JPH01106790A - Mounting structure of shock absorber of frame for motorcycle - Google Patents

Abstract

PURPOSE: To guarantee a frame for strength and to make the frame lightweight by connecting the upper end portions of a pair of seat pillar tubes to both sides of the rear end portion of a main pipe, pivotally supporting the upper end portions to portions near a connection at the upper end of a shock absorber, and connecting the other end to a rear arm located below the tubes. CONSTITUTION: A shock absorber 3 is connected by a pin 5 at its lower end to a supporting part 4 provided at the top of a rear arm, and is connected by a pin 7 at its upper end to a portion near the rear end portion of a main pipe 1b, i.e., inside a connecting member 6. The connecting member 6 comprises a cylinder part 6b, into which the rear end portion of a pipe 1 is inserted for connection, and a connection 6b integrally formed with the cylinder part 6a, and is substantially integrated with the main pipe 1b. The front end portion 1c1 of a seat rail 1c and a seat pillar tube 1d1 are connected to both sides of the connecting member 6. The shock absorber 3 is thus exposed to the outside and cooled by running wind, and since the load applied to the shock absorber 3 is received by the portion near the rear end portion of the main pipe 1b and by the lower part of the seat pillar tube 1d1 as tensile load, a frame is guaranteed for strength.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a structure for mounting a shock absorber on a motorcycle frame equipped with a mono-20 suspension.

[Conventional technology]

Conventionally, as this type of frame for a motorcycle, there is a frame proposed by the applicant in Japanese Utility Model Application Publication No. 52-26341.

Most of the shock absorber is housed inside the main pipe, which has a vertically elongated oval shape on the steering head pipe side, and the front end of the shock absorber is journalled on the oval part of the main pipe, that is, the part close to the steering head pipe. It is. On the other hand, the seat pillar tube extends diagonally downward via a bracket welded to the rear end of the main pipe.

[Problem to be solved by the invention]

However, in this structure in which most of the shock absorber is inserted inside the main pipe, the diameter of the main pipe must be increased, which has the disadvantage of restricting the capacity of the fuel tank and the like.

In addition, since most of the shock absorber is inside and covered by the main pipe, not only is the cooling efficiency of the shock absorber due to the running wind relatively low, but it is also difficult to assemble the shock absorber on the upper end side. There is also a problem.

In addition, in a structure where the main pipe has a large diameter and the shock absorber is housed inside, the weight of the main pipe is large and the shock absorber is installed at a high position, which raises the center of gravity of the vehicle and reduces steering stability. It has the disadvantage of being undesirable.

Furthermore, the frame (main pipe/seat pillar tube) between the upper end support part of the shock absorber and the support position of the rear arm is shaped like a curve when viewed from the side, so a large compressive load is applied to the shock absorber. In this case, there is also the problem that the amount of distortion of the frame increases because it acts as a bending load on the frame.

[Means to solve the problem]

The present invention was made to solve the above-mentioned problems, and the upper ends of a pair of seat pillar tubes are connected from the sides to both sides of the rear end of the main pipe, and the upper end of the shock absorber is connected to this connection. It is pivotally supported nearby, and the other end is connected to a rear arm that is pivotally supported below the seat pillar tube.

[Effect]

It can use the same main pipe as a regular motorcycle, and since the shock absorber is exposed to the outside, it is cooled by the wind while driving. Further, the load applied to the shock absorber acts only on the seat pillar tube as a tensile load.

〔Example 〕

Fig. 1 is a side view showing a shock absorber mounting structure for a motorcycle frame according to the present invention, Fig. 2 is a plan view of the frame, Fig. 3 is a view taken in the direction of arrow A in Fig. 1, and Fig. 4 is an IV -IV sectional view. In these figures, the reference numeral 1 indicates a frame for a motorcycle, and this frame I is a steering head pipe 1a.

