JPS61232975A - Frame 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] [Industrial application field] The present invention relates to frames for motorcycles.

[Prior art]

Conventionally, this type of frame has a structure in which the bracket for pivotally supporting the rear arm is formed into a plate shape with a predetermined wall thickness by casting, for example, and the Radvibe is connected to the steering wheel via left and right main pipes. Are known.

In such a frame, for example,
As seen in Japanese Patent No. 16655, the above-mentioned bracket is used as a member for attaching a side stand and a change pedal.

[Problem that the invention seeks to solve]

However, with this frame configuration, the side stand and pedals pass outside the bracket, which increases the amount of outward protrusion in the vehicle width direction. This not only obstructs getting on and off the vehicle, but also causes problems such as a shallow bank angle due to the fact that the bracket is located at the lower part of the frame.

[Means for solving problems]

Therefore, in the present invention, on the outer surface of the lower end of a plate-shaped bracket made of a cast or forged product, an inclined surface is formed which is inclined inward in the vehicle width direction while keeping the wall thickness substantially constant as it goes downward. The invention is characterized in that various functional parts, such as a shift rod connected to a change pedal, are arranged on the outside of this inclined surface.

[Effect]

According to this configuration, a space that extends inward in the vehicle width direction is formed on the outer side of the lower end of the bracket, so this space can be used as a storage space for various functional parts. Therefore, various functional parts can be placed closer to the inside in the vehicle width direction, so they do not interfere with getting on and off the vehicle, and
It is also possible to secure a sufficient bank angle.

Further, since the wall thickness of the bracket is basically kept substantially constant, sudden changes in the cross-sectional shape can be suppressed and sufficient rigidity can be ensured.

[Embodiments of the invention]

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

In the figure, 1 is an aluminum alloy frame, and a front fork 3 is pivotally supported by a steering head pipe 2 placed vertically at the front end of the frame. A pair of left and right main vibes 4, 4 are welded to the steering head vibe 2 and extend rearward and diagonally downward in a straight line in a side view. The main vibes 4, 4 of this embodiment are thin-walled, and their cross-sectional shape is formed into a flat rectangular cylinder shape that is vertically elongated. In order to increase the connection strength and rigidity, the vertical dimension is formed to be approximately equal to the axial length of the Radvibe 2 described above. Furthermore, the vertical dimensions of the main vibes 4, 4 are gradually reduced as they move rearward, so that the side shape of the main vibes 4.4 becomes tapered as they move rearward. Further, the main vibes 4.4 are expanded outward in the vehicle width direction immediately after the steering head pipe 2, and then extend parallel to each other to the rear, and brackets 5a and 5b are welded to the rear ends of the main vibes 4.4. ing. A down tube 7 is installed between the lower front ends of the brackets 5a, 5b and the cross vibe 6 that connects the front ends of the main vibes 4, 4. An engine 8 is mounted between the two.

Incidentally, the brackets 5a and 5b are made of cast aluminum alloy, for example, and the outer plate 29 facing the side of the vehicle body is formed into a flat plate shape with a predetermined wall thickness. A rib wall 30 that extends inwardly is continuous and integrally cast in the circumferential direction on the outer peripheral edge of the rib wall 30 . Then, the outer plate 29 of the brackets 5a and 5b
are connected at their upper and lower ends via cross vibes 9a and 9b, and between these brackets 5a and Sb, the front end of a rear arm 1o extending rearward is pivoted via a pivot shaft 11 so as to be swingable in the vertical direction. has been done. rear arm 1
0 has a rear wheel 12 pivotally supported at the rear end, and a sprocket 13 on the rear wheel 12 side and a sprocket 14 on the engine 8 side.
A chain 15 is wound between the bracket 5a and the chain 15, and the chain 15 passes directly inside the left bracket 5a.

Immediately after the pivot portion of the rear arm 10, one hydraulic shock absorber 28 is placed vertically along the vertical direction to receive the swing stroke thereof.

As shown in FIG. 1, the outer plates 29 of the brackets 5a and 5b are inclined inward in the vehicle width direction while keeping the wall thickness constant as they move downward under the pivot shaft 11. In the portion, the protruding height H of the rib wall 30 is continuously reduced in accordance with the above-mentioned inclination. Therefore, due to the presence of the inclined surface 16, a space portion 17 is formed at the outer side of the lower end of the brackets 5a, 5b, which extends inward in the vehicle width direction.

