JPS6263232A - Shock absorber for saddle riding type vehicle such as motorcycle - Google Patents

Abstract

PURPOSE:To prevent an increase in width of a vehicle by providing a coiled spring forming a shock absorber, which is flat in a plan view, and disposing the coiled spring in such a manner that the minor axis of the coiled spring is extended along the width of the vehicle. CONSTITUTION:A pair of right and left shock absorbers 9 are extended between a car body frame 2 and a rear wheel 8. The shock absorber 9 comprises a hydraulic cylinder damping device 16 and a coiled spring 17 surrounding the damping device 17. The coiled spring 17 is formed like an ellipse flat in a plan view, and disposed in such a manner that the minor axis thereof is extended along the width of a vehicle. Accordingly, even if load to the coiled spring 17 is increased, the width of the vehicle can be kept from being increased.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a shock absorber for a saddle type vehicle such as a motorcycle.

(Prior Art) In a motorcycle as an example of the above-mentioned vehicle, wheels are normally supported on a body frame so as to be movable up and down, and a pair of left and right shock absorbers are placed between the body frame and the wheel side so as to sandwich the wheels from both sides. It will be erected in

Further, the above-mentioned shock absorber is composed of a damper that connects the vehicle body frame and the wheel side, and a coil spring that is wound around the damper and biases the damper in a direction to extend the damper.

(Problems to be Solved by the Invention) Recently, as vehicles have become larger, the load on the bipedal coil springs has also increased. In order to cope with this increase in load, the coil diameter and wire diameter are being increased, and as a result, the outer diameter of the spring tends to become larger.

However, the increase in the outer diameter of the spring causes an increase in the width of the vehicle, which forces the rider into an unnatural riding posture for motorcycles, which are straddle-type vehicles, and reduces ride comfort. There is a risk of causing Furthermore, an increase in the vehicle width dimension causes the mass of the vehicle to be dispersed in the vehicle width direction, which may increase the moment of inertia of the vehicle and reduce steering stability.

(Purpose of the Invention) This invention was made in view of the above-mentioned circumstances, and is designed to prevent the vehicle width dimension from increasing even when the load on the coil spring increases, and to prevent the vehicle body from increasing in the vehicle width direction. The purpose is to concentrate the mass of the vehicle body by preventing the mass of the vehicle from dispersing, and to maintain good handling stability.

(Structure of the Invention) The present invention for achieving the above object is characterized in that a coil spring constituting a shock absorber is formed into a flat shape in a plan view, and the short axis of the coil spring is oriented in the vehicle width direction. The point is that it is arranged so that it extends.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

1 to 5 show a first embodiment.

In FIG. 2, l is a motorcycle, and a front fork 3 is supported at the front end of a body frame 2 of the motorcycle. A front wheel 4 is supported at the lower end of this front fork 3.
A handle 5 is attached to the -L end of the front fork 3.

On the other hand, at the rear lower part of the bipedal vehicle body frame 2 is a rear arm 7.
is pivotally supported to be able to swing up and down, and a rear wheel 8 is supported at the swinging end of this rear arm 7.

A pair of left and right shock absorbers 9 are installed between the swing end of the rear arm 7 and the rear upper part of the vehicle body frame 2.

Further, an engine 10 is supported on the vehicle body frame 2, and the rear wheels 8 are driven by the bipedal engine 10 via a chain transmission means 11. 13 is a fuel tank, 14
is a sheet.

The shock absorber 9.9 is provided so as to sandwich the rear wheel 8 from the left and right sides, and buffers the impact received by the rear wheel 8 from the running surface so as not to transmit it to the vehicle body frame 2 side.

With reference to FIG. 1 and FIGS. 3 to 5, the buffer 9
will be explained in more detail.

The shock absorber 9 is composed of a hydraulic cylinder type damper 16 and a coil spring 17. The damper 16 has an upper end connected to the vehicle body frame 2 side, and a lower end connected to the rear arm 7 on the rear wheel 8 side. It is said to be stretchable. Further, the coil spring 17 is wound around the attenuator 16 and biases the attenuator 16 in a direction to expand it.

