JP2799165B2 - Height adjustment device for motorcycles - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a vehicle height adjusting device for a motorcycle. 2. Description of the Related Art As a suspension mechanism for a rear wheel of a motorcycle, a rear cushion unit having a coil-shaped suspension spring disposed outside a damper is interposed between a swing arm supporting the rear wheel and a vehicle body. Things are generally known. [0003] The spring load of the suspension spring increases while maintaining a linear proportional relationship with the swing of the swing arm. However, by adjusting the initial load of the suspension spring, the initial angle of the swing arm changes. The vehicle height can be adjusted. For this reason, one end of the suspension spring is supported via a cylindrical cam attached to a damper, and the initial compression amount of the suspension spring is adjusted by rotating the cylindrical cam to change the supporting position.
The vehicle height is changed by adjusting the amount of damper extension. [0005] However, in such a vehicle height adjusting device, it is necessary to rotate the cam against the load of the suspension spring when adjusting the vehicle height. However, there was a problem that the operation was very difficult, and the height could be adjusted only by a few steps because of the height adjustment by the cam, so that fine adjustment was not possible and the adjustment width was narrow. Therefore, the present invention makes it possible to easily adjust the vehicle height,
It is another object of the present invention to provide a vehicle height adjustment device for a two-wheeled vehicle capable of adjusting a small adjustment width steplessly. SUMMARY OF THE INVENTION The present invention relates to a two-wheeled vehicle in which a rear wheel is supported by a swing arm rotatably connected to a vehicle body and a damper is interposed between the swing arm and the vehicle body. The base end of the swing arm is rotatably connected to the swing shaft supported by the vehicle body, and a torsion coil spring that urges the swing arm toward the extension side of the damper is wound around the swing shaft, and the swing shaft is Attaches the base end of the arm freely to rotate,
One end of the torsion coil spring was connected to the swing arm, and the other end was connected to the arm, and the free end of the arm was connected to the vehicle body via a turnbuckle. In the present invention, when the angle of the arm is changed by operating the turnbuckle, the balance position of the torsion coil spring changes, the swing angle of the swing arm with respect to the vehicle body changes, and the vehicle height changes. An embodiment of the present invention will be described with reference to FIGS. In FIG. 1, 1 is a swing arm, and 2 is a frame of a vehicle body. As shown in FIG. 2, an end of the swing arm 1 is swingably connected to the frame 2, and the other end of the swing arm 1 supports the rear wheel 3 so as to rotate freely. The connection between the swing arm 1 and the frame 2 is configured as follows. That is, the pipe 4 extends perpendicularly to the end of the swing arm 1.
Are solidified, and the center bolt 5 whose center is inserted through the hollow bolt 6 penetrates. The hollow bolt 6 is divided into left and right parts at the center and sandwiches the bush 7 in the middle, while the frame 2 is held between each tip part protruding outside the pipe 4 and both ends of the center bolt 5 protruding further outside. These are clamped and tightened by a nut 8 screwed to one end of the center bolt 5. The hollow bolt 6 is a ball bearing 9
The pipe 4 is rotatably supported via the. On the other hand, an arm 10 is rotatably attached to the bush 7 and protrudes upward from a slit 11 formed in the center of the pipe 4 and a dust boot 12 covering the same. The arm 10 has a turnbuckle 13 as shown in FIG.
And is rotationally displaced within a certain range with respect to the bush 7 by operating the turnbuckle 13. Further, holders 16 provided with bearings 15 for slidingly supporting the pipe 4 are arranged on both sides of the arm 10 in the pipe 4, and engage with a holder engaging portion 10A protruding from the arm 10 as shown in FIG. . This holder 1