On the rear surfaces of the upper ends of the left and right brackets 5a and 5b, there are footrest brackets 18 that extend rearward, respectively.
(only one of which is shown) is bolted to the rear end of this footrest bracket 18.
．． 19 is supported. Further, on the outer surface of the left footrest bracket 18, a boss portion 20a at the base end of a change pedal 20 is pivotally supported coaxially with the footrest 19, and the base end of the change pedal 20 is placed on the front engine 8 side. The shift arm 21 is connected to the shift arm 21 provided in the shift arm 21 via a shift arm 22 extending in the front-rear direction. In addition, a side stand 24 is pivotally supported at the front end of the lower end of the left side bracket 5a via a stand bracket 23 so that it can be raised and lowered. It extends. The shift rod 22 extends along the front-back direction in the space 17 on the outside of the inclined surface 16, and
The side stand 24 also extends diagonally below the space portion 17 in the front-rear direction, so in this embodiment, the shift rod 22 and the side stand 24 are connected to the bracket 5a.
It constitutes a functional component located on the outside of the

Note that a brake pedal (not shown) is pivotally supported at the rear end of the right footrest bracket 18.

Further, reference numeral 27 in the figure indicates a spring that biases the side stand 24 in the storage direction.

According to such a configuration, a space portion 17 that extends inward in the vehicle width direction can be formed on the outer side of the lower end of the brackets 5a, 5b, and this space portion 17 can be effectively used as a storage space for the shift rod 22. Moreover, the side stand 24 can be placed closer to the inside in the vehicle width direction by the amount that the outer plate 29 of the bracket 5a is inclined. The overhang can be kept to a minimum so that it does not become a hindrance when getting on and off, and a sufficient bank angle can be secured.

In addition, the outer plates 29 of the brackets 5a and 5b are tilted toward the inside of the vehicle body while keeping their wall thickness basically constant, and the height of the rib wall 30 on the outer peripheral edge thereof is continuously adjusted according to the inclination. Since the brackets 5a and 5b have been reduced
The wall thickness is kept approximately uniform over the entire area, and rapid changes in the cross-sectional shape are suppressed. Furthermore, due to the presence of the ribs 9130, the brackets 5a and Sb themselves are formed into a shallow container shape, so that the rigidity and strength of the brackets 5a and 5b are further increased compared to the case where a single plate is simply bent. It can sufficiently withstand shocks, blows, twists, etc. caused by rocking.

Note that the frame according to the present invention is not limited to being made of aluminum alloy.
It may be made of general steel, and the bracket itself is not limited to a cast molded product, but may be a forged molded product.

Further, the functional parts are not limited to the shift rod and the side stand, but may also be wires, for example.

(Effects of the Invention) - According to the present invention described in detail above, the space on the outer side of the lower end of the bracket can be effectively used as a storage space for functional parts such as a shift rod. The outward protrusion is kept to a minimum, so there is no obstruction when getting on and off, and a sufficient bank angle can be secured.In addition, the wall thickness of the bracket is basically kept almost constant, so it has sufficient rigidity. It can be ensured that there are no problems in terms of strength.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, in which Fig. 1 is a partially sectional front view of the bracket, Fig. 2 is a view taken in the direction of the arrow in Fig. 1, and Fig. 3 is a view of the bracket. A partially sectional plan view of the surrounding area, Figure 4 is a view in the direction of the arrow in Figure 5,
FIG. 5 is a side view of the motorcycle. 2... Steering head pipe, 4... Main pipe, 5a, 5b... Bracket, 10... Rear arm, 16... Inclined surface, 22... Functional parts (shift rod).

Claims (1)

[Claims] A plate-shaped bracket made of a cast or forged product for pivotally supporting the front end of the rear arm is provided at the rear end of a pair of left and right main pipes extending backward and downward from the steering head pipe, and approximately front and rear brackets are provided on the outside of these brackets to support the front end of the rear arm. In a motorcycle frame in which various functional parts extending in a direction are arranged, the outer surface of the lower end of the bracket is inclined inward in the vehicle width direction while keeping the wall thickness substantially constant as it goes downward; A frame for a motorcycle, characterized in that the various functional parts described above are arranged on the outer side of the frame.