JPH1086877A - Motorcycle frame structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To greatly reduce the number of welding processes so as to improve productivity and to reduce the number of equipment for welding so as to lower a cost when a head pipe and respective frame members are integrally connected together in a vehicle body frame front part in a frame structure for a motorcycle. SOLUTION: In the subject motorcycle, respective front end parts of a main pipe 12 and a down tube 13a are integrally connected to a steering head pipe 11 individually. The head pipe 11, the main pipe 12, and the down tube 13a are connected to each other via a frame connecting gusset 14 which is overlapped to the head pipe 11, the main pipe 12, and the down tube 13a along their side faces so as to be welded to them.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a frame structure for a motorcycle, and more particularly to a structure for connecting frame members near a steering head pipe which is a front portion of a body frame.

[0002]

2. Description of the Related Art In a motorcycle, in a semi-double cradle type or a diamond type body frame,
The main pipe and the front end of the down tube, which are arranged in the vertical direction of the head pipe, are integrally connected to the head pipe for pivoting the steering. In this case, each frame member ( Conventionally, for connection of the main pipe and the down tube, each frame member is welded to the head pipe and connected, and then gussets are welded and reinforced over the head pipe and each frame member. .

[0003]

In the conventional motorcycle frame structure as described above, in order to connect each frame member to the head pipe, each frame member itself is connected to the head pipe by welding. In addition to the step of welding, a separate step of welding each gusset for reinforcement is required separately, so that the number of steps is increased and welding work is troublesome, and a welding jig for welding each frame member to the head pipe is provided. Separately, a welding jig for welding the gusset is further required, which requires much equipment.

[0004]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a steering head pipe having a main pipe and a down tube each having a front end. Are integrally connected to each other, the head pipe, the main pipe, and the down tube are integrally connected to each other via a frame connecting gusset that is overlapped and welded over their side surfaces. It is characterized by having.

[0005] Further, in the motorcycle frame structure according to the first aspect, as described in the second aspect, the tension pipe integrally connected across the main pipe and the down tube, It is characterized by being welded to the frame connecting gusset without being directly welded to the down tube.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a motorcycle frame structure according to the present invention will be described below with reference to the drawings.

FIG. 1 shows the overall appearance of a motorcycle to which the frame structure of the present invention is applied, as viewed from the side. The motorcycle 1 has a headlight 2 and a speedometer 3 disposed thereon. The steering handle 5 for operating the front wheels 4 is largely extended upward without being covered with a cowling on the upper front surface of the steering wheel, and the rear of a water-drop type fuel tank 6 installed so as to straddle the body frame. A so-called American type motorcycle in which a stepped tandem seat 8 extending to above the rear wheel 7 is installed, and the engine body 9 is installed below the fuel tank 6 without being covered by a cowling. is there.

FIGS. 2 and 3 show a vehicle body frame of such a motorcycle 1. The vehicle body frame 10 is a semi-cradle type frame, and the components of the frame are connected by welding to be integrated. It was done.

That is, at the front of the body frame 10,
The front end of one main pipe 12 extended rearward and bent downward in the middle with respect to the head pipe 11 pivotally supporting the steering, and one large-diameter down tube 13a extended downward. Is connected via a frame connecting gusset 14, and a tension pipe 15 is connected across the main pipe 12 and the down tube 13a.

At the lower end of one large-diameter down tube 13a, a small-diameter down tube 1 which is divided into right and left and extends rearward.
3b, the lower end of the main pipe 12 and the rear end of each down tube 13b are connected to a frame connecting cross pipe 16 extending in the width direction of the vehicle body, as shown in FIG. And the cross pipe 16
The left and right backstays 1 extending diagonally upward and backward
7 are connected to each other.

In front of the middle bent portion of the main pipe 12, seat rails 18 which are divided into right and left and extend rearward are connected, respectively.
It is connected in the middle of each backstay 17,
Tubes 19 to which the mounting brackets 21 of the passenger footrests are welded are respectively connected to the left and right back stays 17 in the middle thereof.

The main pipe 1 is attached to the body frame 10 in which the respective components of the frame are integrally connected as described above.
2, a tank locking bracket 22 for locking a front portion of the fuel tank is provided.
8, a tank fixing bracket 23 for fixing the rear end of the fuel tank and locking the front end of the seat,
It is provided over the left and right seat rails 18.

