JP3362155B2 - Motorcycle frame structure - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motorcycle frame structure. [0002] The rear wheel of a motorcycle is rotatably supported at the rear end of a rear arm, and the front end of the rear arm is rotatably supported by a rear arm bracket forming a part of a body frame. . [0003] [SUMMARY OF THE INVENTION Incidentally, conventionally, since the rear arm bracket was casting such as, for example, an aluminum alloy, is that materials and manufacturing costs are high, a factor increasing the cost of the entire body frame I was The present invention has been made in view of the above problems, and an object of the present invention is to provide a motorcycle frame structure which is inexpensive and can secure necessary and sufficient strength and rigidity. [0005] In order to achieve the above object, the present invention provides a rear arm bracket having a pair of right and left rear arm brackets.
Insert and fix the arm mounting boss, and secure the rear arm mounting
Rear shaft by a pivot shaft
The front end of the arm can be pivoted up and down on the rear arm bracket.
Frame structure of motorcycles
The rear arm bracket is constituted by a channel member having a U-shaped cross section obtained by press-forming a plate material, and the periphery of the open end is welded to the corner of the pipe frame.
Pressing of the periphery of each rear arm bracket
A notch is formed in the shape, and the rear arm is attached to the notch.
The boss is fitted and welded . According to the present invention, the channel member constituting the rear arm bracket can be easily obtained by press-forming an inexpensive steel plate, for example, so that its material and manufacturing cost are reduced as compared with the conventional case. . Further, since the channel member is formed in a U-shaped cross section, necessary and sufficient strength and rigidity are ensured due to its geometric shape, and the channel member is configured to be lightweight.
The channel member is welded in such a manner that the peripheral edge of the opening end is closely adhered to the pipe frame along the outer periphery of the pipe frame, so that the necessary and sufficient mounting strength is secured to the rear arm bracket. In addition, each rear arm bracket
The rear arm into the notch formed in the pressed part of the
Since the attachment boss is fitted and welded,
Is part of the rear arm mounting boss a rear arm bracket?
Exposed, and the edge (ridge line) of the exposed part is also welded
Therefore, the welding length becomes longer, and the rear arm mounting boss
The notch into which is fitted is the high rigidity of the rear arm bracket.
Formed in the pressed part,
The mounting strength of the boss is increased. An embodiment of the present invention will be described below with reference to the accompanying drawings. First, a schematic structure of a motorcycle will be described with reference to FIG. FIG. 13 is a side view of the motorcycle. In FIG. 13, reference numeral 1 denotes a head pipe constituting a part of a body frame, and a steering shaft (not shown) is rotatably inserted into the head pipe 1. The handle 2 is attached to the upper end. An upper end of a front fork 3 is attached to the steering shaft, and a front wheel 4 is rotatably supported at a lower end of the front fork 3. On the other hand, a pair of left and right tank rails 5 and a down tube 6 constituting a body frame extend upward and downward from the head pipe 1, and a space formed by the two extends into a four-cycle 4. Cylinder engine 7
Is stored. A fuel tank 8 is arranged above the engine 7, and a tandem seat 9 is arranged behind the fuel tank 8. Note that four exhaust pipes 10 extend from the engine 7, and these exhaust pipes 10 are assembled and connected to one muffler 11 disposed on one side of the vehicle body. A pair of left and right rear arm brackets 12 is connected to a corner portion where the tank rail 5 and the down tube 6 are joined, and the front end of a rear arm 13 is connected to the pivot shaft 1.
At 4, it is supported so as to be rotatable up and down. A rear wheel 15, which is a driving wheel, is rotatably supported at the rear end of the rear arm 13. The rear arm 13 is suspended from a body frame via a pair of left and right rear cushions 16. . Here, the details of the structure of the body frame are shown in FIG.
This will be described with reference to FIGS. 1 is a side view of the vehicle body frame, FIG. 2 is a plan view of the vehicle body frame, FIG. 3 is a partial front view of the vehicle body frame, FIG. 4 is an enlarged sectional view taken along line AA of FIG. 1, and FIG. 3 is an enlarged sectional view taken along line BB of FIG. 3, FIG. 6 is a side view of the rear arm bracket, FIG. 7 is a plan view of the rear arm bracket, FIG. 8 is a sectional view taken along line CC of FIG. 6, and FIG.
