontwardly due to an inertia at the time of braking or the like, the knee portions of the rider are pushed by the knee portion pads  50  and the further movement of the knee portions of the rider is prohibited and hence, the frontward movement of the rider is restricted within a given range. Further, according to this embodiment, when a frontward load which exceeds a given reference value is applied to the knee pads  50 , a load absorbing function which absorbs the frontward load and alleviates a load applied to the rider is imparted to the above-mentioned pad support pipe  52 . 
     FIG. 4  is a side view for explaining the above-mentioned load absorbing function. When the frontward load which exceeds the given reference value is applied to the above-mentioned knee portion pads  50 , the above-mentioned pad support pipe  52  starts a frontward deflection thereof in the vicinity of an upper surface of the above-mentioned connecting member  53 . When a stress exceeds a yielding point (a stress limit) of the pad support pipe  52 , the plastic deformation starts and hence, as indicated by a broken line in the drawing, the pad support pipe  52  starts a frontward bending thereof. 
   In general, when a yielding point of a material exceeds a stress limit, an elastic force is lost and hence, the above-mentioned knee portion pads  50  cannot receive the frontward load attributed to the knee portions. In this embodiment, however, as explained in detail later, a load absorbing portion is formed on the above-mentioned pad support pipe  52  and hence, the pad support pipe  52  can maintain the elasticity even when the pad support pipe  52  exceeds the stress limit. 
     FIG. 5  is a cross-sectional view of a first embodiment of the above-mentioned load absorbing portion and symbols equal to the above-mentioned symbols indicate identical or similar portions. In this embodiment, the pad support pipe  52  has a lower end portion thereof fixed to a connecting member  53  in a state that the lower end portion is inserted in and penetrates the connecting member  53 , while a longitudinal elastic member  55  penetrates in and is fixed to the inside of the lower end portion. 
   In such a constitution, when a frontward load which exceeds a given reference value is applied to the above-mentioned knee portion pad  50 , the above-mentioned pad support pipe  52  starts a deflection thereof. When a stress exceeds a yielding point of the pad support pipe  52 , the plastic deformation starts and, as indicated by a chain line in the drawing, the pad support pipe  52  starts bending in the frontward direction. 
     FIG. 11  shows the relationship between a frontward moving amount of the above-mentioned knee portion pad  50  and the load applied to the knee portions of the rider. When the above-mentioned elastic member  55  is not inserted into the pad support pipe  52 , as indicated by a broken line in the drawing, at a point of time that the stress exceeds the yielding point, the pad support pipe  52  is ruptured or collapsed and hence, the elasticity can not be maintained whereby the load applied to the knee portion pad  50  is escaped. 
   To the contrary, according to this embodiment, the pad support pipe  52  and the connecting member  53  are firmly connected to each other and, at the same time, both members are elastically connected with each other by the above-mentioned elastic member  55  and hence, even in a plastic region where the stress exceeds the yielding point, there is no possibility that the pad support pipe  52  is ruptured or collapsed whereby the elasticity can be maintained. Accordingly, the relationship between the forward moving amount of the above-mentioned knee portion pads  50  and the load applied to the knee portion of the rider is held at an approximately fixed value even after the pad support pipe  52  exceeds the yielding point whereby even when the load which exceeds the stress limit of the pad support pipe  52  is applied to the above-mentioned knee portion pad  50 , a portion of the load is absorbed so that the load applied to the rider can be reduced. 
     FIG. 6  is a cross-sectional view of a second embodiment of the above-mentioned load absorbing portion and symbols equal to the above-mentioned symbols indicate identical or similar portions. In this embodiment, the pad support pipe  52  has a lower end portion thereof fixed to a connecting member  53  in a state that the lower end portion is inserted in and penetrates the connecting member  53 , while a coil spring  56  penetrates in and is fixed to the inside of the lower end portion. 
   In such a constitution, when a frontward load which exceeds a given reference value is applied to the above-mentioned knee portion pad  50 , the above-mentioned pad support pipe  52  starts a deflection thereof. When a stress exceeds a yielding point of is the pad support pipe  52 , the plastic deformation starts and, as indicated by a chain line in the drawing, the pad support pipe  52  starts bending in the frontward direction. However, in this embodiment, since the coil spring  56  is inserted into the inside of a bent portion of the pad support pipe  52 , even when the pad support pipe  52  exceeds its own yielding point, the pad support pipe  52  is neither broken or collapsed whereby the resiliency can be maintained. Accordingly, even when the load which exceeds the stress limit of the pad support pipe  52  is applied to the knee portion pad  50 , a portion of the load is absorbed so that the load applied to the rider can be reduced. 
