JP3522296B2 - Motorcycle frame structure - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motorcycle having a motorcycle in which a main pipe branches rearward from a head pipe and a main pipe extends rearward. 2. Description of the Related Art Many motorcycles have this kind of frame structure, and FIG. 1 shows a general example of the related art in the vicinity of a head pipe. That is, a pair of left and right main pipes 02 extend rearward from the left and right side surfaces of the upper part of a cylindrical head pipe 01 provided with bearing portions 01a and 01b vertically. Similarly, a pair of left and right down pipes 03 extends downward from the left and right side surfaces of the lower part of the head pipe 01, and a reinforcing pipe 05 is interposed between the cross pipe 04 and the down pipe 03 provided between the pair of left and right main pipes 02. Is equipped. [0004] The ends of the main pipe 02 and the down pipe 03 are butt-welded to the head pipe 01 and are joined. However, since the head pipe 01 rotatably supports a front fork for supporting the front wheel, the front wheel is provided. Due to the load generated between the head pipe 01 and the ground, an excessive bending moment is applied to the upper and lower joints of the head pipe 01. Therefore, the head pipe 01 and the main pipe
An upper gusset 06 and an under gusset 07 are later welded to the joint portion with 02 and the joint portion between the head pipe 01 and the down pipe 03 for reinforcement. Further, the center gusset 08 may be welded over the head pipe 01, the down pipe 03, and the reinforcing pipe 05. There is an example in which a frame member mounting portion is integrally formed with a head pipe (Japanese Utility Model Laid-Open No. 15686/1986), but the gusset portion becomes large. As described above, the conventional general frame structure has a structure in which a main pipe 02 and a down pipe 03 are first connected to a head pipe 01, and then an upper gusset 0 is formed.
6, since the under gusset 07 and the center gusset 08 are welded, a joining jig is required for each process, and the joining process is dispersed, for example, the number of times of attachment / detachment to the jig increases. As a result, the production efficiency is poor, leading to an increase in cost, and the capital investment for jigs also increases. SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object thereof is to provide a small and lightweight frame structure of a motorcycle which can easily perform a connecting operation with a small number of connecting jigs. [0008] In order to achieve the above object, the present invention provides a pair of left and right main pipes extending from left and right sides of a cylindrical head pipe having upper and lower bearings. In a motorcycle having a frame structure in which a gusset reinforces a joint with the head pipe while extending rearward while spreading to the gusset, the gusset has a central portion welded to a rear side surface of the head pipe, and A fan-shaped portion having left and right side portions extending diagonally to the left and right while extending in the left and right width direction, and connecting upper end edges and lower end edges of the left and right side portions to extend substantially radially from the central portion; The central part, the upper part, the lower part, and the right and left side parts are formed integrally around a space opened rearward, and are opened outside the upper part of the left and right side parts . A pair of left and right The motorcycle has a motorcycle frame structure in which the main pipe is applied from the outside and welded. The gusset is joined to the head pipe at the center thereof, and the main pipe is applied from the outside to the place where the gusset is assembled and welded, so that the main pipe can be positioned by the left and right side pieces of the gusset. Since the number of jigs is small, the joining operation is simplified, and the production efficiency can be increased. A gusset is formed separately from the head pipe
The gusset is welded to the rear side of the head pipe.
Center part, left and right sides where the main pipe is applied from the outside
The upper edge and the lower edge of the left and right sides are connected
The upper and lower pieces are formed integrally around the space opened backward.
The box side, so it is necessary to secure structural rigidity.
To make the gusset thicker than necessary
It is possible to reduce the size and weight without the need. An embodiment of the present invention shown in FIGS. 2 to 9 will be described below. FIGS. 2 and 3 are a side view and a plan view showing the entire frame structure of the motorcycle according to the present embodiment. A pair of left and right main pipes 2 is formed from the upper left and right side surfaces of a cylindrical head pipe 1 having upper and lower bearing portions 1a and 1b.
