JPH0478682A - Body structure for motorcycle - Google Patents

Abstract

PURPOSE:To improve the blow-by of travel air by connecting the respective rear end parts of a lateral pair of main frames to each other by a cross member, then fitting a supporting member of approximately semi-circular cross section to the approximate center part of the cross member in such a way as to be extended upward, and positioning a rear cushion behind this supporting member. CONSTITUTION:The body frame 2 of an off-road motorcycle is extended backward to the rear from a head pipe 3. The body frame 2 is provided with a lateral pair of main frames 6, and an upper cross member 16 is connected to both connecting brackets 15 connected to the respective rear end parts of the main frames 6. A supporting member 17 of approximately semi-circular cross section is fitted, in the state of being extended upward, to the approximate center part of the upper cross member 16. The rear end of a rear arm is pivotally supported on the end part of a rear bracket with its upper end part fixed to the connecting member 15, and the upper end part 33b of a rear cushion 33 for buffer-supporting this rear arm is supported on the upper part of the supporting member 17 in such a way as to be rotatable around a supporting pin 43 as a fulcrum, thereby disposing the rear cushion 33 behind the supporting member 17.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a motorcycle body structure, and more particularly to a motorcycle body structure that supports a rear cushion.

[Prior Art] In some motorcycles, for example, a rear arm that supports a rear wheel is pivotally supported by the vehicle body, and this rear arm is swingably supported by the vehicle body by a rear cushion.

For example, as disclosed in Japanese Patent Application No. 59-55137,
Attach seat rails to the rear ends of the pair of left and right main frames that extend backward and downward from the head vibe.
The upper end of the rear cushion is attached to a cross member connected between the seat rails, while the lower end of the rear cushion is attached to a link mechanism that supports the rear arm on the vehicle body.

[Problems to be Solved by the Invention] Incidentally, in motorcycles, running wind is actively introduced into the engine to cool the engine.
For example, in the case where the left and right seat rails are bent close to each other at the cross member attachment position as described above, and the rear cushion is supported on the cross member attached to this bent part, these support members prevent the air from blowing through the vehicle. is being obstructed.

In addition, since the stress of the rear cushion is applied in a direction perpendicular to the axial direction of the cross member, it is necessary to make the cross member large to prevent bending, which increases the weight and increases the weld strength of the cross member. There are problems such as the need for special improvement.

This invention has been made in view of these circumstances, and provides a motorcycle body structure that allows running air to flow easily behind the engine, improves the mounting strength of the rear cushion, and makes it possible to reduce the size and weight of the motorcycle. is intended to provide.

[Means for Solving the Problems] In order to solve the above problems, the motorcycle body structure of the present invention connects the rear ends of a pair of left and right main frames extending rearward and downward from a head vibrator with a cross member, A support member having a substantially semicircular cross section facing the direction of vehicle travel is attached to the approximately central portion of this cross member so as to extend upward;
The present invention is characterized in that a rear cushion is positioned behind the support member, and the upper end of the rear cushion is attached to the support member.

[Function] In this invention, a support member is attached to a substantially central portion of a cross member that connects the rear end portions of a pair of left and right main frames,
A rear cushion is positioned behind this support member, and the upper end of this rear cushion is attached to the support member.
Spaces are formed above the support member and on both left and right sides. For this reason, the traveling wind that cools the carpenter is guided by the space above the support member and the support member, and flows smoothly rearward from the spaces on both sides thereof, improving the blow-through to the rear.

Further, a support member is attached to the approximately central portion of the cross member so as to extend upward, and the upper end portion of the rear cushion is attached to this support member. By aligning the axial direction of the support member with the direction of stress in the cushion, the strength and rigidity of the support member of the rear cushion are ensured.

[Embodiments] Next, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a side view of a motorcycle to which an embodiment of the present invention is applied, FIG. 2 is a side view of a vehicle body frame, FIG. 3 is a central sectional view of the vehicle body frame, and FIG. 4 is a TV- TV sectional view, Fig. 5 is a V-V sectional view in Fig. 2, Fig. 6 is a Vl-Vl sectional view in Fig. 3, Fig. 7 is a -■ sectional view in Fig. 3,
Figure 8 is a partially cutaway side view of the main frame, Figure 9
FIG. 8 is a sectional view taken along the line ■-■.

Reference numeral 1 in the figure is an off-road motorcycle, and a head vibe 3 that constitutes a body frame 2 has a front fork 4.
is supported, and a front wheel 5 is provided at the lower end of the front fork 4. A pair of left and right main frames 6 are connected to the head vibrator 3 and extend rearward and downward from the head vibrator 3.

