JPS62113670A - Frame structure of 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 frame structure for a motorcycle, and particularly to a frame structure suitable for an off-road motorcycle.

[Prior art]

The types of frames for motorcycles are broadly classified into cradle frames and diamond frames. Whereas the former cradle frame has a structure in which the lower part of the front frame and the lower part of the rear frame are integrated and continuous,
The latter diamond frame has a structure in which the front frame and the rear frame are independent, and the engine itself becomes part of the frame and is connected between the lower parts of both frames.

With the Diamond Frame, both the front and rear frames are independent and the lower parts are separated, so when installing or removing the engine, you can do so while it is on the ground, etc., without lifting it up. Therefore, a diamond frame has the advantage that it is much easier to attach and detach the engine than a cradle frame. However, from the point of view of frame strength, the diamond frame is inevitably disadvantageous compared to the cradle frame, in which the front and rear frames are integrated.

[Purpose of the invention]

An object of the present invention is to provide a frame structure for a motorcycle that maintains the advantage of a diamond frame in which the engine can be easily attached and detached, improves the strength of the frame to that of a cradle frame, and protects the engine from flying stones, etc. It is about providing.

[Structure of the invention]

To achieve the above object, the present invention provides a motorcycle with a diamond frame structure in which a front frame and a rear frame are each independently constructed, and an engine is connected as a part of the frame between the lower portions of both the front and rear frames. The engine is characterized in that a protection plate is provided to cover the lower part of the engine, and the front and rear ends of the protection plate are connected to the lower part of the front frame and the lower part of the rear frame, respectively.

〔Example〕

The present invention will be explained below with reference to embodiments shown in the drawings.

FIG. 1 shows an off-road motorcycle, where 1 is a body frame and 2 is an engine mounted on this body frame 1. FIG. The body frame 1 has a main pipe 3 arranged at the top, and a head pipe 4 fixed to the front end of the body frame 1. A front frame 5, also called a down tube, extends downward from the head pipe 4. A rear frame 6, also called a seat pillar, extends downward from the rear. Both the front and rear frames 5, 6 are made of mutually independent members.

A stay 7 for mounting the engine 2 is fixed to the lower part of the front frame 5, and a bracket 8 for mounting the engine 2 is fixed to the lower part of the rear frame 6. The stay 7 fixes the lower front end of the engine 2 with two bolts 9 and 10, and the bracket 8 fixes the lower rear end of the engine 2 with bolts 11. At the same time, a rear arm 12 is pivotally supported on the bolt 11, and a rear wheel 13 is supported at its rear end. As mentioned above, the lower surface of the engine 2 supported by both the front and rear frames 5.6 is covered by the protection plate 14, and the front end of the protection plate 14 is connected to the stay 7.
The rear end is fixed to the lower end of the rear frame 6, and the rear end thereof is fixed to the lower end of the rear frame 6.

The protection plate 14 is connected to the engine 2 as shown in the perspective view of FIG.
It is molded from a light metal such as aluminum in a curved shape so as to cover the entire lower surface and part of the front and both sides. Although not shown in the drawings, holes may be drilled in several places to reduce weight if necessary. Good too. A mounting boss 15.15 is welded to the rear end of this protection plate 14, and a mounting plate 16 is welded to the front end.
．． 16 are welded. In this case, the mounting boss 15 is installed so that its lower part protrudes below the lower surface of the protection plate 14, so that the height of the protection plate 14 from the ground (minimum ground height) is as high as possible. There is. 17 is a boss fixed between the lower ends of the mounting plates 16 and 16, and 18 is a reinforcing plate around the bolt adjustment hole.

The protection plate 14 is attached to both the front and rear frames 5.6 with respect to the attachment boss 15.15 at the rear end.
As shown in Figure 3, a bracket 20. is welded to a cross member 19 fixed between the lower ends of the left and right rear frames 6.6.
20 with bolts 21.21 and 22.22. Regarding the front end mounting plate 16.16,
As shown in FIG. 4, it is fixed by projection nuts 23, 23 and bolts 24, 24 welded to the stay 7.

In the vehicle body frame 1 described above, when installing the engine 2, protect plates 14 are attached to both the front and rear frames 5.6.
This can be done before installing. Since the protection plate 14 is not attached, the lower ends of both the front and rear frames 5 and 6 are separated, so the engine 2 is placed on the ground ring without being lifted up like a normal diamond frame. It can be installed as is, making work much easier.

Further, when the engine 2 is to be removed, the protection plate 14 is first removed and then placed on the ground ring, and the vehicle body frame 1 can be removed in this state. Therefore, the work can be made as easy as with a conventional diamond frame.

In addition, in the final assembled state, the lower ends of both the front and rear frames 5.6 are connected by the protection plate 14, so this protection plate 14 becomes a strength member, making the frame strength equivalent to that of a conventional cradle frame. Or more.

〔Effect of the invention〕

As described above, the present invention provides a motorcycle with a diamond frame structure in which a front frame and a rear frame are configured independently, and an engine is connected as a part of the frame between the lower portions of both the front and rear frames. A protection plate is provided to cover the lower part of the engine, and the front and rear ends of this protection plate are connected to the lower part of the front frame and the lower part of the rear frame, respectively, so when the engine is attached to or removed from the body frame, the protection plate is removed. By doing this,
This can be easily done with the engine placed on the ground ring, similar to the conventional diamond frame. In addition, after assembly, the protection plate connects the lower ends of both the front and rear frames, so the frame can exhibit the same strength as a cradle frame, and the protection plate protects the engine from flying stones, etc. I can do it.

[Brief explanation of drawings]

Fig. 1 is a side view of an off-road motorcycle equipped with a body frame according to an embodiment of the present invention, and Fig. 2 is a side view of an off-road motorcycle equipped with a body frame according to an embodiment of the invention.
- An arrow view showing the A cross section on the right side and the B-B arrow cross section on the left side, Figure 3 is a sectional view taken along the line D-D in Figure 2, and Figure 4 is C in Figure 1. -C arrow sectional view and FIG. 5 are perspective views of the protection plate used in the present invention. 1--Vehicle frame, 2--Engine, 3-
・Main pipe, 4-Head pipe, 5...Front frame, 6-Rear frame, 7-Stay,
8--Bracket, 14--Protection plate, 15
...Mounting boss, 16--Mounting plate, 21.22.2
4.-volt. Figure 2 Figure 5 Old

Claims (1)

[Claims] In a motorcycle having a diamond frame structure in which a front frame and a rear frame are each independently constructed, and an engine is connected as a part of the frame between the lower parts of both the front and rear frames, a protection plate is provided to cover the lower part of the engine. A frame structure for a motorcycle, characterized in that the front and rear ends of the protection plate are respectively connected to the lower part of the front frame and the lower part of the rear frame.