JPH10129560A - Body frame for motorcycle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the body frame for a motorcycle, where the combination of a head pipe with main pipes, which consist of the main member of the body frame, are facilitated without being adversely affected by the heat of welding. SOLUTION: In the car body frame of a motorcycle, a head pipe part 2 pivotally supporting the rotating shaft of a handle in such a way as to let it be freely rotatable, is formed out of casting, main pipe parts which are connected with the head pipe 2 so as to be extended afterward, are made out of dissimilar material, and both of the parts are combined with each other so as to be formed into a main member 1. In this case, the tip end part of each main pipe part 3 is integrally formed into internal chill together with a joint member 8, and the joint member 8 is thereby combined with the head pipe part 2 by means of bolt fastening thereafter.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motorcycle body frame, and more particularly, to a method for connecting a head pipe and a main pipe constituting a main member of the frame by eliminating the influence of heat caused by welding. Automatic 2 for easy operation
The present invention relates to a body frame of a wheeled vehicle.

[0002]

2. Description of the Related Art As a body frame of a conventional motorcycle,
Some are shown in FIG. In this one,
The head pipe portion 02 and the pivot plate portion 04 are formed by casting, the main pipe portion 03 is formed by extrusion molding of different members, and these are set in a welding jig, and the head pipe portion 02 and the main pipe portion 03 are formed. Are connected by welding at a part a in the drawing, and the pivot plate part 04 and the main pipe part 03 are connected at a part b in the drawing by welding, respectively.
The main part of the body frame is configured.

[0003] Another conventional motorcycle body frame is disclosed in JP-A-4-55185 and JP-A-4-5185.
There is one described in Japanese Patent No. 5186. In these components, each component (each pipe component) constituting the vehicle body frame has an engaging portion at a connecting portion between these components, and the engaging portion is fixed by an adhesive or a bolt. The vehicle body frame is configured by being fixed to the components.

[0004]

However, FIG.
In the prior art shown in FIG. 1, since the components constituting the body frame of the motorcycle are connected by welding, the material strength is reduced by the influence of heat, and the dimensional accuracy is reduced by thermal distortion. There is a problem of deterioration, and the quality of welding is difficult to stabilize, hand correction is necessary after welding,
A great deal of labor was required for finishing work after welding, such as the need to remove spatter. Further, the portion of the vehicle body frame constituted by the combination of the components described above is often a portion exposed to the outside, and therefore, the welding of the connection portion needs to be performed so as not to impair the aesthetic appearance. There was a need for skill in the welding work. By these,
Manufacture of body frames was expensive.

[0005] Further, in the prior art described in each of the above publications, the above-mentioned problems do not occur because the components constituting the body frame of the motorcycle are not connected by welding. However, since there is an engaging portion interposed between the components, there is a problem that the structure is complicated, the strength is weakened, and the appearance productability is impaired.

[0006]

SUMMARY OF THE INVENTION The invention of the present application is a vehicle body frame of a motorcycle which solves such a problem, and the invention described in claim 1 is such that the handle rotation shaft is rotatable. A motorcycle body in which a head pipe portion is formed by casting, and a main pipe portion connected to the head pipe portion and extending rearward is formed of dissimilar members, and these two portions are joined to form a main member. A body frame for a motorcycle, wherein a front end portion of the main pipe portion is cast-integrated with a joint member and then the joint member and the head pipe portion are bolted to each other.

According to the first aspect of the present invention, a joint member is used to connect the head pipe portion and the main pipe portion, and the joint member is connected to the main pipe portion. It is integrated by casting the tip of the part, and it is firmly connected to the head pipe part by bolt connection, simplifying the structure, improving the appearance and productability, and maintaining the strength Is done. Further, since welding is not performed, the work time before and after welding, which has been conventionally performed for welding, is saved, so that the work time is reduced as a whole, and the manufacturing cost is reduced. Furthermore, the problem of a decrease in material strength due to the influence of welding heat and a decrease in dimensional accuracy due to thermal distortion is eliminated, and the quality is stabilized.

[0008] Further, according to the first aspect of the present invention, the main pipe portion is prevented from coming off from the joint member after casting.

[0009]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a first embodiment of the present invention; FIG. In these drawings, the body frame of the motorcycle includes a head pipe portion 2 rotatably supporting a handlebar rotation shaft, and a pair of left and right main pipe portions 3 connected to the head pipe portion 2 and extending rearward. These are combined to form a main member 1, and a pair of left and right pivot plate portions 4 extending substantially in the vertical direction are connected to the rear of the main pipe portion 3.

The head pipe portion 2 is usually formed by casting using an aluminum material. A hole 6 through which a handle shaft (not shown) is inserted is formed at the front of the head pipe portion 2. The end portions 15 of the pair of left and right main pipe portions 3 are joined to the surface 7 (only the left surface is shown) in a manner described later.