A reinforcing plate 7 is welded to the lower side of the connection between the head vibe 3 and the main frame 6, a side plate 8 is welded to the side thereof, and a reinforcing plate is welded between the reinforcing plate 7 and the main frame 6. 9 is welded to strengthen the connection between the head vibe 3 and the main frame 6.

As shown in FIGS. 8 and 9, the main frame 6 has a rectangular frame 60 with a vertically elongated cross section formed of extruded aluminum, and the frame 60 further has a window 60a.
, 60b are provided. A honeycomb panel 61 is inserted into the frame frame 60, and this honeycomb panel 61 is made of aluminum and is made of a honeycomb material 62 formed with a plurality of hexagonal columnar molded holes 62a arranged in a honeycomb shape. Plate 63 fixed to close both sides
It consists of The honeycomb panel 61 is fixed by welding at the edges of the window portions 60a and 60b of the frame frame 60, and the main frame 6 is made of the honeycomb panel 61 configured as described above, which is lightweight while maintaining high rigidity. .

A frame frame 60 is located in front of the center of the main frame 6.
A mounting hole 64 is formed in the mounting hole 64, and the mounting member 10 is fixed to the mounting hole 64. The upper end 11a of the down tube 11 is tightened and fixed to the mounting member 10 with bolts 12, and the lower end 11b of the down tube 11 is fixed to the mounting member 10. An engine mounting bracket 13 is welded to. Further, a fuel tank mounting bracket 14 is welded to the rear side of the central portion of the main frame 6.

A connecting bracket 15 is connected to the rear end of the main frame 6 by welding, and an upper cross member 16 is connected between the connecting brackets 15 by welding. A support member 17 having a substantially semicircular cross section facing the vehicle traveling direction is attached to the approximately central portion of the upper cross member 16 so as to extend upward, and a reinforcing member 18 is welded to the inside of this support member 17. ing. Further, mounting plates 19 are welded to both rear ends of the support member 17, and side plates 20 are welded to the support member 17 and the mounting plates 19. This mounting plate 19 and side plate 2
A backstay attachment member 21 is welded to the rear end of the
The front end 22a of the backstay 22 is fastened and fixed to the backstay attachment member 21 with bolts 23. The rear end 248 of the seat rail 24 is connected to the rear end 22b of the backstay 22, and the front end 24b of the seat rail 24 is connected to a seat rail mounting member fixed to the approximate center of the main frame 6. 25 with bolts 26. The seat rail mounting member 25 is formed with a guide portion 25a that supports the front end 24b of the seat rail 24, and the backstay mounting member 21 is also formed with a guide portion 21a that supports the front end 22a of the backstay 22. Both guide portions 25a and 21a are formed parallel to each other.

The upper ends of a pair of left and right rear arm brackets 27 are tightened and fixed to a connecting member 15 fixed to the rear end of the main frame 6 with bolts 28, and a connecting member 29 is connected between the lower ends of the rear arm brackets 27 with bolts 30. A lower cross member 31 is connected to the inside of this connecting member 29 by welding.

Inside the pair of left and right rear arm brackets 27, a pair of left and right reinforcing plates 32 are welded between the upper cross member 16 and the lower cross member 31, and the pair of left and right reinforcing plates 32 are arranged at an interval that allows the rear cushion 33 to be positioned. It is located in

Further, a front end portion 34a of a rear arm 34 is rotatably supported on each rear arm bracket 27 via a support shaft 35, and a rear wheel 36 is supported at the rear end portion of the rear arm 34. An end portion of a rear arm side link 37 is pivotally supported on a support shaft 38 approximately at the center of the rear arm 34, and the other end portion of this rear arm side link 37 is rotatably supported at one end portion of a vehicle body side link 39 via a support shaft 40. The other ends of the vehicle body side links 39 are rotatably supported by support shafts 41 inserted through lower cross members 31 fixed to the left and right rear arm brackets 27.

A lower end 33a of the carrier cushion 33 is rotatably supported at the end of the vehicle body side link 39 with a support bin 42 as a fulcrum.
The upper end 33b of this rear cushion 33 is connected to the support member 17.
It is rotatably supported on the upper part of the support bin 43 as a fulcrum. The rear cushion 33 includes the supporting member 17 and the reinforcing member 1.
8, and this supporting member 17 and reinforcing member 18
Furthermore, it is surrounded by a mounting plate 19 and a side plate 20, so that the support member 17 is provided on both sides of the cushion 33.
A space 44 is formed between the side plate 20 and the rear end portions of the pair of left and right main frames 6, the connecting member 15, the rear arm bracket 27, etc., and above the support member 17.