Extend rearward and diagonally slightly downward while spreading in the width direction. A pair of left and right down pipes 3 extend obliquely downward from the lower left and right side surfaces of the head pipe 1. The main pipe 2 and the down pipe 3
A gusset 4 integrally press-formed is welded and reinforced at a portion connected to the head pipe 1. Cross pipes 5 and 6 are provided between the left and right main pipes 2, and a reinforcing pipe 7 is interposed between the front cross pipe 5 and the left and right down pipes 3. A rear end of the main pipe 2 is connected to a center frame 8 which is continuously provided downward, a seat rail 9 is connected rearward, and a back stay 10 for reinforcing the seat rail 9 is provided with a seat rail 9. Is interposed below the center frame 8. FIG. 4 shows in detail the shape of the gusset 4 used in the coupling structure around the head pipe 1 in such a body frame structure. That is, the gusset 4 has a central concave portion 4a in the center of which a circumferential concave surface is formed corresponding to the rear side surface of the head pipe 1, and the right and left side pieces 4b extend rearward while spreading in the left and right width direction from the central portion 4a. At the same time, the upper edge of the left and right side pieces 4b is connected to form a fan-shaped upper piece 4c, and the lower edge is connected to form a lower piece 4d. As a whole, the pieces 4b, 4c, 4d are substantially radially formed from the central recess 4a. It is extended and formed as a whole by press working. The left and right side pieces 4b are symmetrical and open to the outside of a semi-cylinder into which the front end of the main pipe 2 abuts.
A semi-cylindrical convex portion 4f is formed at the lower end of the concave portion 4e and in contact with the front end of the down pipe 3 to form a smooth wavy shape as a whole. A reinforcing plate 20 is provided between the left and right side pieces 4b. The joining procedure around the head pipe using the gusset 4 will be described. First, as shown in FIG. 5, the central recess 4a of the gusset 4 is applied to the rear side surface of the head pipe 1 by welding. FIGS. 6 and 7 are views in which the gusset 4 is connected to the head pipe 1 to form a small assembled state. The main pipe 2 and the down pipe 3 are applied to the head pipe structure thus assembled from the outside of the gusset 4. The front end of the main pipe 2 is obliquely flattened on the inner side and abuts against the recess 4e of the side piece 4b of the gusset 4, and the front end is abutted against the head pipe 1 so that the inner flat part and a part of the circumferential surface are gusseted. Are positioned in contact with the concave portions 4e, and are welded and connected to each other (see FIGS. 8 and 9). On the other hand, a front end of the down pipe 3 is fixed to a contact metal 3a which is cut obliquely on the inside and curves into a cut to form a part of a cylinder. Is welded from outside and joined. After welding the main pipe 2 and the down pipe 3 to the head pipe 1 in which the gussets 4 are assembled as described above, the frame body is removed from the jig, and the connection work around the head pipe 1 is completed. . The left and right pieces 4b of the gusset 4 are provided with a concave portion 4e and a convex portion 4f for setting the main pipe 2 and the down pipe 3, respectively.
Is provided, the positions of the main pipe 2 and the down pipe 3 are determined, the gusset 4 itself serves as a jig, and the connecting jig itself can be simplified. Conventionally, an upper gusset, an under gusset, and a center gusset were welded to a plurality of gussets. However, in this embodiment, since the gussets are integrated,
The joining work is reduced, and the main pipe 2 and the down pipe 3 are applied from the outside to the place where the gusset 4 is assembled into the head pipe 1 and welded, so the joining work is easy and the attachment and detachment to the jig is small. The whole can be simplified, the production efficiency can be improved, and the cost can be reduced. Also, the number of jigs is small and the capital investment is minimal. In the gusset 4 of this embodiment, the portion to which the down pipe 3 is welded is formed as a convex portion 4f. On the contrary, as a concave portion, the front end of the down pipe 3 is abutted against the head pipe 1 to be similar to the main pipe 2. May be welded. In the above embodiment, the gusset 4 is formed integrally by press working. However, the gusset 4 may be integrally formed by casting, and examples thereof will be described with reference to FIGS. The head pipe 30 has upper and lower bearing portions 30a and 30b as in the previous embodiment, and has a structure in which the cylindrical portions 30c are connected to each other.
31 is a symmetrical shape and has a central portion along the head pipe 30.
The left and right side pieces 31b extend rearward from the 31a in the width direction.
