JPS61125979A - Swing type rear arm device for 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 [Technical Field of the Invention] The present invention relates to a swing type rear arm device for supporting a rear wheel of a motorcycle.

(Technical background of the invention and its problems) There is a desire for this type of rear arm to be as light as possible in order to improve the road surface followability of the rear wheels. For this reason, the present applicant has already filed the patent application No. 58-320.
As seen in No. 31, the rear arm is formed into a generally triangular shape when viewed from the side, making it lightweight and at the same time ensuring rigidity against torsion. That is, the rear arm usually has a front end pivotally supported by the vehicle body, and a pair of left and right arm sections supporting the axle of the rear wheels at the rear end.While driving, the front end of the rear arm supports the vehicle body. A twisting force is applied around the longitudinal axis. For this reason, in the rear arm of the prior art, an auxiliary arm part is joined to the rear end of the arm part, and the auxiliary arm part extends diagonally upward forward and connects the arm parts immediately before the rear wheel. The structure is such that a front panel is attached between the upper part of the front end, which is the extending end of the rear arm, and the front end of the arm. The torsional rigidity is increased.

Incidentally, recent motorcycles use a suspension system that connects a rear arm and a hydraulic shock absorber via a link mechanism in order to obtain progressive shock absorbing characteristics. In this case, in the case where the link mechanism is located below the rear arm, the hydraulic allergen is placed vertically in the vertical direction just between the front end pivot of the rear arm and the rear wheel. If adopted, the hydraulic shock absorber will just pass through the front panel. Therefore, the hole is formed in a portion of the rear arm that has a particularly large effect on torsional rigidity, so sufficient consideration must be given to ensuring this torsional rigidity.

[Purpose of the invention]

The present invention was made based on these circumstances, and
An object of the present invention is to provide a swing type rear arm device for a motorcycle that can improve the torsional rigidity of a rear arm even when a hydraulic shock absorber passes through the rear arm.

[Summary of the invention]

That is, in order to achieve the above object, the present invention provides a pair of left and right reinforcing arms between the front end pivot portion of the arm portion and the front end upper portion of the auxiliary arm portion, and these reinforcing arms are installed between the front end upper portion of the auxiliary arm portion. The reinforcing arms are arranged so that they are inclined in an expanded shape so that the width of the separation increases as one moves toward the front end of the arm, and a hydraulic shock absorber is inserted and placed in the expanded part where the width of the reinforcement arm increases. Features.

[Embodiments of the invention]

The present invention will be explained below based on an embodiment shown in the drawings.

1 in Fig. 5 is an aluminum alloy frame that constitutes the vehicle body, and the frame 1 in this embodiment includes a main frame structure 3 having a monocoque structure that supports a head vibrator 2, and a main frame structure 3 that is branched from this main frame structure 3. It is composed of left and right seat rails 4. The main frame structure 3 is bifurcated behind the head vibrator 2 and extends rearward, and an engine 6 is suspended and supported by these left and right branch portions 5. Further, a rear arm bracket 1 is welded to the rear end of the branch portion 5, and a rear arm 8 according to the present invention is pivotally supported to the rear arm bracket 7 via a pivot shaft 9. Regarding this rear arm 8,
To explain with reference to the figures to FIG. 4, 10a in the figure,
Reference numeral 10b denotes a pair of left and right arm portions, which are shaped like square pipes with a square cross section. A pivot vibe 11 is welded between the front ends of the arm portions 10a and 10b, and the pivot shaft 9 is inserted through the pivot vibe 11.

Further, an axle 13 of a rear wheel 12 is supported between the rear end portions of the arm portions 10a and 10b. Arm part io
A, An auxiliary arm portion 14 extending obliquely upward and forward is joined to the upper surface of the rear end portion of iob. The auxiliary arm part 14 is a square pipe bent into a substantially U-shape, and both ends of the auxiliary arm part 14 are welded to the rear end parts of the arm parts 10a and 10b, and the front end upper part 14a, which is an extended end, is attached to the rear end of the auxiliary arm part 14. Located just in front of the ring 12, at this position the arm portion 10a.