The rear part of the engine 45 is supported by the rear arm bracket 27, the lower rear part of the engine 45 is supported by the rear arm bracket 27, and the lower front part is supported by the lower part of the down tube 11.

This engine 45 is a single cylinder two-stroke engine, and a carburetor 46 is provided at the rear of the engine 45, and the carburetor 46 is connected to an air cleaner 47. This air cleaner 47 is formed in a shape that follows the space 44 on the left side of the support member 17 and the side plate 20, and has a smooth shape that reduces air intake resistance and can increase the cross-sectional area, thereby increasing air intake efficiency. is improving.

Furthermore, an exhaust pipe 48 is connected to the rear of the cylinders of the engine 45, and this exhaust pipe 48 extends rearward through the support member 17 and the space 44 on the right side of the side brake 1-20, and further extends at a position above these. A seat 5o is placed on the main frame 6 and the seat rail 24, and the lower side of the seat rail 24 is covered with a sight cover 51.

The lower part of the engine 45 is covered by an engine guard 52, and this engine guard 52 covers the down tube 11.
and a connecting member 29 fixed to the rear arm bracket 27. A fuel tank 49 is arranged above the engine guard 52 so as to surround the cylinders of the engine 45 from the front side to both sides, and the fuel tank 49 is supported by the fuel tank mounting bracket 14 of the main frame 6. Further, a radiator 53 is attached to the down tube 11 above the fuel tank 49, and a front cover 54 is provided on both sides of the radiator 53. The front cover 54 directs the running wind to the radiator 53 and the engine 45. The system has been introduced and these are now being rejected.

This running wind is absorbed by the rear cushion 33 or its front side covered by a semicircular support member 17, as shown in FIG.
It flows rearward as shown by the arrow along the spaces 44 formed above and on both left and right sides of the support member 17, and escapes rearward.

Further, a support member 17 is provided approximately at the center of the upper cross member 16.
is attached so as to extend upward, and the upper end portion 33b of the tension member 33 is attached to this support member 17,
The support member 17 that supports the rear cushion 33 has a substantially semicircular cross section, and the axial direction of the support member 17 coincides with the stress direction of the rear cushion 33, so that the strength and rigidity of the support member 17 are increased. Secured.

In this embodiment, a connecting member 1 is attached to the rear end of the main frame 6.
5 and connect the upper cross member 16 between the connecting members.
Although the support member 17 is attached by connecting the main frame 6, a cross member may be attached directly between the rear ends of the main frame 6.
Alternatively, a rear arm bracket may be attached to the rear end of the main frame, a cross member may be attached between the rear arm brackets, and a support member may be attached to this cross member.

[Effects of the Invention] As described above, in the present invention, a support member is attached to the approximate center of the cross member that connects the rear ends m of the pair of left and right main frames, and the rear cushion is positioned behind the support member. Since the upper end of this rear cushion is attached to the support member, a space is formed above the support member and on both sides of the support member, and this space allows the wind to smoothly flow backwards.
The flow of wind when traveling is not obstructed, and the airflow to the rear is improved.

Further, a support member is attached to a substantially central portion of the cross member so as to extend upward, and the upper end portion of the rear cushion is attached to this support member, and the support member has a substantially semicircular cross section, and the rear cushion By aligning the axial direction of the support member with the direction of the stress, the strength and rigidity of the support member is ensured.

[Brief explanation of drawings]

FIG. 1 is a side view of a motorcycle using an embodiment of the present invention, FIG. 2 is a side view of the vehicle body frame, FIG. 3 is a central sectional view of the vehicle body frame, and FIG. 4 is a N-- N sectional view,
Figure 5 is a sectional view taken along the line V-V in Figure 2, and Figure 6 is a cross-sectional view taken from Figure 3.
■Cross-sectional view, Figure 7 is a cross-sectional view taken along
The figure is a sectional view taken along ■-■. In the figure, numeral 1 is a motorcycle, 2 is a body frame,
6 is a main frame, 15 is a connecting bracket, 16 is an upper cross member, 17 is a supporting member, 18 is a reinforcing member, 1
9 is a mounting plate, 20 is a side plate, 27 is a rear arm bracket, and 33 is a tensioner. Diagram

Claims (1)

[Claims] The rear ends of the pair of left and right main frames extending rearward and downward from the head pipe are connected by a cross member, and a support member having a substantially semicircular cross section facing the vehicle traveling direction is provided at approximately the center of the cross member and extends upward. A vehicle body structure for a motorcycle, characterized in that a rear cushion is positioned behind the support member, and an upper end of the rear cushion is attached to the support member.