JPS6192985A - 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] (Industrial application field) The present invention relates to a front wheel suspension system for a motorcycle.

(Prior art) Front wheel suspension systems for motorcycles are generally divided into two types: a telescopic system with sliding inner and outer cylinders, and a link system.
Each structure has a length of 4 centimeters, but currently the telescopic system, which has a linear trajectory of the axle and has a sufficient stroke, is the mainstream.

In some car models, a link system with good operability, such as a leading type, is adopted, but this is limited to certain car models because the trajectory of the axle is arcuate and the stroke cannot be adjusted. The reality is that there are.

British Patent No. 21,494 discloses a garter fork force type front wheel suspension for a motorcycle having two converging swing arms, and British Patent No. 526,11
No. 6 discloses a 1j-wheel suspension system for an aircraft using a parallelogram link system having two swing arms.

(Problem to be solved by the invention) However, in the garter fork system, the trajectory of the width axis draws a circular arc, while in the parallelogram link system, the trajectory of the axle is linear up to a certain range, but beyond that. Draw a fairly arc-shaped trajectory 1. Mau.

Therefore, the object of the present invention is to provide a quadrilateral link system with good operability in order to transmit force in the rotational direction basically in accordance with the content of Scott Russell's theorem in mechanics, but with a sufficient stroke. To provide a front wheel suspension system for a motorcycle 11 which can simultaneously obtain an arbitrary axle travel path and also achieve effective use of space.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a motorcycle with:
An upper fork (3) rotatably supported at the upper part by a head pipe (11) and a lower fork (6) with a wheel (8) pivotally supported at the front part are connected to a front and rear swinging arm (4),
(5) are connected to form a quadrilateral link in side view, and are provided with springing means (7) that acts on the quadrilateral link, as well as front and rear swing arms (4).

(5) are arranged so as to converge downward, and the rear swing arm (5) is arranged almost vertically in side view.

(Function) In particular, the upper fork (3), the lower fork (6), and the front and rear swing arms (4), (5) form a quadrilateral link in side view, and the front and rear swing arms (4), (5)
The axle (6) is arranged so that it converges downward, so the axle (6)
The locus of 5) can be set arbitrarily, and a sufficient stroke can be obtained by moving the instantaneous center (0) of the actuation during the stroke.

The rear swing arm (5) is arranged almost vertically when viewed from the side, making effective use of the space between the down tube (12) connected to the head pipe (11) and the upper fork (3). It becomes a structure.

(Example) Examples will be described below based on the accompanying drawings.

Figure 1 is a side view of the motorcycle, and Figure 2 is a perspective view showing the link structure of the front wheel suspension system.
) A head pipe (11) that tilts backward is fixedly installed on the front part, and a handle stem shaft (not shown) is rotatably inserted and supported in the head pipe (11). Top bridge (35) and bottom bridge (36)
) is fixed at the middle part, and a bar handle (2) is fixed on the top bridge (35).

A pair of left and right upper arms (31), (31) are located at both ends of the top bridge (35) and bottom bridge (38).
is fixed at the top, which allows the upper fork (3)
is configured. The left and right upper arms (31) forming this upper fork (3) have front and rear swinging arms (4) at pivot points (41) and (51) at the lower ends and middle portions thereof.

(5) are respectively pivotally supported, such swinging arms (4).

At the lower end of (5), a lower arm (61) is pivoted at pivot points (42) and (52) at the intermediate portion and rear end, respectively.

An axle (65) is installed between the front ends of the left and right lower arms (81) and (61), and a connecting shaft (66) is installed between the rear ends, thereby forming a lower fork (6).

The lower part of the front swing arm (4) and the middle part of the upper arm (31) are equipped with a shock absorber (7) that serves as an elastic means, that is, a spring (71) coaxially attached and a shock absorber 8. (72) is constructed, and a wheel (8) forming a front wheel is attached to the intermediate portion -t= of the axle (65).

In this way, the front wheel suspension system includes an upper fork (3), front and rear swing arms (4), (5), and a lower fork (6).
) constitute a quadrilateral link in side view.

In the above, as shown in FIG. 3, the front and rear swing arms (4) and (5) are arranged so as to converge downward,
That is, the upper arm (31) and the lower arm (81)
Each pivot point (41) of the front swing arm (4)
, (42) and the line segment (12) that also connects the pivot points (51) and (52) of the rear swing arm (5) intersect below. As a result, the line segment (intersection 1
) and the line segment (intersection 2) (0) is the lower arm (61
) will be located below the latter half (63) of the second half (63).

Here, the front swing arm (0 is the rear swing arm (5)
), so that the quadrilateral link has a substantially rhombic shape that is elongated in the vertical direction, and a buffer (7) is disposed in the longitudinal direction within this rhombic link.