The main pipe 3 is usually made of an aluminum material different from the head pipe 2 as shown in detail in FIGS. The straight pipe 9 obtained by extrusion molding into a square shape is bent, and a plurality of concave portions (retaining portions) 10 are formed by embossing on both side surfaces of both end portions 15 and 16, and caps are formed on both ends. 11 is formed by press-fitting and capping. In addition, the main pipe part 3 shown in these figures
Is used on the left side of the vehicle body, and the main pipe section 3 used on the right side of the vehicle body is formed symmetrically to the one shown in FIG.

Further, the pivot plate portion 4 is located at a substantially central portion of the vehicle body frame, a front end portion of a rear frame (not shown) is provided at a rear portion thereof, and a bridge such as a cross pipe 5 is provided at upper and lower portions thereof. The ends of the part are connected,
It serves to connect all the components of the body frame to one integrated structure, and has a connecting portion 12 which forms a connecting portion with the rear end portion 16 of the main pipe portion 3 at an upper front portion thereof.
Are formed. Then, the pivot plate portion 4
Also, it is formed by casting using the same material as the head pipe portion 2. 17 are holes formed at the upper and lower portions of the pivot plate portion 4 and through which bolts are inserted together with holes 18 at the ends of the upper and lower cross pipes 5. Bolts are inserted into these holes, and nuts are inserted into the bolts. By being screwed, the upper and lower cross pipes 5 are connected to the pivot plate portion 4.

Next, a method of connecting the head pipe 2 and the left main pipe 3 configured as described above will be described. First, as shown in FIG. 10, the left main pipe portion 3 formed as described above is
The tip 15 is set in a mold space 19 for forming a joint member 8 to be described later, and the rear end 16 is set in the left pivot plate 4 to form a left pivot plate 4. Projecting into the mold space 20. A substantially central portion of the left main pipe portion 3 is exposed outside the mold.

Next, in the mold space 19 and the mold space 20,
When the casting water is poured, the joint member 8 and the left pivot plate portion 4 are formed, and at the same time, the joint member 8 and the left pivot plate portion 4 form the front end portion 15 and the rear end portion 16 of the left main pipe portion 3. After casting the solidified cast metal, remove these from the mold,
One in which the joint member 8 and the left pivot plate 4 are formed integrally with the left main pipe 3 (left subframe) is obtained. Here, the joint member 8
A plurality of bolt insertion holes 22 are formed at positions corresponding to screw holes 21 formed in the left side surface 7 of the head pipe portion 2 described later. Also, the left pivot plate 4
The hole 17 for inserting the bolt is formed in the upper and lower portions of the hole. These holes 22 and holes 17 may be formed by machining after casting.

Then, a head pipe 2 and a right pivot plate 4 are formed integrally with the right main pipe 3 (right subframe) by the same method (see FIG. 1). For this purpose, the above-mentioned mold is a symmetrical mold, and only the mold space 19 for forming the joint member 8 is replaced by a mold space (not shown) for forming the head pipe portion 2. Using,
The same may be performed. In the left side surface 7 of the head pipe portion 2, after casting, a screw hole 21 into which a screw portion of a bolt having a required diameter is screwed into a position corresponding to the bolt insertion hole 22 of the joint member 8. Is formed.

The hole 22 formed in the joint member 8 of the left sub-frame manufactured as described above is
If the bolt is screwed into the screw hole 21 from the hole 22 side by matching with the screw hole 21 formed in the head pipe part 2 of the right sub-frame, the head pipe part 2 and the left main pipe part 3 are joined. It will be. In addition, the head pipe 2 and the left and right main pipes 3, 3 are thereby integrally connected.

In order to integrally connect the left pivot plate portion 4 and the right pivot plate portion 4, a cross pipe 5 is interposed between the two and a hole 18 of the cross pipe 5 is provided.
And a hole 17 of the pivot plate portion 4 and a nut is screwed onto the bolt.

In the present embodiment, the joint member 8 is used for connecting the head pipe 2 and the left main pipe 3 because it is configured as described above.
The joint member 8 is integrated by casting a tip end portion 15 of the main pipe portion 3 and is firmly connected to the head pipe portion 2 by bolting, so that the structure is simplified, In addition to improving the appearance of the product, the strength is maintained. In addition, since welding is not performed, the work time before and after welding, such as mounting on a welding jig and removing spatter, which has been conventionally performed for welding, is saved, and the work time as a whole is shortened. Costs are reduced. Furthermore, the problem of a decrease in material strength due to the influence of welding heat and a decrease in dimensional accuracy due to thermal distortion is eliminated, and the quality is stabilized.

