JPH01204879A - Front-wheel suspension system for saddle type vehicle - Google Patents

Abstract

PURPOSE:To secure such a suspension arm hat is high in rigidity by forming the tip side of an arm pipe consisting of a section polygonal light metal into a taper form, while installing an axle side end in this tip part and a pivot part in a base end respectively, and using these parts as the suspension arm. CONSTITUTION:In this saddle type four-wheel vehicle, both upper and lower suspension arms 16, 17 of a double-wishbone type suspension are attached to a bridge tube 5 in a body frame 1 and the lower side of a front tube 7 via a bracket 18, supporting a front wheel. In this case, the upper suspension 16 is formed with an arm pipe 19 composed of an aluminum tube formed in a section quadrilateral, and this arm pipe 19 forms such a notch 22a as dotted lines in the axial direction, and it is formed into a taper form as fused as a continuous line.

Description

[Detailed description of the invention] a. Industrial application field The present invention relates to a front wheel suspension system for a saddle type vehicle.

b. Conventional technology Since the purpose of a vehicle used for traveling on rough terrain is to allow passengers to drive stably, a front-wheel vehicle 101 and a rear-wheel vehicle are mounted on a body frame 100 shown in FIGS. 6 and 7. A so-called straddle-type four-wheeled vehicle was developed that had two wheels each equipped with 102.

This type of straddle-type four-wheel vehicle has a wishbone type suspension 1 on the front wheel to improve running performance on rough terrain.
There is one that uses 03.

This suspension 103 is a thick up suspension arm 105 that suspends upper and lower suspension arms 105, which are composed of two arm pipes whose tips are commonly connected and a pivot boss 104 is welded to the rear end. It is composed of a saucer 106.

Problems to be Solved by the C0 Invention However, the suspension arms 105 are usually made of steel and are therefore heavy, and two suspension arms 105 are required, resulting in an increase in weight. .

Furthermore, there is known a prior art (Japanese Patent Application Laid-open No. 58-67507) in which the upper suspension arm of a double-wiss-off suspension is constructed of one plate.

However, this prior art involved welding U-shaped frames facing each other, resulting in long welding locations and poor workability.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a front wheel suspension system for a straddle-type vehicle that solves the above-mentioned problems of the prior art, maintains the necessary rigidity, is lightweight, and is inexpensive.

d. Means for Solving the Problems In order to solve the above-mentioned problems, the present invention forms the arm pipe of the suspension arm using a lightweight metal having a polygonal cross section, and the tip of the arm pipe has an axial direction. At the same time, a notch is formed, and the cut surface of the notch is explosively bonded to form a distal end thinner than the proximal end, and a pivot part is provided at the proximal end, and an axle side end is attached to the distal end. A front wheel suspension system for a straddle-type vehicle is characterized in that a suspension arm is constructed by providing a section.

e. Since the working arm pipe can be reduced to one, the number of parts of the suspension arm can be reduced and the weight can be reduced.

f. Example An example of the present invention will be described below with reference to the drawings.

In Figures 1 and 2, 1 indicates the front wheel 2 and the rear wheel 3.
This is a body frame for a straddle-type four-wheeled vehicle with two wheels each.

This consists of one tank rail tube 3 whose tip end is connected to a steering head 2a that supports a steering shaft 2, a pair of side members 4 connected to both sides of the tank rail tube 3 to form an engine mounting section, and a side member 4 connected to both sides of the tank rail tube 3 to form an engine mounting section. The seat rail 5 extends behind the member 4 and forms a seat arrangement section.

Each of the side members 4 extends diagonally downward from the front sides of the tank rail tube 3 so as to spread to both sides, and has a front end curved backward to form a front part 6.
A front tube 7 formed with a
A down tube 8 connected to the tip of the front tube 7, a lower tube 9 formed integrally with the down tube 8, and a rear end of the tank rail tube 3 curved upward from the rear end of the lower tube 9. It is made up of a tube connected to a section.