10b are interconnected. Arm parts 10a, 10
A reinforcing bottom plate 16 is welded to the lower surface of the front end of b, spanning the pivot vibrator 11, and between the rear part of this reinforcing bottom plate 16 and the front end upper part 14a of the auxiliary arm part 14, the rear wheel 1
A reinforcing plate 17 covering the area immediately in front of 2 is welded.

Note that a stay 18 is installed between the upper surfaces of the arm portions 10a and 10b and both side portions 14b of the auxiliary arm portion 14.

The front end upper part 14a of the auxiliary arm part 14 and this front end upper part 14
A pair of left and right reinforcing arms 19a each having a rectangular pipe shape are connected to the pivoting vibrator 11 located at the lower front side of point a.
19b is installed. Reinforcement arm 19a.

19b is arranged to be inclined in an expanded shape so that the separation width gradually increases as it progresses from the auxiliary arm section 14 side to the pivot vibrator 11 side, and the end thereof on the pivot vibrator 11 side
The front end portions a and 10b are butt-welded to the outer circumferential surface of the pivot vibrator 11. Therefore, the reinforcing arms 19a and 19b have a substantially V-shape when viewed from the front. Furthermore, between the front ends of the arm parts 10a and 10b and the front end upper part 14a of the auxiliary arm part 14,
A front panel 22 made of aluminum steel plate is attached. The front panel 22 of this embodiment includes left and right arm portions 10a,
10b, left and right reinforcement panels 23a, 23b that laterally cover the area surrounded by the reinforcement arms 19a, 19b and both sides of the front end upper part 14a, and upper and lower reinforcement panels 2 that cover between the front surfaces of the reinforcement arms 19a, 19b.
4a and 24b, and by attaching this front panel 22, the entire rear arm 8 is framed in a substantially triangular shape when viewed from the side, and a hollow box portion 25 is formed within the front end of the rear arm 8. There is. Further, a guide pipe 20 made of an aluminum steel plate is vertically inserted through the expanded portion of the reinforcing arms 19a, 19b where the width of separation is widened.

The upper end of the guide vibe 20 has reinforcing arms 19a, 1
9b and the upper and lower reinforcing panels 24a, 24b and are welded together, and the lower end is connected to the bottom plate 16.
It is welded to the opening periphery of an insertion hole 21 opened in , and penetrates inside the box portion 25 at the front end of the rear arm 8 .

On the other hand, near the front end pivot portion of the rear arm 8, one hydraulic Il shocker 26 is disposed vertically in the vertical direction.

The hydraulic shock absorber 26 is attached to the rear arm 8 as shown in FIG.
The upper end of the guide pipe 20 is connected to the seat rail 4, and the lower end thereof is connected to the rear arm 8 via a link depression 27.

As shown in FIG. 7, the link-like structure 27 is formed by rotatably combining a relay arm 28 and left and right tension rods 29, 29, and is located below the front end pivot portion of the rear arm 8.

That is, one end of the relay arm 28 is connected to the cross member 30 connecting the rear arm brackets 7 and 7, and
One end of the tension rod 29.29 is attached to the rear arm 8.
The middle part of the relay arm 28 is pivotally supported between the other ends of the tension rods 29 and 29, and the other ends of the relay arm 28 are Hydraulic shock absorber 2 at the end
The lower ends of 6 are connected. Therefore, the swing stroke of the rear arm 8 is successively increased by the relay rod 28 and the tension rod 29, and is transmitted to the hydraulic pressure unit 26.

According to the rear arm 8 having such a configuration, when a vertical load is applied to the rear end portions of the arm portions 10a and 10b through the axle 13 as indicated by the arrows in FIG. A twisting force is applied to the front end, which is the end, to twist the vehicle body around the longitudinal axis 01-01.