10 is a sectional view taken along line DD, FIG. 10 is a side view of the rear cushion bracket, FIG. 11 is a sectional view taken along line EE in FIG. 10, and FIG. 12 is a sectional view taken along line FF in FIG. As shown in FIGS. 1 and 2, the pair of left and right down tubes 6 is formed by three-dimensionally bending a single steel round pipe. After extending diagonally downward while expanding toward, it is bent and parallel to the rear, and extends horizontally, bent again and rises diagonally upward toward the rear, and its end is also a round pipe. The seat rail 17 is connected to a horizontal intermediate portion of the seat rail 17. As shown in FIG. 3, a portion of the down tube 6 close to the head pipe 1 is reinforced by a flat gusset 18, and a lower portion 6a thereof is flattened to avoid interference with the exhaust pipe 10. It is formed into an oval cross section (see FIG. 5). Also, two portions of the upper and lower engine mount bosses 1 are located below the flat portion 6a of the down tube 6.
9 are inserted and bound. On the other hand, the pair of left and right tank rails 5 is also formed of a round pipe made of steel, which branches off from the upper part of the head pipe 1 in a bifurcated manner and gradually extends obliquely downward toward the rear. The down tube 6 extends obliquely downward toward the rear while gradually increasing its width, and its end is connected to an intermediate position of the rising portion of the down tube 6. Since the diameter of the tank rail 5 is larger than that of the down tube 6, the portion 5a of the tank rail 5 close to the joint with the down tube 6 is flattened according to the diameter of the down tube 6, as shown in FIG. The large-diameter tank rail 5 is rationally bonded to the small-diameter down tube 6. A portion of the tank rail 5 close to the head pipe 1 is reinforced by a gusset 20, and a cross pipe 21 laid horizontally behind the gusset 20.
Is mounted with an air cleaner bracket 22. A pair of right and left engine mounting brackets 24 is attached to a cross pipe 23 that is laid horizontally on a portion of the tank rail 5 close to the joint with the down tube 6. A pair of left and right tension pipes 25 is provided between the tank rail 5 and the down tube 6, and the tank rail 5 and the down tube 6, and the down tube 6 and the tension pipe 25 are paired right and left. Gussets 26 and 27 respectively. still,
A tank bracket 28 is attached to an intermediate position of each tension pipe 25. On the other hand, the seat rail 17 is formed in a U-shape in plan view as shown in FIG. 2, and its front end is connected to the tank rail 5. And the seat rail 1
7 is reinforced by a cross pipe 29, to which a tank bracket 30, seat brackets 32 and 33, a rear fender bracket 34 and the like are attached. The pair of left and right rear arm brackets 12 are provided at the corners of the joint between the tank rail 5 and the down tube 6 as shown in FIG.
The rear arm bracket 12 will be described in detail with reference to FIGS. 6 to 9. Each of the rear arm brackets 12 is formed by a channel member having a U-shaped cross section obtained by press-forming a steel plate, and the periphery of the opening is welded to the tank rail 5 and the down tube 6 so that the rear arm bracket 12 is formed on the body frame. Installed. That is, as shown in FIG. 8, a short side opening end peripheral edge 12a of the rear arm bracket 12 is bent outward along the outer periphery of the tank rail 5 having an elliptical cross section, and the bent portion 12a of the tank rail 5 It is adhered and welded to the outer periphery. As shown in FIG. 9, the peripheral edge 12 b of the long side opening of the rear arm bracket 12 is bent outward along the outer periphery of the down tube 6, and the bent portion 12 b is adhered and welded to the outer periphery of the down tube 6. ing. In the rear arm bracket 12, the bent portions 12 a and 12 b correspond to the rear arm bracket 1.
2 may be formed at the same time as the U-shaped cross-section is press-formed, or may be formed after U-shaped press-forming. Each of the rear arm brackets 12
A press-formed portion (U-shaped portion) 12c of the periphery is cut out in a cutout circular shape, and a boss 35 for mounting a rear arm and a boss 36 for an engine mount are fitted and welded into the cutout. The rear arm 13 (see FIG. 13) is vertically rotatably supported by the pivot shaft 14 (see FIG. 13) supported by a pair of left and right rear arm bosses 35. On the other hand, as shown in FIG. 1, a pair of left and right rear-action brackets 3 each having a triangular shape in a side view is provided at a corner of a joint between the down tube 6 and the seat rail 17.
