JPH1086880A - Rear arm shaft fitting part structure for motorcycle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To install a pivot boss for a motorcycle rear arm to a vehicle body frame with high strength and high rigidity, carry out installation of an engine mounting bracket and reinforcement of a connecting part between the vehicle body frame and the pivot boss at the same time in a single operation, and reduce the number of part items for installation of the pivot boss so as to reduce the installation space. SOLUTION: In the motorcycle, a rear arm front end part 45a is journalled to a vehicle body frame via an arranged pivot shaft 30. In this case, a pipe type pivot boss 28 for insertedly supporting the pivot shaft 30 is welded while penetrating a main pipe 12, while an engine mounting bracket 29 is welded over the pivot boss 28 and the main pipe 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rear arm mounting portion for mounting a front end portion of a rear arm having a rear wheel on a rear end portion thereof to a body frame of a motorcycle through a pivot shaft. Regarding the structure.

[0002]

2. Description of the Related Art In a motorcycle, the front ends of left and right rear arms are respectively pivoted via pivot shafts arranged in the vehicle body width direction near a lower portion in the front-rear direction center of a body frame, and rear ends of the respective rear arms are provided. The rear wheels are swingably mounted on the body frame via the rear arm by swingably mounting the rear wheels across the part. In this case, the front end of each rear arm with respect to the body frame Conventionally, a pivot shaft mounting bracket is integrally attached to the body frame on both the left and right sides of the vehicle body by welding, and the left and right pivot shaft mounting A pivot shaft is provided over the bracket, and the front ends of the respective rear arms are rotatably fitted to the pivot shaft.

[0003]

With respect to the above-described conventional rear arm shaft mounting structure of a motorcycle, the pivot shaft is installed only by the bracket for mounting the pivot shaft which is welded to the vehicle body frame on both sides of the vehicle body. Doing so only has a low rigidity to support the rear arm that swings around the front end, and in practice requires a large amount of reinforcement in that part, and as a result, a part for installing the pivot shaft As the number of points increases, the mounting space for them also increases.

[0004]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a vehicle body frame having a vehicle width in the vicinity of a lower portion at the center in the front-rear direction with respect to the vehicle body frame. In a motorcycle in which a front end of a rear arm is pivotally mounted via a pivot shaft arranged in a direction, a tubular pivot boss for inserting and supporting the pivot shaft is used to connect a main pipe of a body frame to a vehicle body width. The engine mounting bracket is welded to the main pipe while being pierced in the direction of the skewers, and the engine mounting bracket is welded over the pivot boss and the main pipe.

In the structure for attaching a rear arm shaft of a motorcycle according to the first aspect of the present invention, the left and right rear arms are provided outside the both ends of the pivot boss through which the pivot shaft is inserted, as described in the second aspect. The front ends of the pivot shafts are respectively inserted into the pivot shafts, and both ends of the pivot shafts outside the front ends of the rear arms are respectively fixed to left and right pivot shaft fixing brackets welded to the left and right back stays, respectively. It is characterized by having.

[0006]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a motorcycle according to an embodiment of the present invention.

FIG. 1 shows an overall appearance of a motorcycle to which a rear arm shaft attachment structure according to the present invention is applied, as viewed from the side. The motorcycle 1 includes a headlight 2.
The steering wheel 5 for operating the front wheels 4 is greatly extended upward without being covered with a cowling on the upper front surface of the steering wheel on which the speedometer 3 is disposed, and is installed so as to straddle the body frame. A stepped tandem seat 8 that extends to above the rear wheel 7 is installed behind the water droplet type fuel tank 6, and an engine body 9 is installed below the fuel tank 6 without being covered with a cowling. It is a motorcycle belonging to the so-called American type.

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. Are connected to each other in a state where they are reinforced by a frame connecting gusset 14, and a tension pipe 15 is connected to 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 separated to the left and right 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, between the shaft 30 and the front end portion 45a. Each is rotatably supported by a shaft 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 according to the present embodiment having the above-described structure, as described above, the rear arm mounting portion is provided above the frame connecting cross pipe 16 and near the lower end of the main pipe 12. Pivot boss 2
8 are integrally welded in a state where the main pipe 12 is skewered in the width direction of the vehicle body, and a pivot shaft 30 is inserted through the pivot boss 28.

For this reason, the pivot boss 28 is integrally fixed to the highly rigid main pipe 12 without particularly requiring a bracket for attaching the pivot boss 28, and the mounting space for the pivot boss 28 is large. In addition, the pivot shaft 30 is widely and securely supported by the pivot boss 28.

The pivot boss 28 and the main pipe 1
2, the engine mounting bracket 29 is welded, so that the main pipe 12 and the pivot boss can be used without using a special reinforcing member and using the engine mounting bracket 29, which is a member used for other purposes. 28 is further reinforced, and the engine mounting bracket 2
9 and the reinforcement of the joint between the pivot boss 28 and the main pipe 12 are simultaneously performed by a single welding operation.

Further, in this embodiment, both ends of the pivot shaft 30 projecting outward from the rear arm front end 45a are fixed to the left and right back stays 17 via the respective pivot shaft support brackets 31. That is, since both ends of the pivot shaft 30 whose center is supported by the pivot boss 28 fixed with high rigidity are further fixed to the respective back stays 17, the pivot boss 28 is inserted into the pivot shaft 30. Front end 45a of each rear arm
Are supported with high rigidity to the body frame.

[0036]

According to the structure for attaching the rear arm shaft of the motorcycle according to the present invention as described above, the pivot boss supporting the pivot shaft of the rear arm can be attached to the body frame without requiring any special mounting member or reinforcing member. It can be installed with high strength and high rigidity, and the pivot shaft can be widely supported by the pivot boss,
In addition, the mounting of the engine mounting bracket and the reinforcement of the joint between the body frame and the pivot boss can be performed simultaneously in one operation, and the number of parts for mounting the pivot boss is reduced, and the mounting space is reduced. Thus, the degree of freedom in layout of other components in the portion can be increased.

[Brief description of the drawings]

FIG. 1 is a side view showing an appearance of a motorcycle to which a rear arm shaft attachment 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 partial cross-sectional top view of the rear arm shaft attaching portion, showing one embodiment of the rear arm shaft attaching portion structure of the present invention.

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;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Motorcycle 10 Body frame 12 Main pipe 17 Backstay 28 Pivot boss 29 Engine mounting bracket 30 Pivot shaft 31 Pivot shaft fixing bracket 45 Rear arm 45a Rear arm front end

Claims (2)

[Claims] 1. A motorcycle in which a front end of a rear arm is pivotally mounted on a vehicle body frame via a pivot shaft disposed in a width direction of the vehicle near a lower portion in the center of the vehicle body in the front-rear direction. A tubular pivot boss for supporting and supporting the main pipe of the vehicle body frame is welded to the main pipe in a state of penetrating the main pipe in the width direction of the vehicle body in a skewered manner, and the engine is extended over the pivot boss and the main pipe. A mounting structure for a rear arm shaft of a motorcycle, wherein a mounting bracket is welded. 2. The front ends of the left and right rear arms are respectively fitted to the pivot shafts at both ends of the pivot boss through which the pivot shafts are inserted, and both ends of the pivot shafts outside the front ends of the respective rear arms. The rear arm shaft attachment portion structure for a motorcycle according to claim 1, wherein the left and right pivot stays are respectively fixed to left and right pivot shaft fixing brackets.