JP2008162541A - Steering mechanism of two-wheeler - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve spin limit performance at the cornering of a two-wheeler, and to secure safety at the cornering in order to solve a problem that, in a conventional two-wheeler steering mechanism, it is difficult to secure due to the generation of a spin caused by the shortage of a cornering force at a rear tire with respect to a centrifugal force, when the two-wheeler turns at a corner at high speed of on a set road face such as a turn in a two-wheeler race. <P>SOLUTION: This steering mechanism for the two-wheeler includes a frame which has been an integrated structure in a conventional arrangement, and now structured so that a front fork and a main frame are tied together by new components, i.e. an upper frame 6, lower frames 7a and 7b, and a strut bar 27, whereby the front fork and a rear fork can bend freely. At cornering, a two-wheeler body bends in a tying part by a centrifugal force and the balancing operation of a rider. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a steering mechanism used for a motorcycle.

  Conventionally, a rider who operates a two-wheeled vehicle lays down the two-wheeled vehicle when turning and turns a steering wheel to perform cornering. At this time, the steering mechanism transmits the steering wheel movement to the front tire, thereby determining the traveling direction of the motorcycle.

  As described above, the two-wheeled vehicle steering mechanism according to the related art has no problem in turning the corner by turning the steering wheel at a normal speed, but when turning the corner on a high-speed or wet road surface as seen in a motorcycle race or the like. The cornering force of the rear tire is insufficient for the centrifugal force of the motorcycle, causing a spin and it is difficult to ensure safety. The present invention has been made in view of these points, and its purpose is to improve the spin limit performance in cornering of a motorcycle on a high speed or wet road surface, and to improve safety in cornering. It is to secure.

  The two-wheeled vehicle steering mechanism according to the present invention that achieves the above-described object is a new two-wheeled vehicle frame that includes a front fork part that supports the front wheel of the two-wheeled vehicle and a main frame part that supports the rear wheel, engine, and drive unit. The upper arm, lower arm, and strut bar provided are connected so that the front fork and the main frame can be freely bent within a certain range. It is characterized in that the vehicle body bends from the part.

  As described above, according to the present invention, the front fork portion that supports the front wheels of the two-wheeled vehicle and the main frame portion that supports the rear wheels, the engine, and the drive unit are newly provided in front of the rider seat and the two upper arms. By connecting the lower arm and one strut bar, the frame that fixes the rear wheel from the joint is bent outward by the centrifugal force when the two-wheeler is turning the corner, and the front and rear wheels are reversed. By breaking the phase and continuing cornering, the motorcycle is laid down and the rider leans over and lays down the body in the direction of gravity, and by bending the frame supporting the rear wheel from the joint in the turning direction, The rear wheels can be cut in the same phase. This improves the spin limit performance during cornering and is extremely effective for turning the corner safely.

  Embodiments of the present invention will be described below in detail with reference to the drawings. The two-wheeled vehicle steering mechanism according to this embodiment is applied to a two-wheeled vehicle frame. FIG. 1 is an external perspective view of a typical cradle-shaped frame of a conventional two-wheeled vehicle. As shown in FIG. , Tank rail 2, seat rail 3 and down tube 5. These parts are all connected by welding, and the frame itself is not movable left and right.

  In the case of a two-wheeled vehicle steering mechanism having such a frame, when turning a corner, the steering wheel is turned and the vehicle body is laid down and passed. However, when turning corners at high speeds as seen in races or corners on wet roads, there is a possibility that the cornering force of the rear wheels will be insufficient for the centrifugal force applied to the motorcycle and cause spin. There is. Such a phenomenon can also occur in a general motorcycle.

  In order to avoid such a phenomenon, the present invention is designed to improve the spin limit performance during cornering and to bend the corner safely by changing the direction of the front wheel and the rear wheel of the motorcycle during cornering. It is a thing.

  FIG. 2 is an external perspective view of the movable frame of the present invention, and FIG. 3 is a plan view of the movable frame. As shown in FIGS. 2 and 3, the movable frame of the present invention includes a front fork (not shown) having a head pipe 1 and a main frame composed of a tank rail 2, a seat rail 3 and a down tube 5. As shown in FIG. 4, the front fork portion and the main frame portion are connected by one upper arm 6, two lower arms 7, and one strut bar 27. The fork can be moved left and right.

  5 is a cross-sectional view taken along the line AA of FIG. 3, and FIG. 6 is a partially enlarged view thereof. As shown in FIGS. 5 and 6, in order to move the main frame portion composed of the head pipe 1 to which the front fork is attached, the tank rail 2, the seat rail 3, and the down tube 5 from side to side, One end of the upper arm 6 is welded to the head pipe bracket 17 of the head pipe 1, and a rotating pipe 25 is welded to the other end. The rotating pipe 25 is attached to the rotating shaft 21 welded to the connecting tube A9. The upper arm 6 is inserted and fixed with a presser plate 23 and a bolt 24 so that the upper arm 6 can be easily rotated. The rotating shaft 21 is provided at a position between the seat 16 and the fuel tank 15 so that the rider can easily control the rotating shaft 21. Further, a portion of the fuel tank 15 through which the upper arm 6 penetrates is provided with a space (not shown) so that the upper arm 6 can move left and right.

  On the other hand, as shown in FIG. 3, the two lower arms 7 are separately fixed to the connection tube B <b> 10 that connects the head pipe 1 and the left and right down tubes 5. 7 is a cross-sectional view taken along the line B-B of FIG. 6, and one end of the lower arm 7 is fixed to a head pipe bracket 17 welded to the head pipe 1 via a front rubber bush 18 as shown in FIG. 7. Yes. FIG. 8 is an enlarged view of the arrow C in FIG. 5. As shown in FIG. 8, the other end of the lower arm 7 is connected to the left and right lower arm brackets 26 welded to the connecting tube B10 via the rear rubber bushings 19. It is fixed.