7, the construction and mounting details of the rear-action bracket 37 will be described with reference to FIGS. Each rear-action bracket 37 supports the upper end of the rear-action 16 (see FIG. 13). The rear-action bracket 37 has the same structure as the rear arm bracket 12 and is attached in the same manner. That is, each rear-action bracket 37 is constituted by a channel member having a U-shaped cross section obtained by press-forming a steel plate, and its opening side peripheral edge 37a has a down tube as shown in FIG. 6 is bent outward along the outer periphery of the opening 6, and the opening peripheral edge 37 b on the long side is formed as shown in FIG.
As shown in the figure, the bent portions 37a, 37b are welded in close contact with the down tube 6 and the seat rail 17, respectively. As described above, in this embodiment, since the channel member constituting the rear arm bracket 12 is obtained by press-forming an inexpensive steel plate, there is an advantage that the material and the manufacturing cost are reduced as compared with the conventional case. Can be Further, since the channel member forming the rear arm bracket 12 is formed in a U-shaped cross section, necessary and sufficient strength and rigidity are ensured due to its geometrical shape, and the structure is lightweight. The rear arm bracket 12 composed of this channel member is welded by bringing the opening peripheral edges 12a and 12b into close contact with the outer circumferences of the tank rail 6 and the down tube 5, respectively.
The rear arm bracket 12 has a necessary and sufficient mounting strength. Further, the periphery of each rear arm bracket 12
The rear arm is inserted into the cutout formed in the pressed part 12c.
Adopting a configuration in which the boss 35 for mounting
Therefore, part of the rear arm mounting boss 35 is
Exposed from the bracket 12, the periphery of the exposed portion (ridge line
Part) is welded, the welding length becomes longer, and the rear
The notch into which the arm mounting boss 35 is fitted is the rear arm
Formed into the press-formed part 12c with high rigidity of the bracket 12.
The mounting strength of the rear arm mounting boss 35
Is enhanced. As is apparent from the above description, according to the present invention, the rear arm bracket is attached to each of the pair of left and right rear arm brackets.
The arm mounting boss is inserted and fixed, and the rear arm mounting boss is
Arm by a pivot shaft inserted through
The front end of the rear arm bracket up and down
In the motorcycle frame structure that is supported,
The rear arm bracket is constituted by a channel member having a U-shaped cross section obtained by press-molding a plate material, and a peripheral edge of an open end thereof is welded to a corner of a pipe frame.
Pressed parts around the periphery of each rear arm bracket
A notch is formed in the rear arm, and the rear arm mounting button is formed in the notch.
As a result, the frame structure of the motorcycle, which is inexpensive and can secure necessary and sufficient strength and rigidity, can be obtained.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view of a body frame of a motorcycle. FIG. 2 is a plan view of a vehicle body frame of the motorcycle. FIG. 3 is a partial front view of a vehicle body frame of the motorcycle. FIG. 4 is an enlarged sectional view taken along line AA of FIG. 1; FIG. 5 is an enlarged sectional view taken along line BB of FIG. 3; FIG. 6 is a side view of a rear arm bracket. FIG. 7 is a plan view of a rear arm bracket. FIG. 8 is a sectional view taken along line CC of FIG. 6; FIG. 9 is a sectional view taken along line DD of FIG. 6; FIG. 10 is a side view of a rear cushion bracket. FIG. 11 is a sectional view taken along line EE of FIG. 10; FIG. 12 is a sectional view taken along line FF of FIG. 10; FIG. 13 is a side view of the motorcycle. [Description of Signs] 5 Tank rail (pipe frame) 6 Down tube (pipe frame) 12 Rear arm brackets 12a, 12b Periphery of opening of rear arm bracket 17 Seat rail

Claims (1)

(57) [Claims] [Claim 1] Each of a pair of left and right rear arm brackets
The rear arm mounting boss is inserted into and fixed to the rear arm.
The pivot shaft is inserted through and supported by the mounting boss.
Turn the front end of the gear arm up and down on the rear arm bracket.
The frame structure of a motorcycle that is freely supported
Oite, wherein the rear arm bracket, a plate material composed of a U-shaped cross section of the channel member obtained by press forming, welding Then preparative its open end peripheral edge corner portion of the pipe frame
Pressed parts around the periphery of each rear arm bracket
A notch is formed in the rear arm, and the rear arm mounting button is formed in the notch.
Frame structure of a motorcycle characterized in that it is fitted and welded .