A hollow gusset 24 having a hollow structure of a sheet metal is integrally provided at the connecting portion between the left and right seat rails 18 and the back stay 17 by welding. Hollow gusset 2
4, two front and rear cross tubes 25 are integrally fixed by welding, and a mounting bracket 26 for mounting the upper end of the rear cushion is provided across the two cross tubes 25.

Behind the hollow gusset 24, a rear bracket 27 for supporting the rear fender from above or mounting and fixing the rear part of the seat extends across the rear ends of the left and right back stays 17. It is provided.

In the vicinity of the lower end of the main pipe 12,
Above the frame connecting cross pipe 16, a hollow tubular pivot boss 28 for mounting a rear arm is integrally fixed with the main pipe 12 skewered in the width direction of the vehicle body. The pivot boss 28 and the main pipe 1 below the pivot boss 28 also serve to reinforce the mounting.
2, the engine mounting bracket 29 is welded.

Further, in addition to the brackets described above, the body frame 10 includes a bracket 31 for fixing the pivot shaft of the rear arm, a bracket 32 for mounting the regulator, a bracket 33 for mounting the engine, a bracket 34 for mounting the side stand, and a side cover. Brackets for mounting various components, such as mounting brackets 35 and 36, an air cleaner mounting bracket 37, and a main stand mounting bracket 38, are integrally fixed to appropriate portions of the vehicle body frame 10 by welding.

The vehicle body frame 10 formed as described above
On the other hand, as shown in FIG. 1, a steering portion provided with a steering handle 5 on the upper side and a front fork 41 on the lower side is left and right within a certain range by a steering head pipe 11 fixed to the upper end of the main pipe. The front wheel 4 is mounted on a lower end of a front fork 41 having a cushion portion.

One side of the front wheel 4 has a caliper 42 attached to the front fork 41 side.
a and a disk 42 attached to the wheel side of the front wheel
b, and a disc brake 42 consisting of
A front fender 43 is attached to the front fork 41 so as to cover the upper part of the front wheel 4 from above.

On the other hand, a pivot boss 28 fixed in a skewered state in the width direction of the vehicle body near the lower end of the main pipe 12 has a pivot shaft 30 longer than that shown in FIG.
Through the pivot shaft 30, the left and right front end portions 45a of the rear arm 45 are provided at the outer ends of both ends of the pivot boss 28, and a bush in which grease is applied between the shaft 30 and the front end portion 45a. Each is rotatably supported with an oil seal (both not shown) interposed therebetween.

Both ends of the pivot shaft 30 projecting outward from the front end 45a of the rear arm are connected to the respective pivot shaft support brackets 3 fixed to the left and right back stays 17.
1 and pivot shaft 30 (bolt)
Is fixed to the bracket 31 by nut tightening, and the outer end side of each rear arm front end portion 45a inserted into the pivot shaft 30 is a pivot shaft supporting bracket 3
Each of them is oil-sealed by a cover-like seal member 31a provided inside 1.

The rear arm 45 is formed by integrally connecting a plurality of constituent members by welding.
As shown in the figure, a front end 45 inserted into the pivot shaft 30 is provided.
a U-shaped pipe 45c at the rear end of the left and right rear arm bodies 45b having a
Are connected to each other, and a cross member 4
5d are connected, a connecting pipe 45e is connected to the right and left over the U-shaped pipe 45c and the cross member 45d, and a reinforcing pipe 45f is connected to the right and left connecting pipe 45e and the rear arm body 45b. Are connected to each other.

The rear arm 45 includes a cross member 4.
A mounting bracket 46 for mounting the lower end of the rear cushion is integrally fixed to 5d by welding, and a mounting bracket 47 for mounting the chain cover is integrally fixed to an appropriate location by welding. At the rear ends of the left and right rear arm bodies 45b, elongated holes 45g for adjusting the axles of the rear wheels so as to be adjustable are respectively opened. As shown in FIG.
A rear wheel 7 is mounted on the rear end of the vehicle.

FIGS. 2 and 3 correspond to the rear cushion lower end mounting bracket 46 of the rear arm 45. As shown in FIGS.
As described above, the two front and rear cross tubes 25 are integrally fixed to the left and right hollow gussets 24 by welding, respectively, and the rear cushion upper end mounting bracket 26 is provided over the two cross tubes 25. As a result, as shown in FIG. 8, the rear cushion 50 interposed between the body frame 10 and the rear arm 45
Upper end mounting bracket 26 on the body frame side (cross tube 25) and lower end mounting bracket 4 on the rear arm 45 side
6 and attached.