  In the above-described structure, the upper arm 6 and the lower arm 7 receive the braking force from the front wheel from the front fork during the weight of the vehicle body and braking. Therefore, as shown in FIGS. 2 and 5, these loads are received by one strut bar 27 attached to the connecting tube C <b> 11 of the upper arm 6 and the down tube 5. FIG. 6 is an enlarged view showing details of the strut bar 27, and a strut upper bracket 29 welded to the upper arm 6 and a strut lower bracket 32 welded to the connecting tube C 11 of the down tube 5 and an upper ball joint 30 integrated with the strut bar 27. The lower ball joint 31 connects the upper arm 6 and the connecting tube C11 to receive the load in the vertical direction. On the other hand, the load in the front-rear direction has a frame structure that is received by the upper arm 6 and the lower arm 7.

  Since the two-wheeled vehicle frame can be moved left and right by the movable frame structure as described above, the front and rear wheels are separately angled within a certain range by the action of centrifugal force and the movement of the rider during traveling. Will be able to.

  9 and 10 show an embodiment of the movable frame of the present invention. When the two-wheeled vehicle having the movable frame structure as described above reaches the corner and the handle is turned to the left and centrifugal force is applied to the two-wheeled vehicle, the frame is the main frame part that supports the rear wheel and the outer arm with the fulcrum 8 of the upper arm 6 as the axis. Therefore, as shown in FIG. 9, the direction in which the rear wheel cuts is opposite in phase to the direction in which the front wheel cuts. When the cornering is continued and the centrifugal force applied to the two-wheeled vehicle becomes tight, the rider leans out and puts his weight in the direction of gravity, so that the main frame part is bent inward as shown in FIG. 10, and the rear wheel is the same as the front wheel. It cuts in the direction and becomes the same phase. By doing so, the spin limit performance during cornering of the motorcycle is improved, and the corner can be bent safely.

  The present invention can be used in the industrial field of manufacturing and selling motorcycles.

  It is an external perspective view of a typical cradle-shaped frame of a conventional motorcycle.   It is an external appearance perspective view of the movable frame of this invention.   FIG. 3 is a plan view of FIG. 2.   It is a top view which shows the state which the movable frame of this invention swung to right and left.   It is AA sectional drawing of FIG.   It is an enlarged view of the movable part of FIG.   It is an enlarged view of the BB cross section of FIG.   It is an enlarged view of the external appearance by arrow C of FIG.   It is an Example in which the front and rear wheels of the movable frame of the present invention show an opposite phase state.   This is an embodiment in which the front and rear wheels of the movable frame of the present invention show the same phase state.

Explanation of symbols

1: head pipe 2: tank rail 3: seat rail 4: pivot 5: down tube 6: upper arm 7: lower arm 8: fulcrum 9: connecting tube A
10: Connection tube B
11: Connection tube C
12: Connection tube D
13: Seat bracket 14: Connection tube E
15: Fuel tank 16: Seat 17: Head pipe bracket 18: Front rubber bush 19: Rear rubber bush 20: Bush bolt 21: Rotating shaft 22: Reinforcement bracket 23: Presser plate 24: Bolt 25: Rotating pipe 26: Lower arm bracket 27: Strut bar 28: Strut upper bolt 29: Strut upper bracket 30: Upper ball joint 31: Lower ball joint 32: Strut lower bracket 33: Strut lower bolt 34: Front wheel 35: Front wheel center line 36: Rear wheel 37: Rear wheel center line 38 : Front wheel center radius 39: Rear wheel center radius

Claims (7)

  The front fork part that supports the front wheel of the motorcycle and the main frame part that supports the rear wheel, engine and drive unit are separated and connected by the newly provided upper arm, lower arm and strut bar, and the front fork part and the main frame part are cornered. A two-wheeled vehicle steering mechanism that can be moved to the left and right sometimes.   The two-wheeled vehicle steering mechanism according to claim 1, wherein the movable frame is movable left and right around a portion between a fuel tank and a seat of the two-wheeled vehicle as a fulcrum.   The steering mechanism for a motorcycle according to claim 1, wherein the front fork portion and the main frame portion are connected by one upper arm, two lower arms, and one strut bar.   4. The two-wheeled vehicle steering mechanism according to claim 1, wherein both ends of the lower arm are connected by rubber bushes so that the left and right movements of the upper arm can be followed.   4. The two-wheeled vehicle steering mechanism according to claim 1, wherein the upper arm and the lower arm receive a vehicle body weight and a braking force from a front wheel during braking from a front fork, and therefore a strut bar is provided to compensate for these loads. A motorcycle steering mechanism.   6. The two-wheeled vehicle steering mechanism according to claim 5, wherein the strut bar is freely movable in the left-right direction of the upper arm, and ball joints are used at both ends of the strut bar so that the movement can be restricted in the vertical direction. The steering mechanism for motorcycles.   The two-wheeled vehicle steering mechanism according to any one of claims 1 to 6, wherein when the two-wheeled company points to the corner and a centrifugal force is applied, the main frame that supports the rear wheel is directed outward by the centrifugal force, and the front and rear wheels are It will be in an antiphase state. If the rider continues to enter the corner, the rider lays down the motorcycle, leans out and puts weight in the direction of gravity, so that the main frame faces inward and the front and rear wheels are in phase. Steering mechanism.

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