The damper 16 is a cylinder tube 18 filled with oil.
The cylinder tube 18 is connected to the rear arm 7, and a piston 19 is slidably fitted therein, and the end of a piston rod 20 connected to the piston 19 is connected to the vehicle body frame 2 side. Ru. Also,
The piston 19 is formed with a throttle oil passage 19a that communicates the two oil chambers 18a, 18a in the cylinder tube 18 partitioned by the piston 19.

When the rear wheel 8 vibrates up and down while driving, the piston 19 moves up and down in the cylinder tube 18, and at this time, a throttle oil passage 19a flows from one oil chamber 18a in the cylinder tube 18 to the other oil chamber 18a. Oil moves through the
The vibration of the rear wheel 8 is damped by the large flow resistance of the oil when it passes through the throttle oil passage 19a.

The coil spring 17 has a flat elliptical shape when viewed from above. Each coil spring 17 is arranged such that its short axis extends in the vehicle width direction. In this case, the coil spring 17 may have a rectangular shape instead of an ellipse shape.

Next, a structure for attaching the coil spring 17 to the attenuator 16 will be explained.

The piston rod 20 has a rod body 23 connected to the piston 19, and a lock nut 22 is screwed onto the protruding end of the rod body 23. Further, a rod head 24 is screwed to the protruding end of this rod body 23, and this rod head 24 is pivotally supported on the vehicle body frame 2.

A locking ring 26 having a flange 26a is fitted onto the end of the rod head 24 on the cylinder tube 18 side. 2
Reference numeral 7 denotes a spring receiving member, and this spring receiving member 27 supports one end of the coil spring 17 inserted therein. This spring receiver 27 has a bowl shape with an oval cross section as a whole,
A circular hole 28 is formed in its bottom. The spring receiver 27 has its circular hole 28 fitted onto the locking ring 26 and is locked to the flange 26a.

Further, an annular seat plate 29 that contacts the end surface of the coil spring 17 is fitted into the spring receiver 27 . This annular seat plate 29
The inner hole 29a is a circular hole, but the outer periphery of the spring receiver 2
It is assumed to be an ellipse that matches the cross-sectional shape of 7, and thereby,
The annular seat plate 29 is prevented from rotating relative to the spring receiver 27.

A locking protrusion 31 is formed on the cylinder tube 18 side surface of the rod head 24, and a notch 26b into which the locking protrusion 31 is fitted is formed in the locking ring 26. Further, the inner hole of the annular seat plate 29 has the notch 2
A locking piece 32 that fits into the spring receiver 6b is provided in a protruding manner, and by their mutual fitting, the upper end of the coil spring 17 that is fitted into the spring receiver 27 is prevented from rotating relative to the rod head 24. be done.

On the other hand, an outer flange 33 is provided at the end of the cylinder tube 18 on the side of the rear arm 7, and on this outer flange 33, another spring receiver 34 having the same structure as the spring receiver 27 marked with "-" is attached to the axis of the cylinder tube 18. It is supported so that it can rotate freely. Further, another annular seat plate 35 having substantially the same configuration as the annular seat plate 29 and without the locking piece 32 is fitted into the spring receiver 34 . Then, both ends of the coil spring 17 are fitted into the annular seat plates 29 and 35, respectively, and attached to the damper 16. A rubber cover 37 is fitted onto the rod body 23 and covers the lock nut 22.

By the way, when the rear wheel 8 vibrates up and down while driving and an external force is applied to the coil spring 17, the coil spring 17 will unwind due to its nature, that is, if it is right-handed, it will twist to the left. Both ends of the coil spring 17 try to deviate, but since the spring receiver 27 supported by the piston rod 20 is restricted from rotating, the end of the coil spring 17J-, which is fitted into the spring receiver 27, is is prevented from rotating. Therefore, this coil spring 17 can be held in a desired posture, and for example, the coil spring 17 rotates so that the long axis of the coil spring 17 is positioned in the vehicle width direction, thereby increasing the width dimension of the vehicle body. Such inconveniences are prevented.