The motorcycle 1 in which the front wheel 4 and the rear wheel 7 are respectively installed on the body frame 10 as described above includes:
As shown in FIGS. 1 to 3, the fuel tank 6 is installed so as to straddle the main pipe 12 and the seat rail 13 and be positioned by the tank locking bracket 22 and the tank fixing bracket 23. The seat 8 is installed behind the fuel tank 6 and above the hollow gusset 24 so as to be positioned by the tank fixing bracket 23 and the rear bracket 27.

A rear fender 51 for covering the upper portion of the rear wheel 7 from above is provided with the back stay 17 and the rear bracket 2.
7, rear stays 52 are provided on the left and right sides of the vehicle body outside the rear fender 51 so as to be fastened together with the rear fender 51. A backrest mounting stay 53 for mounting the backrest 54 of the tandem seat 8 is provided so as to connect the two.

Then, below the rear portion of the rear stay 52,
A turn signal 55 is installed on each of the left and right sides.
The license bracket 57 for attaching the license plate and the license lamp 58 for irradiating the license plate are respectively installed on the lower surface of the rear part.

Below the fuel tank 6 between the front wheel 4 and the rear wheel 7, a main pipe 12 and down tubes 13a, 13
Parts such as the engine body 9 and the carburetor 60 and an air cleaner (not shown) are installed in a space surrounded by the b and the back stay 17. From the front side of the engine body 9, an exhaust pipe 61 is provided as shown in FIG. As shown in FIG. 9, the rear end is connected to a muffler 62 located on the right side of the rear wheel 7 after extending downward once and then extending rearward through the right side of the vehicle body as shown in FIG. .

On the other hand, on the left side of the vehicle body where the muffler 62 is not disposed, as shown in FIG. 1, a sprocket (not shown) of an output shaft protruding laterally from a transmission portion extending from the lower rear of the engine body 9 to the rear. And a sprocket 63 fixed to the hub of the rear wheel 7, a chain 64 for transmitting the rotational driving force of the engine body 9 to the rear wheel 7 is bridged.

As shown in FIG. 9, a driver's footrests 65 are provided on both sides of the vehicle body between the front wheel 4 and the rear wheel 7, as shown in FIG. A side stand 67 is installed, a brake lever 69 and a kick pedal 70 are installed on the right side of the vehicle body, and a passenger footrest 66 is installed on both sides of the vehicle body in front of the rear wheel 7 as shown in FIG. Behind the side stand 67, one center stand 71 is provided on both sides of the vehicle body.

Further, in the motorcycle 1 in which the components are installed as described above, the fuel tank 6 is provided with a meter cover 72 on which a fuel meter 73 is mounted, and a steering head pipe. A frame cover 74 covering the front side of the fuel tank 5 from the rear of the fuel tank 5 and a frame cover 75 covering both lower sides of the fuel tank 5 are provided.

At the lower side of the front of the tandem seat 8, two side covers 76 are provided so as to cover both sides of an air cleaner (not shown). Cover 77
And a cover 78 for covering the inside of the passenger footrest 66.
And the like are provided on both sides of the vehicle body, and a chain 64 provided between a sprocket (not shown) of the engine output shaft and a sprocket 63 of the rear wheel 7 is provided at the rear thereof.
A chain case 79 for covering the upper half of the rear arm 45 is provided on the left side of the vehicle body.

By the way, in the motorcycle 1 having the above-described structure, as described above, the front end of the main pipe 12 and the front end of the down tube 13a are provided at the front of the body frame 10 with respect to the steering head pipe 11. Are connected via a frame connecting gusset 14, and a tension pipe 15 is connected across the main pipe 12 and the down tube 13a.

That is, at the front of the body frame 10,
As shown in FIG. 10, the front end of the main pipe 12 is in contact with the head pipe 11 on the upper rear side, and the front end of the down tube 13a is in contact with the lower rear side. With no parts welded,
After the frame connecting gusset 14 is overlapped over the head pipe 11, the main pipe 12, and the down tube 13a, the periphery of the frame connecting gusset 14 is welded to the head pipe 11, the main pipe 12, and the down tube 13a. The head pipe 1
1, the main pipe 12, and the down tube 13a are integrally connected.

At that time, at the same time, the head pipe 11
The portion of the abutting portion of the main pipe 12 and the down tube 13a that is not covered by the frame connecting gusset 14 is also welded. As a result, the portion indicated by the mark x in FIG. The portion of the contact portion of the pipe 11, the main pipe 12, and the down tube 13a, which is covered by the frame connecting gusset 14, is not welded.