The inner sides of the pipes 4 on the left and right sides of the arm 10 are respectively defined from outside by the ball bearing 6 and the ball bearing 9 described above, and the torsion coil spring 17 is housed therein. One end of the torsion coil spring 17 contacts a stopper 18 fixed inside the pipe 4 as shown in FIG. 4, and the other end contacts a stopper 19 projecting sideways from the holder 16. A cylindrical guide member 20 for restricting the expansion of the diameter of the torsion coil spring 17 due to the torsional deformation is fitted inside the pipe 4. The length of the guide member 20 is set shorter than the entire length of the torsion coil spring 17. A damper 21 is interposed between the swing arm 1 and the vehicle body. Next, the operation will be described. When the rear wheel 3 is pushed up from the road surface, the swing arm 1 supporting the rear wheel 3 is displaced upward while rotating the pipe 4 with respect to the center bolt 5.
As a result, the stopper 18 fixed to the pipe 4 rotates while pressing one end of the torsion coil spring 17, and the diameter of the torsion coil spring 17 supported on the opposite end by the stopper 19 of the holder 16 is increased. Deforms torsionally.
The spring load due to this torsional deformation initially increases in proportion to the swing amount of the swing arm 1, but when the outer periphery of the torsion coil spring 17 comes into contact with the guide member 20, the torsion coil inside the guide member 20 is thereafter turned on. The deformation of the spring 17 is restricted, and only the diameter of the portion outside the guide member 20 increases. For this reason, from this point on, the rate of increase of the spring load with respect to the swing displacement of the swing arm 1 increases, and the spring load sharply increases with the displacement.
There is no risk that the 1 will bottom out. Note that the torsion coil spring 1
7 reduces the diameter and returns to the original state. When the angle of the arm 10 is changed by operating the turnbuckle 13, the holder 16 is rotationally displaced and the position of the torsion coil spring 17 is changed. As a result, the balance position of the swing angle of the swing arm 1 with respect to the vehicle body changes, and as a result, the vehicle height can be adjusted by operating the turnbuckle 13. That is, when the holder 16 is rotated while changing the angle of the arm 10, the torsion coil spring 17 is twisted, and the initial load changes. Thereby, the stopper 18
, The pipe 4 rotates about the ball bearing 9, the balance angle of the swing arm 1 changes, and the vehicle height changes. The angle of the arm 10 can be freely adjusted by operating the turnbuckle 13 and can be finely adjusted.
Adjusting the vehicle height is not only easy, but also accurate and fine-tuning. If the guide member 20 is formed so that its diameter changes stepwise or in a tapered manner, the rate of increase of the spring load can be gradually increased in accordance with the swing of the swing arm 1. Further, an auxiliary suspension spring 22 may be interposed in the damper. Further, the torsion coil spring 17 is interposed in the opposite direction, and both ends of the torsion coil spring 17 are
9, the torsion coil spring 17 is deformed in a direction to reduce the diameter in response to the upward swing of the swing arm 1, and the guide member 20 is disposed inside the torsion coil spring 17. It is also possible. As described above, according to the present invention, when the length adjusting means is operated to change the angle of the arm, the balance position of the torsion coil spring changes, and the swing angle of the swing arm with respect to the vehicle body is steplessly adjusted. The vehicle height can be adjusted easily, accurately and finely.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view of a swing arm fulcrum showing an embodiment of the present invention. FIG. 2 is a schematic side view of a vehicle body frame. FIG. 3 is a view taken in the direction of arrows AA in FIG. 1; FIG. 4 is a view taken in the direction of arrows BB. [Description of Signs] 1 swing arm 2 frame 4 pipe 17 torsion coil spring 20 guide member 21 damper

Continuation of the front page (56) References JP-A-58-97578 (JP, A) JP-A-59-171774 (JP, A) JP-A 57-22490 (JP, U) JP-A 60-18068 (JP, A) , U) JP-B-59-29467 (JP, B2) JP-B-57-49777 (JP, B2) JP-B-55-29300 (JP, B2) (58) Fields investigated (Int. Cl. ⁶ , DB) Name) B62K 25/10 F16F 1/12 F16F 7/00

Claims (1)

(57) [Claims] In a motorcycle with a rear wheel supported on a swing arm pivotally connected to the vehicle body and a damper interposed between the swing arm and the vehicle body, the base end of the swing arm is rotated on a swing axis supported by the vehicle body A torsion coil spring that urges the swing arm toward the extension side of the damper is wound around the swing shaft, and the base end of the arm is rotatably mounted on the swing shaft. And a free end of the arm connected to the vehicle body via a turnbuckle.