JPS59128077A - Suspension system for front wheel of motorcycle - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a front wheel suspension system for a motorcycle in which a shock absorber is attached to a telescopic fork via a link mechanism.

In this type of front wheel suspension system, as illustrated in FIG. 2. The front wheel 3 is pivotally supported between the lower end portions of 2, and the inner cylinder 2 and the outer cylinder 1
A structure has been developed in which the relay rod 4 and the link lever 5t are connected by a rotatably combined link mechanism 6, and a shock absorber 2 is installed between the link lever 5 and the outer cylinder 1. (%Application No. 57-10459) According to this structure, the upper part of the inner cylinders 2, 2, which move up and down together with the front wheel 3, is slidingly guided by the lower part of the outer cylinder 1.1, so that it is particularly effective for push-cutting. Bearing part 8 that slides and guides the axle 3a of the front wheel 3, which is sometimes a load point, and the inner cylinder 2, which is applied to the outer cylinder IK.
The distance between them becomes large. Therefore, cylinder 2.
2 is compressed, a large bending moment acts on the outer cylinders 1, 1 and their bearings 8, resulting in K. Therefore, there are problems such as the need for rigidity and mechanical strength sufficient to withstand this large load. occurs.

The present invention was made based on these circumstances, and
The distance between the bearing part that slides and guides the sliding member and the front wheel axle that is the load point is always constant, and there is no large bending moment applied to this bearing part as in the prior art mentioned above, which improves strength. The object of the present invention is to provide a front wheel suspension system for a motorcycle, which is advantageous in that it can be made smaller and lighter, and also has improved operability.

That is, in order to achieve the above-mentioned object, the present invention provides a slide member that pivotally supports the front wheel and slidably penetrates the outer side of a pair of left and right guide tubes that extend along the vertical direction, and these slide members and the guide tube A rotary lever is pivotally attached to one of the tubes so as to be freely rotatable in the vertical direction, and the relative sliding displacement between the slide member and the guide tube is transmitted to the rotary lever on the other side. A rod member for rotating the lever is pivotally mounted, and a shock absorber is installed between the rotating lever and the guide tube.

A first embodiment of the present invention will be described below with reference to FIGS. 2 to 6.

In the figure, reference numeral 11 denotes a head arm which constitutes the frame of a motorcycle, and a telescope-type front fork 13 is attached to a steering shaft 12 through which the head and base 1lVc are inserted.

The front fork 13 has a pair of left and right guide tubes 14 and 15 along the vertical direction, and these guide tubes 1
The upper part of 4.15 is connected to the steering shaft 12 via an under bracket 16 and an under bracket 12.

A cylindrical slide member 18.19 is provided on the outer peripheral surface of the lower part of the guide tube 14.15 so as to be slidable in the axial direction. Stones/1' 20 and 20 are formed to prevent the slide members 18 and 19 from being pulled out. The slide members 18 and 19 are connected to the side tube 1 as shown in FIG.
An oil seal 22.22 and a bushing 23.23 that slides in contact with the guide tube 14 and 15 are installed in the openings at both ends of the through hole 21 through which the guide tube 4. 14 and 15 is filled with lubricating oil. And each slide member 18, 19 was provided protruding from the lower end front surface. Space part 2
The axle 27 of the front wheel 26 is installed between 5° and 25°.
The slide members 18, 19 are adapted to be slid up and down on the idle tube 14, 15 integrally with the front wheel 26.

On the outer surface of the upper end of each slide member 18.19, an intermediate portion of a link lever 28.28 serving as a rotation lever is pivotably supported in the vertical direction, and the id tube 1
One end of a beam relay rod 30, 30 as a rod member is pivotally supported on the platen h29, 29 provided on the rear surface of the upper part of 4.15. One end of the link levers 2B, 2B is rotatably connected to the other end of the relay rod 30.30 at the rear of the guide tube 14.15. Therefore, these link levers 28.28 and relay rods 30.30 constitute link mechanisms 31, 31 that connect the loose tube 14.15 and the slide member 18.19. When the sliding displacement occurs, one end of the link lever 28.28 beams the relay rod 3.
Since it is supported by 0.30, the slide member 18
．． The sliding displacement of 19 is transmitted to the link levers 28, 2B through the relay rod 30.30, so that the link lever 28.2B rotates counterclockwise and the other end is pushed upward. There is. The other end of this link lever 28.28 is led out to the front of the guide tube 14.15, and this other end and the under bracket 1
A buffer 3 is installed between the bracket 32 and 32 attached to 7.
3.33 has been constructed.

The distance between the pivot point A1 of the link lever 28 and the pivot points B, C, and K between the shock absorber 33 and the relay rod 30 on the link lever 28 is the same as that of the slide member 18.19. The expansion and contraction stroke of the shock absorber 33 is quadratic with respect to the sliding stroke.As shown in FIG. The stroke is set to gradually increase.

Next, the operation of the above configuration will be explained.

Assuming that the front wheel 26 receives an upward impact as shown in FIG. 5, the slide members 18 and 19 move upward while being guided by the idle tubes 14 and 15. Due to this movement, the cylinder frames 28, 28 rotate clockwise about the pivot point A, and the lower end of the shock absorber 33.33 is pushed up, so the sliding stroke of the slide member 18.19 is The signal is amplified in a quadratic manner by the mechanism 31.31 and transmitted to the buffer 33.33, thereby providing a problem-live buffering characteristic.