In the case of two legs, since the lower end of the coil spring 17 is not restricted from rotating, it rotates somewhat due to the external force applied to the coil spring 17. Therefore, the spring receiver 34 supported on the cylinder tube 18 side may also have the same configuration as the spring receiver 27 described above to restrict its rotation. Further, the front fork 3 is configured with a shock absorber 9 at its upper and lower middle portions.

The above configuration may be applied to this buffer 9.

6 and 7 show a second embodiment. This embodiment has a different configuration from the previous embodiment, namely the attenuator 16.
The mounting structure of the coil spring 17 will be explained.

The surface of the rod head 24 on the cylinder tube 18 side is circular, and an annular stepped portion 38 is formed at the outer end in the radial direction of this surface. The coil spring 1 is attached to this annular stepped portion 38.
The upper end of 7 is fitted, and this upper end is connected to the piston rod 2.
It is attached to the 0 side.

Further, an engagement notch 39 is formed in the annular step portion 38, and one end piece of the coil spring 17 is bent, and this bent piece 17a is fitted into the two-legged engagement notch 39, whereby the rod Relative rotation of the upper end of the coil spring 17 with respect to the head 24 is prevented.

Although not shown, the attachment of the lower end of the coil spring 17 to the cylinder tube 18 side is also configured in the same manner as the two legs. In this case, the coil spring 17 against the engagement notch 39
The bent piece 17a may be inserted into only one of the upper and lower end pieces of the coil spring 17.

(Effects of the Invention) According to the present invention, the coil spring is formed into a flat shape in plan view, and the coil spring is arranged so that its short axis extends in the vehicle width direction. As shown by the two-dot chain line, the vehicle width can be made smaller compared to the circular shape. Therefore, even if the load on the coil spring increases as the vehicle becomes larger and it becomes necessary to increase the size of the coil spring, it is possible to prevent the vehicle width from increasing. Therefore, it is possible to avoid forcing the rider into an unnatural riding posture and ensure good riding comfort.

Furthermore, since an increase in the vehicle width dimension can be prevented, it is possible to concentrate the mass of the vehicle body by preventing the mass of the vehicle body from being dispersed in the vehicle width direction, and therefore, good steering stability can be maintained.

[Brief explanation of the drawing]

The figures show embodiments of the invention, and FIGS.
In the embodiment, Fig. 1 is a view taken along the line I-I in Fig. 2, Fig. 2 is an overall side view of the motorcycle, and Fig. 3 is a side sectional view of the shock absorber.
Fig. 4 is a view taken along the TV-TV line in Fig. 3, Fig. 5 is a developed side view of the coil spring mounting portion on the piston rod side, and Figs. 6 and 7 are the second embodiment. is a view corresponding to FIG. 4, and FIG. 7 is a view taken along the line ■-■ in FIG. 6. l...Motorcycle iK (vehicle), 2--heavy frame,
No. 8 - Rear wheel (wheel), 9 - Buffer, 16 - Attenuator,
17...Coil spring.

Claims (1)

[Claims] 1. A wheel is supported on the body frame so as to be movable up and down, and a shock absorber is installed between the body frame and the wheel side, and the upper end of this shock absorber is connected to the body frame side and the lower end is connected to the wheel side. In a straddle-type vehicle such as a motorcycle, which is composed of a telescoping attenuator and a coil spring that is wound around the attenuator and biases the attenuator in a direction to extend the attenuator, the coil spring is shown in a plan view. 1. A shock absorber for a straddle-type vehicle such as a motorcycle, characterized in that the coil spring is formed into a flat shape and arranged such that its short axis extends in the vehicle width direction.