Extends, and has a fan-shaped upper piece 31c by connecting the upper edges of the left and right pieces 31b, and a lower piece 31d by connecting the lower edges thereof. As a whole, each piece 31b, 31c, 31d starts from the central portion 31a. It extends substantially radially. The left and right side pieces 31b are composed of upper and lower two concave portions 31e and 31f obtained by dividing a cylinder in half. A central portion 31a between the base ends of the concave portions 31e and 31f has a U-shaped cross section. Open end
31 g abuts on the cylindrical portion 30 c of the head pipe 30 and is welded and joined. In addition, the central part 31a of the gusset 31 is the head pipe 30
The upper piece 31c and the lower piece 31 which are separated from the upper and lower parts and expanded in a fan shape
The base ends 31h and 31i of d are the upper and lower bearing portions 30 of the head pipe 30.
a, 30b and are welded together. As described above, the main pipe and the down pipe are connected to the upper and lower concave portions 31e and 31f where the gussets 31 are welded and integrally joined to the head pipe 30 at the upper and lower base ends 30a and 30b and the central opening end 31g. And the front end is abutted against the head pipe 30 and welded. As described above, the gusset 31 integrally manufactured by casting can be used, and the joining operation can be simplified and the production efficiency can be increased as in the above-described embodiment. According to the present invention, an integrated gusset having side pieces extending from the center to the left and right is welded to the head pipe, positioned at the side pieces, and the main pipe is applied and welded. Therefore, the number of jigs is small, the joining operation is simplified, the production efficiency can be improved, the cost can be reduced, and the capital investment can be reduced.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view showing a structure around a conventional head pipe. FIG. 2 is a side view showing a vehicle body frame structure of the motorcycle according to one embodiment of the present invention. FIG. 3 is a plan view of the same. FIG. 4 is a perspective view of the gusset of the present embodiment. FIG. 5 is a side view immediately before coupling a gusset to a head pipe. FIG. 6 is a side view showing a state where a gusset is welded to the head pipe. FIG. 7 is a view taken in the direction of arrow VII in FIG. 6; FIG. 8 is a side view showing a state in which a main pipe and a down pipe are welded to a head pipe to which a gusset is connected. 9 is a sectional view taken along line IX-IX in FIG. FIG. 10 is a side view showing a state where a gusset is coupled to a head pipe of another embodiment. 11 is a view taken in the direction of the arrow IX in FIG. 10; FIG. 12 is a view on arrow XII in FIG. 10; [Description of Signs] 1 ... Head pipe, 2 ... Main pipe, 3 ... Down pipe, 4 ... Gusset, 5,6 ... Cross pipe, 7 ... Reinforcement pipe, 8 ... Center frame, 9 ... Seat rail, 10 ...
Backstay 20: reinforcement plate, 30: head pipe, 31: gusset.

   ────────────────────────────────────────────────── ─── Continuation of front page    (72) Inventor Takehei Yokota               Stock 1-4-1, Chuo, Wako-shi, Saitama               Inside Honda Technical Research Institute                (56) References JP-A-60-56688 (JP, A)                 Japanese Utility Model Application No. 58-171995               84387) and the specification attached to the application               Microfilm of the contents of the drawing               (JP, U)                 Japanese Utility Model Application No. 63-53810               No. 157089) and the specification attached to the application               Microfilm of the contents of the drawing               (JP, U)

Claims (1)

(1) A pair of left and right main pipes extend rearward from left and right side surfaces of a cylindrical head pipe having upper and lower bearings while extending in the left and right width direction. A motorcycle having a frame structure in which a gusset reinforces the joint of the gusset, the gusset has a central portion welded to a rear side surface of the head pipe, and extends from the central portion in a laterally obliquely rearward direction while extending in a lateral width direction. The upper and lower edges of the left and right side portions are connected to each other, and the upper and lower edges are connected to each other to have a fan-shaped upper and lower pieces extending substantially radially from the central portion. central, upper piece, lower piece, part lateral side pieces are formed integrally surrounds a space which is open to the rear, on the left and right side sections
A frame structure for a motorcycle, wherein a pair of left and right main pipes are applied from outside to a concave portion opened to the outside of the portion and welded to each other.