A main pipe lb, a seat rail 1c and a seat pillar tube ld connected to the rear end of the main pipe 1b via a connecting member described later, a down tube le, if,
It is composed of a backstay 1g, a cross tube 1h, etc. A rear arm 2 is pivotally supported on the frame 1, and the rear arm 2 is formed into a triangular shape when viewed from the side, as shown in FIG. Further, the rear arm 2 is pivotally supported by a rear arm shaft 21 on a bracket 11 welded to the lower part of the seat pillar tube 1d of the frame 1.

3 is a shock absorber interposed between the top of the rear arm 2 and the frame l. As shown in detail in FIG. 4, this buffer 3 prevents dust or mud from entering the seal 3b inside the cylinder 3a, and also has a cylindrical spring guide 3d that guides the coil spring 3c.
, one end (lower end) is connected with a pin 5 to a support part 4 provided at the top of the rear arm, and the other end (upper end) is connected with a pin 7 near the rear end of the main pipe 1b, that is, within the connecting member 6. There is.

This connecting member 6 includes a cylindrical body part 6a into which the rear end of the main pipe 1b is inserted and connected, and a connection having an internal space formed integrally with this cylindrical body part 6a and facing the end of the shock absorber 3. 6b, and is substantially integral with the main pipe 1b. Furthermore, the front end portion of the seat rail ICO and the seat pillar tube 1d are connected to both sides of the connecting member 60, respectively.

Reference numeral 8 denotes an engine body, which is supported by the frame 1 through brackets 9 and 10 welded to the frame 1. 11
is a mudguard, and a cylindrical body 12 through which a shock absorber 3 is inserted is integrally formed in the front part of this mudguard 11.

Since the shock absorber mounting structure of the present invention is configured in this way, pipes similar to those of general motorcycles can be used as the main pipe, and since the shock absorber is completely exposed to the outside, it can be cooled by the wind while driving. be done. Further, the load applied to the shock absorber is received as a tensile load near the rear end of the main pipe to which the seat pillar tube is connected and at the lower part of the seat pillar tube.

In addition, as in the embodiment shown in the drawings, the rear part of the frame is formed into a triangular shape in side view by the seat pillar tube 1d, the seat rail lc, and the backstay 1g that connects these, and a shock absorber is disposed inside the frame. For example, interference with the frame due to swinging of the rear arm does not occur, and in the event of a fall, the shock absorber is protected by these frame members.

〔Effect of the invention〕

As explained above, according to the present invention, the upper ends of the pair of seat pillar tubes are connected from the sides to both sides of the rear end of the main pipe, and the upper end of the shock absorber is pivoted near this connection. Since the other end is connected to the rear arm which is supported under the seat pillar tube, there is no need for a large diameter main pipe into which a shock absorber can be inserted. Therefore, the capacity of the fuel tank disposed around the main pipe can be increased, and since the shock absorber is exposed to the outside, the cooling efficiency by the running wind is improved. Also,
Since the seat pillar tube receives the load applied to the shock absorber as a tensile load, the frame is not distorted and its strength is guaranteed, and together with the reduction in the diameter of the main pipe, the weight of the frame can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a side view showing a shock absorber mounting structure for a motorcycle frame according to the present invention, FIG. 2 is a plan view of the frame, FIG. 3 is a view taken in the direction of arrow A in FIG. 1, and FIG. IV-rV
FIG. 1...Frame, 1b...Main pipe, 1d
...Seat pillar tube, 2...Rear arm, 3...Buffer. Patent applicant Yamaha Motor Co., Ltd. Agent Yamakawa administration (and 1 other person)

Claims (1)

[Claims] The upper ends of a pair of seat pillar tubes are connected from the sides to both sides of the rear end of one main pipe, and the upper end of the shock absorber is pivotally supported near this connection, while the other end is connected to the bottom of the seat pillar tubes. A shock absorber mounting structure for a motorcycle frame characterized by being connected to a shaft-supported rear arm.