According to such a front wheel suspension system, the slide member 18.19 that moves together with the front wheel 26 is connected to the guide tube 14.15.
Since the slide members 18 and 19 are provided so as to be slidably penetrated therein, when the slide members 18 and 19 slide, they are entirely slidably guided along the sliding direction. Therefore, the slide member 1 in the ID tube 14.15
8. The bearing part that slides and guides the 19 and the front wheel 2 that is the load point
6 and the axle 22 is always constant, even if the sliding stroke of the slide members 18 and 19 changes, the load applied to the bearing portion does not change, and therefore the tilting stroke of the slide members 18 and 19 changes. Operability is improved across the entire range.

In addition, the bending moment applied to the sliding parts of the slide members 18 and 19 is small, and therefore the slide members 18 and 19
* There is no need to significantly increase the rigidity or mechanical strength of the 15' and 14° 15' side tubes, making it possible to reduce the size and weight.

Note that the present invention is not limited to the above-described M1 embodiment, and a second embodiment of the present invention is shown in FIGS. 7 and 8. In this second embodiment, one end of the relay rod 41, 41 is attached to the slide member 18, 19, and one end of the relay rod 41 is attached to the guide tube 1.
4.15 bracket 29.29 has link lever 42
42, and the other ends of the relay rods 41, 41 and link levers 42, 42 are connected to each other in front of the guide tube 14, 15, and also to the front wheel 26.
By rotatably connecting above the syringe mechanism 4. ．． 9.43, the link lever 42,
The connecting arm 44 that connects the middle part of 429 to the left and right and the an/(
'One shock absorber 33 is installed between the bracket 45 fixed to the bracket 16 and located approximately on the center line of the grass. According to this configuration, the left and right link levers 42.4
Since the two are connected by the connecting arm 44, one shock absorber 33 can be used for the left side.

Further, a third embodiment of the present invention is shown in FIGS. 9 and 10. In this third embodiment, the slide member 51.5
2 extends above the front wheel 26, and connects the upper ends with a stabilizer rope 53 to connect both slide members 51.
．． 52 are linked together. An intermediate portion of a link lever 55 is pivotally supported on a support portion 54 erected in the center of the upper surface of the stabilizer pipe 53, and the under bracket 12
One end of a relay rod 56 is pivotally supported on the rear surface of the
The other ends of the link lever 55 and the relay rod 56 are rotatably supported at the rear between the guide tubes -14i15 to form a link mechanism 52. One end of the link lever 55 is guided forward between the side tubes 14 and 15, and is located approximately on the center line of the vehicle body between this one end and a bracket 58 fixed to the opening bracket 16. One buffer 33 is installed. Note that a front fender 59 is attached to the stabilizer bar 53.

According to the third embodiment, the left and right slide members 5
1.52 are interlocked by the stabilizer tube 53, so only one link mechanism 57 and one shock absorber 33 are required, reducing the number of parts.In addition, the stabilizer tube 53 increases the torsional rigidity of the guide tube 14 and 15. Tomo K
There is an advantage that the stabilizer strip 53 can be used as a mounting part for the front fender 59.

According to the present invention described in detail above, since the slide member that pivotally supports the front shaft is provided on the outside of the guide tube so as to be slidable in the axial direction, the bearing portion for slidingly guiding the slide member in the guide tube is Since the distance between the load point and the front wheel's rabbit axle is always constant, even when the slide 9 member slides, the load applied to the bearing part does not change, so the load applied to the bearing part does not change over the entire sliding stroke of the slide member. Operability is improved throughout. Moreover, since it is advantageous in terms of strength, there is no need to significantly increase the rigidity or mechanical strength of the guide tube, and there is an advantage that the guide tube can be made smaller and lighter.

[Brief explanation of drawings]

FIG. 1 is a partially sectional side view of the prior art, FIGS. 2 to 6 show a first embodiment of the present invention, FIG. 2 is a side view, FIG. 3 is a front view, and FIG. The figure is a cross-sectional view of the slide member.
Fig. 5 is an operation explanatory diagram, Fig. 6 is a characteristic diagram showing buffer characteristics,
7 and 8 show a second embodiment of the present invention, and FIG.
The figure is a side view, FIG. 8 is a front view, FIG. 9 and M2O illustrate a third embodiment of the present invention, M9 is a side view, and FIG. 1θ is a front view. ! 4, 15...Guide tube, 1B, 19°51
．． 52...Slide member, 26...Front wheel, 28°4
2.55...Rotating lever (link lever), SO. 41.56...Rod member (relay rod), 33.
・Buffer. Applicant's agent Patent attorney Takehiko Suzue Figure 2 Figure 3 Figure 4tj! j

Claims (1)

[Claims] A pair of left and right slide members along the vertical direction are provided on the outside of the ID tube so as to be slidable in the axial direction IIc, and the front wheel is pivotally supported between these slide members. A rotary lever is pivotally attached to one side so as to be freely rotatable in the vertical direction, and a slide member is attached to the other side to transmit the relative sliding displacement with the id tube to the rotary lever to rotate the rotary lever. 1. A front wheel suspension system for a motorcycle, characterized in that a rod member to be moved is pivotally mounted, and a shock absorber is installed between a rotary lever and an idle tube.