Down tube 8, lower tube 9 and rear tube 10
is formed by bending a single pipe, and a bracket 13 is provided to attach a swing arm 12 that supports a rear axle 11 to the bent portion of the lower tube 9 and rear tube IO. An engine 14 is mounted in a space formed by the side member 4.

As the engine 14, for example, an engine with an automatic transmission or the like can be installed.

15 is the tip of the front tube 7 and the down tube 8
This is a bridge tube connected in the middle of the front tube 7, and is provided substantially parallel to the lower side of the front tube 7.

Brackets 18 are provided on the lower sides of the bridge tube 15 and the front tube 7, respectively, for attaching the upper and lower suspension arms 16 and 17 of the double-wissocheborn type suspension. There is one bracket 18 on the bridge tube 15,
The front tube 7 is provided at two locations. The upper suspension arm 16 uses an aluminum tube with a square cross section as shown in FIGS. 3 and 4 for the arm pipe 19 that serves as the suspension arm body, and one end of this arm pipe 19 serves as a pivot shaft. Pivot boss 20. An end boss 21 that supports the axle is attached to the other end. The arm pipe 19 is formed so that the end on the side where the end boss 21 is attached is narrow and curved. This is done by forming a cutout 22a in the axial direction of the arm pipe 19 as shown by the dotted line in the figure, and then explosively attaching the cutout 22a as shown in 1122.

On the other hand, the lower suspension arm 17 is made up of two arm pipes 23+ and 23g, which are attached together with an end boss 24 at the tips thereof, and is rotatably supported by the bracket 18 by a pivot boss 25 at the rear end. The lower end of the shock absorber 26 is attached to the lower suspension arm 17. The shock absorber 26 has its upper end supported by a bracket 27 attached to the upper side of the front tube 7.

Note that the arm pipe of the lower suspension arm 17 may also be formed from a single aluminum tube, similarly to the upper suspension arm 16.

According to the above configuration, the upper suspension arm 16
Since it is lightweight, it is possible to reduce the weight of the vehicle and obtain sufficient rigidity.

Further, the wheels can be suspended not only by the double wishbone type but also by the wishbone type as shown in FIG. 5 using one suspension arm 28 and a thick absorber (not shown).

g. Effects of the Invention As described above, according to the front wheel suspension system for a straddle-type vehicle according to the present invention, the arm pipe of the suspension arm is formed using a lightweight metal having a polygonal cross section, and the tip of the arm pipe is A notch in the axial direction is formed in the part, and the cut surface of the notch is welded to form a distal end thinner than the proximal end. Since the suspension arm is constructed by providing an axle-side end portion on the axle side end portion, a suspension arm having sufficient rigidity can be provided with one arm pipe. Therefore, the number of parts can be reduced, and the overall weight can be reduced.

[Brief explanation of the drawing]

1 and 2 conceptually show an embodiment of the front wheel suspension system for a straddle-type vehicle according to the present invention. FIG. 1 is a side view showing the entire vehicle body, and FIG. FIG. FIG. 3 is a conceptual diagram showing an upper suspension arm, FIG. 4 is a sectional view taken along line A-A&I in FIG. 3, FIG. 5 is a plan view showing a front wheel suspension system according to another embodiment of the present invention, and FIG. FIG. 7 is a perspective view showing a straddle-type four-wheeled vehicle, and is a front view showing a conventional front wheel suspension system. 1...Vehicle frame, 7...Front tube,
15... Bridge tube, 16... Upper suspension arm, 17...
Lower suspension vent silane arm, 18...bracket,
19... Arm pipe, 22a... Notch, 2
6 river shock absorber. Patent applicant: Suzuki Motor Co., Ltd. Figure 3 Figure 5

Claims (1)

[Claims] An arm pipe of a suspension arm is formed using a lightweight metal having a polygonal cross section, an axial notch is formed at the tip of the arm pipe, and the cut surface of the notch is welded. A front wheel suspension for a straddle-type vehicle, characterized in that a distal end portion is formed thinner than a base end portion, a pivot portion is provided at the base end portion, and an axle side end portion is provided at the distal end portion to constitute a suspension arm. Device.