     FIG. 7  is a cross-sectional view of a third embodiment of the above-mentioned load absorbing portion and symbols equal to the above-mentioned symbols indicate identical or similar portions. In this embodiment, the pad support pipe  52  has a lower end portion thereof fixed to a connecting member  53  in a state that the lower end portion is inserted in and penetrates the connecting member  53 , while a bellows-like collapsible body  57  is formed in the vicinity of an upper portion of the connecting member  53 . 
   In such a constitution, when a frontward load which exceeds a given reference value is applied to the above-mentioned knee portion pad  50 , the above-mentioned pad support pipe  52  starts a deflection thereof. When a stress exceeds a stress limit of the bellows-like collapsible body  57 , a front portion side of the bellows-like collapsible body  57  is collapsed and the plastic deformation in which a lower portion side of the bellows-like collapsible body  57  extends starts and hence, the pad support pipe  52  starts the frontward bending. 
   In this manner, since the bellows-like collapsible body  57  is formed on the pad support pipe  52  in this embodiment, even after the plastic deformation starts, the pad support pipe  52  can maintain the elasticity without causing rupture. Accordingly, even when the load which exceeds the stress limit of the pad support pipe  52  is applied to the knee portion pad  50 , a portion of the load is absorbed whereby the load applied to the rider can be reduced. 
   Here, in the above-mentioned respective embodiments, since the pad support pipe  52  is deflected, corresponding to the increase of a moving amount of the knee portion pad  50 , the position of the knee portion pad  50  is lowered. Accordingly, as shown in  FIG. 8 , in this embodiment, a reinforcing member  58  which restricts a front inclination angle, that is, the moving amount of the knee portion pad  50  is provided below the above-mentioned bending portion of the pad support pipe  52 . Due to such a constitution, even when the large frontward load is applied to a restriction pad  30 , it is possible to maintain the position of the restriction pad  30  at a given height or more. 
     FIG. 9  is a side view with a part broken away of a fourth embodiment of the above-mentioned load absorbing portion, wherein symbols which are equal to the above-mentioned symbols indicate identical or similar portions. 
   A pipe-like connecting bar  61  penetrates the frame in the lateral direction and is firmly connected using suitable means such as welding or the like. Pad support arms  59 (L, R) are vertically mounted on the above-mentioned connecting bar  61 , while the pad support arms  59  are extended upwardly in the rear oblique direction using the above-mentioned connecting bar  61  as a fulcrum. On upper end portions of the above-mentioned pad support arms  59 , the above-mentioned knee portion pad  50  is positioned and fixed by way of the plate members  51 (L, R) in a state that the knee portion pad  50  is directed toward the knee portions of the rider. As shown in  FIG. 10 , in the inside of the connecting bar  61 , a collapse preventing member  62  is filled or inserted. Even after a torsional stress exceeds an elastic limit and the plastic deformation which generates a collapse of the connecting member  61  starts, the collapse preventing member  62  restricts this collapse and allows the above-mentioned connecting bar  61  to maintain a given elastic force. 
   In such a constitution, when the frontward load is applied to the above-mentioned knee portion pad  50  and a twisting is generated on the connecting bar  61 , the pad support arms  59  start the frontward movement. When the frontward load is further applied and, the torsional stress which is applied to the above-mentioned connecting bar  61  exceeds a yielding point (a stress limit) of the connecting bar  61 , the plastic deformation (collapse deformation) starts and, as indicated by a broken line in  FIG. 9 , the pad support arm  59  is rotated in the frontward direction using the connecting bar  61  as a fulcrum. Here, in this embodiment, since the collapse preventing member  62  is inserted in the inside of the connecting bar  61 , the collapse of the connecting bar  61  is restricted whereby the connecting bar  61  can maintain the elasticity even in the plastic region which exceeds the yielding point. Accordingly, even when the load which exceeds the stress limit of the pad support arms  59  is applied to the knee portion pad  50 , a portion of the load is absorbed and hence, the load applied to the rider can be reduced. 
   Although embodiments of the present invention have been described thus far, the present invention is not limited to the examples in the drawings and the embodiments described above, and various modification may be made without departing the scope of the present invention, as a matter of course.

Technology Category: 7