JPS6334076B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION A seat of a motorcycle is mounted on seat rails forming the rear part of a frame, and the seat rails are provided on the left and right sides and are connected by a cross member. By the way, the rear wheel is installed below the seat rail so that it can swing up and down, and it is necessary to install the cross member so that it does not interfere with it at the upper limit of its swing position. According to this, the cross member is in a high position, and the seat rail is also in a high position. position, resulting in a higher seat and a higher center of gravity.

The present invention has been made in view of the above, and its object is to extend the left and right seat rails to the sides near the upper limit position of the rear wheel, and to extend the left and right seat rails to the side near the upper limit position outline of the rear wheel. The seat rail is connected by a cross member facing the rear wheel, and the cross member is made of pipe material with a circular cross section, and the position of the seat rail is kept as low as possible to avoid interference between the cross member and the rear wheel. To provide a frame structure for a motorcycle that allows the seat to be set low and the center of gravity to be kept low.

Next, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

Fig. 1 is a schematic side view of the motorcycle, Fig. 2 is a side view of the frame, Fig. 3 is a plan view of the same, and Fig. 4 is a schematic side view of the motorcycle.
The figure shows an enlarged plan view of the main parts of the frame.

The motorcycle 1 supports a front fork 4 which supports a front wheel 5 through a head tube 3 at the front end of a frame 2 in a steerable manner, and the frame 2 is constructed as follows.

The details of the frame 2 are as shown in Fig. 2, with left and right main pipe parts 2a, 2a extending rearward and downward from the upper part of the head tube 3, and a middle part of the main pipe part 2a extending rearward from the lower part of the head tube 3. The joined extension member 2b, the left and right down tube portions 2c hanging downward from the intermediate portion of the member 2b, the down tube blower portion 2d extending rearward from the lower end thereof, and the rear end of the lower portion 2d. In the embodiment, the rearwardly curved portion 2e
The main pipe part 2a is connected to the center pipe part 2f, the curved part 2e thereof, and the lower part. 2
d. The down tube part 2c is made by bending a single square pipe into a substantially triangular shape with curved corners, which are arranged on the left and right, and connected at appropriate points with cross pipes of the same cross section. Using. The curved portion 2e
A reinforcing gusset 6 is welded to the front inner edge of the curved portion 2e, a rear fork bracket 7 is provided at the middle of the front inner edge of the curved portion 2e, and engine hanger brackets 8 are provided above and below this, and reinforced with the gusset 6. The middle part 9 is a bracket provided on the down tube part 2c.

Left and right Atsuppa pipes 2g forming seat rails extend rearward from the middle part of the main pipe part 2a so as to be slightly upwardly tilted, and as shown in FIG. The upper part of the rear outer edge is connected by a subtube 2h forming a diagonal girder, and the top pipe 2g and the subtube 2h are constructed of square pipes.

The fuel tank 10 is placed on the main pipe part 2a of the frame 2, and the Atsupa pipe 2g is located behind it.
Seats 11 are mounted on the top, and an engine 12 is mounted below the tank 10. In the embodiment, the engine 12 is a water-cooled engine with a horizontal V-shaped crankshaft, and the rear cylinder 12b is approximately upright and has left and right sides. The engine is equipped with two cylinders, and the front cylinder 12a is configured with one cylinder, protruding forward, so that a three-cylinder engine is used. Upper and lower divided radiuators 13 and 14 are provided at the front upper and lower parts of the down tube portion 2c, and the front part of the frame, the sides of the radiuators, and the engine are covered with a fairing 15.

The front end of a rear fork 16 that supports the rear wheel 17 is pivotally attached to the bracket 7 at the middle of the front inner edge of the curved portion 2e, and the exhaust pipes 18, 1 of the engine 12
8 extends rearward and upward from the cylinder, and is connected to the exhaust pipe 1.
8 and 18 are led out from the inside of the center pipe 2f to the upper rear and outer side of the triangular space of the upper pipe 2g and the subtube 2h, and are extended rearward along the rear lower part of the upper pipe 2g, and are further extended to the left and right sides as shown in the third figure. The end portions of the exhaust pipes 18, 18 are bent in opposite directions and are connected to mufflers 19, 19 extending rearward, respectively, and the middle to rear portions of the exhaust pipes, the muffler, etc. are covered with a rear cowl 20.

In the above, the rear end portions 2g' and 2g' of the Atsupa pipes 2g and 2g face above the center of the rear wheel 17 to form an expanded portion, and the cross pipe 21 is horizontally connected between these portions. are both ends 21a, 2
Weld 1a to the rear end of the Atsuppa pipe 2g', 2g',
The intermediate portion 21b is curved upward and, in the embodiment, backward, so that it does not interfere with the upper limit of movement when the rear wheel 17 swings up and down, and the cross pipe 21 is short.
In addition, it is formed from a round pipe material in order to perform bending into a three-dimensional shape.

On the other hand, a secondary subtube 22 is provided between the middle part of the subtube 2h and the rear part of the upper pipe 2g in a diagonal girder shape so as to connect this space, and the secondary subtube 22 connects the outside of this part to the middle part 18a of the exhaust pipe 18. pass close together, the middle part bulges out, and is moved as close to the inside as possible in order to suppress the vehicle width. Therefore, the secondary subtube 22 has a three-dimensional shape in which the intermediate portion is curved inward of the vehicle body, and the secondary subtube is short and formed of a round pipe to be bent into a three-dimensional shape.

Next, to explain the function and effect in detail, since the cross pipe that forms the cross member provided to connect the atsupah pipes that form the seat rail is curved upward, the cross pipe and the rear wheel at the upper limit position of the rear wheel are Interference can be avoided by placing the cross pipe and the rear wheel as close as possible, and by curving the cross member, the Atsupa pipe can be extended to the side of the upper limit position of the rear wheel at a low position. The installed seat is as low as possible to keep the center of gravity low.Also, the area near the seat attachment part of the seat rail is made narrower, making it easier for the driver to straddle and improve footing. Since the rear part of the seat mounting part is expanded to at least partially surround the rear wheel movable range in plan view, the seat can be placed at a position lower than the upper limit of the rear wheel movable range, thus providing extremely high footing and sufficient stability. You can get the stroke of the rear wheel.

Furthermore, the cross member between the seat rails was curved upward to bring it closer to the upper limit of the rear wheel's range of motion.
For example, even when a seat cowl is mounted on a seat rail, the seat cowl can be supported by the cross member, and a predetermined distance can be maintained between the seat cowl and the tire.

[Brief explanation of the drawing]

FIG. 1 is a schematic side view of the motorcycle, FIG. 2 is a side view of the frame, FIG. 3 is a plan view thereof, and FIG. 4 is an enlarged plan view showing details of main parts of the frame. In addition, 1 in the drawing is a motorcycle, 2 is a frame, 2
2g and 2g are seat rails, 18 is an exhaust pipe, 21 is a cross member, and 22 is a member adjacent to the exhaust pipe.

Claims (1)

[Scope of Claims] 1. Left and right seat rails forming the rear part of the vehicle body, on which seats are attached and supported on the upper surface, the rear ends of the left and right seat rails extending near the upper limit position of the movable range of the rear wheels, and An expanding portion that forms a narrow space between the left and right seat rails near the mounting portion, and expands the space between the seat rails rearward from the seat mounting portion to at least partially surround the movable range of the rear wheel in a plan view. A frame for a motorcycle, further comprising: a cross member that curves upward at the upper limit position of the movable range of the rear wheel and close to the outer contour line in side view. structure.