Furthermore, the tip 15 of the left main pipe 3
As described above, the concave portions 10 are formed on both side surfaces of the rear end portion 16.
When casting with the left pivot plate portion 4, casting water is introduced into the concave portion 10, and after the casting metal is solidified, the joint member 8 and the left pivot plate portion 4 come out of both ends of the left main pipe portion 3. Is prevented (FIG. 9).
reference).

In the above embodiment, the hole 22 formed in the joint member 8 is matched with the screw hole 21 formed in the head pipe 2 to connect the head pipe 2 and the left main pipe 3. Was carried out by screwing a bolt into the screw hole 21 from the side of the hole 22, but replacing the screw hole 21 with a bolt insertion hole, applying a nut from the back, and connecting the bolt and nut with a screw connection You may.

As shown in FIG. 12, instead of the concave portions 10 formed at both ends of the left main pipe portion 3,
The plug (projection) 23 may be welded and used as a retaining portion. Alternatively, as shown in FIGS. 13 and 14, a hole is formed at the position of the concave portion 10, and a rivet 24 is inserted through the hole and swaged to form a convex portion on the cast-in surface. May be used as a retaining portion.

Furthermore, the tip 14 of the left main pipe 3
As shown in FIGS. 15 and 16, grooves 25 are formed on the upper and lower surfaces of the rear end portion 15, and when these portions are cast with the joint member 8 and the left pivot plate portion 4, Also, the casting metal is introduced so that the joint member 8 and the left pivot plate portion 4
It may be designed to reinforce the connection between the left main pipe 3 and both ends of the left main pipe 3.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a body frame of a motorcycle illustrating an embodiment of the invention described in claims 1 and 2 of the present application.

FIG. 2 is a perspective view of a main pipe portion material in a straight pipe state obtained by extrusion molding in the embodiment of FIG. 1;

FIG. 3 is a perspective view of a main pipe part material obtained by bending the main pipe part material of FIG. 2;

FIG. 4 is a perspective view of a main pipe material obtained by embossing both ends of the main pipe material of FIG. 3;

5 is a perspective view of a finished product of the main pipe part in which caps are covered at both ends of the main pipe part material of FIG. 4;

FIG. 6 is a perspective view of a left sub-frame in which both ends of a main pipe portion of FIG. 5 are formed by a joint member and a left pivot plate portion.

7 is a cross-sectional view taken along line VII-VII of FIG. 4, showing a retaining portion (recess) formed at the tip of the main pipe portion.

8 is a cross-sectional view taken along the line VIII-VIII of FIG. 5, showing a retaining portion (recess) formed at the tip of the main pipe portion and a cap covered by the portion. .

FIG. 9 is a cross-sectional view taken along line IX-IX of FIG. 6, showing a state in which a tip end of a main pipe portion is cast with a joint member.

FIG. 10 is a view showing a step of casting both ends of the main pipe section of FIG. 5 by a joint member and a left pivot plate section, and is a view showing a state before casting.

FIG. 11 is a view showing another step of casting both ends of the main pipe section of FIG. 5 by the joint member and the left pivot plate section, and is a view showing a state after casting.

FIG. 12 is a view showing another embodiment of the retaining portions formed at both ends of the main pipe portion.

FIG. 13 is a view showing still another embodiment of the retaining portions formed at both ends of the main pipe portion.

FIG. 14 is a sectional view taken along line XIV-XIV in FIG.

FIG. 15 is a perspective view of another embodiment showing a state in which the tip of the main pipe section of FIG. 5 is cast with a joint member.

FIG. 16 is an enlarged sectional view taken along line XVI-XVI of FIG. 15;

FIG. 17 is a perspective view of a body frame of a conventional motorcycle.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Main member, 2 ... Head pipe part, 3 ... Main pipe part, 4 ... Pivot plate part, 5 ... Cross pipe, 6 ...
Hole, 7: Surface, 8: Joint member, 9: Straight pipe (main pipe part material), 10: Recess, 11: Cap, 12: Connection,
13 ... upper mold, 14 ... lower mold, 15 ... front end, 16 ... rear end, 17 ...
Hole, 18 ... Hole, 19 ... Mold space, 20 ... Mold space, 21 ... Screw hole, 22 ... Hole, 23 ... Plug (protrusion), 24 ... Rivet, 25 ...
groove.

Claims (2)

[Claims] 1. A head pipe portion for rotatably supporting a handle rotating shaft is formed by casting, and a main pipe portion connected to the head pipe portion and extending rearward is formed of a dissimilar member, and these two portions are joined. In the motorcycle body frame as a main member, the front end portion of the main pipe portion is cast-integrated with a joint member, and then the joint member and the head pipe portion are bolted to each other. Body frame for motorcycles. 2. The automatic pipe machine according to claim 1, wherein a concave portion or a convex portion is formed at a tip portion of said main pipe portion to form a retaining portion by introducing casting water at the time of casting.
Body frame of wheeled vehicle.