However, in the above configuration, the arm portion 10a.

Since the reinforcing arms 19a and 19b, which expand in a V-shape when viewed from the front, are installed at the rl between the front end of the auxiliary arm 10b and the front end upper part 14a of the auxiliary arm 14, the box part 2
A substantially triangular frame, which is advantageous in terms of strength, is formed on the front surface of 5. Therefore, since the reinforcing arms 19a and 19b resist torsion, the rear arm 8 has high rigidity against torsion, even though the hydraulic shock absorber 26 penetrates the front panel 22, which greatly affects torsional rigidity, and hydraulic pressure! 1l
It is possible to prevent a decrease in rigidity due to penetration of the II vessel 26.

Furthermore, in this embodiment, a guide vibe 20 made of aluminum steel plate is arranged in the part where the hydraulic shock absorber 26 penetrates, and this guide vibe 20 is welded to the reinforcing arms 19a, 19b, the reinforcing panels 24a, 24b, and the bottom plate 1G. Therefore, the guide vibe 20 bears part of the torsional force applied to the rear arm 8, and the rear arm 8 becomes more rigid against torsion.

Further, by arranging the reinforcing pipes 19a and 19b in an expanded shape, there is an advantage that a sufficient space for passing the hydraulic shock absorber 26 can be secured on the expanded side.

In the above embodiment, a guide vibe was provided at the part of the rear arm that penetrates the hydraulic shock absorber, but this guide vibe is not necessarily necessary, and the frame structure is not limited to the above embodiment. It may be a pipe frame.

〔Effect of the invention〕

According to the present invention described in detail above, a reinforcing arm that expands in a . A substantially triangular frame, which is advantageous in terms of strength, is formed on the front surface of the rear arm to which moderate torsional force is applied, and this reinforcing arm resists torsion. Therefore, even though the hydraulic shock absorber penetrates the front panel of the rear arm, which greatly affects torsional rigidity,
This has the advantage of ensuring sufficient torsional rigidity of the rear arm.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention; FIG. 1 is a perspective view of the rear arm, FIG. 2 is a side view of the rear arm, FIG. 3 is a view taken from the direction of the arrow in FIG. 2, and FIG. 5 is a side view of the motorcycle, FIG. 6 is a sectional view of the suspension portion of the rear arm, and FIG. 7 is a sectional view of the link mechanism. 1... Vehicle body (frame), 8... Rear arm, 10
a. 10b...Arm part, 12...Rear wheel, 13...Axle, 14...Auxiliary arm part, 19a, 19b...
- Reinforcement arm, 22...Front panel, 26...Hydraulic shock absorber. Applicant's agent Patent attorney Takehiko Suzue Figure 1

Claims (1)

[Claims] A pair of left and right arms whose front ends are pivotably supported relative to the vehicle body and whose rear ends support the axles of the rear wheels are provided with an arm extending diagonally forward from the rear end of the arm. An auxiliary arm part that extends upward and connects the arm parts in front of the rear wheel is joined, and between the upper part of the front end which is the extended end of the auxiliary arm part and the front end pivot of the arm part. In a swing type rear arm device in which a rear arm having a substantially triangular shape in side view is constructed by constructing a front panel, and a hydraulic shock absorber vertically placed vertically passes through the front panel of the rear arm, the front end of the arm portion is A pair of left and right reinforcing arms is installed between the pivot portion and the upper front end of the auxiliary arm portion, and these reinforcing arms are arranged such that the distance between them increases as they move from the upper portion of the front end of the auxiliary arm portion toward the front end of the arm portion. A swing type rear arm device for a motorcycle, characterized in that the hydraulic shock absorber is inserted through the widened portion of the reinforcing arms, and the hydraulic shock absorber is inserted into the widened portion where the width of separation between the reinforcing arms is widened.