In addition to the frame connecting gusset 14, another reinforcing gusset 82 is welded over the lower side of the down tube 13a and the head pipe 11, and as shown in FIG. A holder 83 for holding a wire is provided over the frame connecting gusset 14 and the reinforcing gusset 82 on one side, and the welding is performed simultaneously during the welding operation of the frame connecting gusset 14. .

In this embodiment, the main pipe 12
Tension pipe 1 and the down tube 13a.
5, the tension pipe 15 is directly welded to the main pipe 12, but is merely in contact with the down tube 13a, and is not directly welded. The tube 13a is indirectly connected to the tube 13a by being welded to the frame connecting gusset 14.

As described above, according to the frame structure of the present embodiment in which the head pipe 11 and the frame members 12 and 13a are integrally connected via the frame connecting gusset 14, the head positioned on the jig is provided. By simply welding the frame connecting gussets 14 from both sides of the pipe 11 and the frame members 12, 13a, the head pipe 11 and the frame members 12, 13a are integrally connected and the gussets 14 are simultaneously attached during the same operation. be able to.

Therefore, the number of welding steps for the front part of the vehicle body frame can be greatly reduced, productivity can be improved, and the welding jig required for welding the front part of the vehicle body frame can be used for gusset welding. It is possible to reduce costs by reducing the number of facilities.

In the present embodiment, the frame connecting gusset 14 is connected to the tension pipe 1 without directly welding the frame members 15 and 13a to each other at the connecting portion between the tension pipe 15 and the down tube 13a.
5, the number of welding steps and welding jigs for the portion can be reduced.

Further, the tension pipe 15 is welded to a frame connecting gusset 14 at a middle portion of the tension pipe 15 near the down tube 13a, and the end of the tension pipe 15 on the down tube 13a side is free. Therefore, the manufacturing error of the vehicle body frame can be absorbed in the portion.

Since the tension pipe 15 is generally inclined forward and downward so that the down tube 13a is forward of the vehicle body, one end of the tension pipe 15 is welded to the frame connecting gusset 14. At this time, by welding the down tube 13a side, the frame connecting gusset 14 itself for welding the tension pipe 15 does not become unnecessarily large.

The frame structure of the motorcycle according to the present invention has been described above with reference to the embodiment using the body frame 10 of the semi-double cradle type provided with the tension pipe 15. It is needless to say that the present invention is not limited to the above-described embodiment, such as being applicable to a motorcycle.

[0043]

According to the motorcycle frame structure of the present invention as described above, when the head pipe and each frame member are integrally connected at the front portion of the body frame, the number of welding steps is greatly reduced. Therefore, the productivity can be improved, and the equipment for welding can be reduced, so that the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a side view showing the appearance of a motorcycle to which a frame structure according to the present invention is applied.

FIG. 2 is a side view showing a vehicle body frame of the motorcycle shown in FIG. 1;

FIG. 3 is a top view of the vehicle body frame shown in FIG. 2;

FIG. 4 is a top view showing a connection part of a main pipe, a down tube, and a back stay in the vehicle body frame shown in FIG. 2;

FIG. 5 is a top view showing a pivot portion of the rear arm in the motorcycle shown in FIG.

FIG. 6 is a side view showing a rear arm of the motorcycle shown in FIG. 1;

FIG. 7 is a top view of the rear arm shown in FIG. 6;

FIG. 8 is an explanatory side view showing an arrangement relationship and a mounting state of the rear cushion in the motorcycle shown in FIG. 1;

FIG. 9 is an explanatory top view showing an arrangement relationship of components installed on a lower portion of the vehicle body such as a muffler, a chain, and a side stand in the motorcycle shown in FIG. 1;

FIG. 10 is a side view of the front part of the vehicle body frame showing one embodiment of the frame structure of the present invention.

FIG. 11 is a sectional view taken along the line AA of FIG. 10;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Motorcycle 11 Steering head pipe 12 Main pipe 13a Down tube 14 Gusset for frame connection 15 Tension pipe

Claims (2)

[Claims] 1. A motorcycle in which respective front ends of a main pipe and a down tube are integrally connected to a steering head pipe, respectively, wherein the head pipe, the main pipe, and the down tube extend over their side surfaces. A motorcycle frame structure which is integrally connected to each other via a frame connection gusset which is overlapped and welded. 2. A tension pipe integrally connected across the main pipe and the down tube is welded to the frame connecting gusset without being directly welded to the down tube. 2. The frame structure of the motorcycle according to 1.