Then, the angle formed by the upper part of the line segment (Kou 3) connecting the axle shaft (65) support point of the lower arm (61) and the pivot point (42) and the lower part of the line segment (Text 1) is the third order. minute m
(14) are arranged substantially perpendicular to the stroke path (L) of the axle (65), and the pivot points (42) and (52
) The axle (65) is arranged within the angular range formed by the L side of the line segment (intersection 5) connecting the lines (intersection 5) and the lower side of the line segment (U+).

In addition, the line segment (intersection 3) is arranged almost horizontally, that is, the +
While the initial setting is made by arranging the iii.
The rear half (63) is formed by slanting it backwards.

Further, both swing arms (4), (5) and a lower arm (81) are arranged on the rear side of the upper arm (31), and the axis (S) of the steering stem shaft supported within the head pipe (11) is arranged. in such a way that the axis (S) intersects the quadrilateral link, that is, the front and rear swinging arms (4), (5)
Arrange and configure so that they intersect.

Further, the rear swing arm (5) is arranged almost vertically.

In this way, the front and rear swing arms (4) and (5) constituting the quadrilateral link in side view are arranged so as to converge downward, so that the axle (65) (; during the downward stroke It is possible to change the instantaneous center (0) of the front wheel suspension at , thereby obtaining a sufficient stroke of the axle (65), as well as adjusting the length of the swinging arms (4), (5), the angle of convergence, etc. The trajectory of the axle (65) can be arbitrarily set based on the following.

Moreover, as in the example, the bisector of the angle formed by the lower part of the line segment (Ill) and one side of the line segment (text 1) (text 4)
) is arranged almost perpendicularly to the travel path (L) of the axle (65), and the line segment (15) is located below the line segment (see 1).
If the axle (85) is placed within the angular range formed by the upper part of the axle and the upper part of the axle, a linear stroke path (L) of the axle (65) can be obtained as shown in FIG.

Since the rear swing arm (5) is arranged almost vertically when viewed from the side, the down tube (5), which is a frame structural member connected to the head pipe (11) and extending downward and backward, as shown in Fig. 12) and the upper fork (3) in front of it. Therefore, the space between the upper fork (3) and the down tube (12) can be effectively utilized to arrange the swing arm (5).

1. Front swing arm (4) and lower fork (
6) is also placed on the rear side of the upper fork (3), so the quadrilateral link is placed close to the frame (1), resulting in a good weight balance of the vehicle body.

Furthermore, in the embodiment, the front and rear swing arms (
Focus on 4) and (5)! ! (S) are arranged to intersect, so the moment of inertia of the quadrilateral link with respect to the steering stem axis is reduced.

Also, as in the example, the line segment (hair 3), that is, the lower arm (6
If the front half (B2) of 1) is arranged almost horizontally, the vehicle height can be made different, and the arrangement structure is excellent in absorbing uneven road surfaces. 5),
That is, if the rear half (63) of the lower arm (61) is bent upwardly, it is advantageous in terms of ground hit prevention 11 of the lower arm (63).

(Effects of the Invention) As described above, according to the front wheel suspension system for a motorcycle of the present invention, a sufficient stroke and an arbitrary travel path of the axle can be obtained at the same time while using the quadrilateral link system with good operability. This also makes effective use of space possible.

[Brief explanation of drawings]

FIG. 1 is a side view of the motorcycle, FIG. 2 is a perspective view showing the link structure of the front wheel suspension, and FIG. 3 is a schematic side view showing the arrangement and operation thereof. In the drawings, (1) is the frame, (11) is the head pipe, (12) is the down tube, (3) is the upper fork, (31) is the upper arm, (35), (3)
B) is the bridge, (4) and (5) are the swing arms, (4
1), (42). (51), (52) are pivot points, (8) is lower fork, (61) is lower arm, (65) is axle, (66)
is the connecting shaft, (7) is the shock absorber, (8) is the wheel, (cross 1)
...(Intersection 5) is the line segment, (0) is the instantaneous center, (L) is the stroke path of the axle, and (S) is the axis of the handle stem shaft. Patent Applicant Ki Ill Giken Togyo Co., Ltd. Agent Patent Attorney 2 1) Yu-bu Kai Patent Attorney Dai
Kuni Hashi Onma Patent Attorney Elementary School 1i
Same as right Patent attorney 1: No 1)
great clarity

Claims (1)

[Claims] An upper fork rotatably supported at the upper part of the head pipe and a lower fork with a wheel pivotally supported at the front are connected by front and rear swinging arms to form a quadrilateral link in side view. An automatic motor vehicle comprising a resilient means acting on the quadrilateral link, front and rear swinging arms arranged so as to converge downward, and the rear swinging arm arranged almost vertically when viewed from the side. Front wheel suspension system for motorcycles.