JP3167487B2 - Motorcycle body frame - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to motorcycle body flexure.
About the game .

[0002]

2. Description of the Related Art Conventionally, it is known to use a cast product made of a light alloy as a body frame member of a motorcycle. For example, in a motorcycle body frame disclosed in Japanese Patent Application Laid-Open No. 1-254479, a front part is known. The vehicle body frame is constructed by assembling left and right halves each having a symmetrical shape that is separately cast.

Each half has a head pipe portion, a main frame pipe connected to the head pipe and extending rearward of the vehicle body, and an engine support pipe extending close to the head pipe and connected to the main frame pipe and extending downwardly of the vehicle body. These left and right halves are integrally welded at the head pipe part, and the front and rear halves are formed at the rear half.
The front body frame is assembled by fitting and welding both ends of the horizontal frame pipe of the book to the openings or holes of the respective halves.

The publication also discloses a casting mold and a casting method for casting the front body frame half, and the casting mold has a long shape corresponding to the front body frame half. A cavity, a long runway extending along the lower side of the cavity, a plurality of weirs connecting the runner to the cavity, and a spout connected to one end of the runner via a pool. A plurality of deaeration passages communicating with the upper part of the cavity are formed.

At the time of casting, the mold is placed so that the cavity and the runner are inclined vertically in the longitudinal direction with the sprue facing upward, and in this state, the molten metal is poured from the upper sprue. By doing so, the molten metal is hardly disturbed in the cavity, the communication of the deaeration passage is ensured until the completion of casting, and the generation of residual air bubbles in the product is prevented.

[0006]

By the way, the above-mentioned cast member, that is, the front body frame half, is welded to the rear frame pipe at the rear portion thereof, so that good weldability is required at this portion. In this portion, an opening for fitting a horizontal frame pipe, a mounting portion for a rear fork or a footrest member, and the like must be formed, so that good formability is required.

On the other hand, since the front part of the front body frame half is not reinforced by the horizontal frame pipe, a relatively large strength is required for this part, and the required functions differ between the front part and the rear part. There is. However, according to the conventional casting method, since the entire member is formed of a material of the same composition poured from the same gate, different portions of required functions are formed of materials of components suitable for each function, Effective use of materials and improvement of quality cannot be achieved.

Accordingly, the present invention provides a material for a front part and a rear part.
Ingredients meet the functions required for each part, and do not significantly change the conventional casting process and equipment,
Therefore, casting can be performed without requiring new capital investment
An object of the present invention is to provide a body frame of a motorcycle .

[0009]

SUMMARY OF THE INVENTION Therefore, the present invention is directed to a head pipe rearward from a head pipe.
A pair of main frames extending left and right, and the pair of main frames
Cross pipe welded to the rear part of the
A motorcycle body frame comprising:
A frame is located in a casting mold, with a forward portion of the main frame.
High-strength material is poured into the area corresponding to
Material with excellent weldability at the part corresponding to the rear part of the frame
It is characterized by being cast integrally by pouring
Sign.

[0010] The body frame of the motorcycle of the present invention
In some cases, the cross pipe is welded and therefore good weldability
The required rear part of the main frame is made of a material with excellent weldability.
Formed, while not reinforced by cross pipes,
Reaction force from the front wheels through the
The front part of the main frame, which requires great strength
It is made of a large material, and the main frame is integrally cast.
The quality of the material is effectively used and the quality is improved.
Up. Although these materials have different compositions, it is needless to say that they are the same kind of material, so that there is no problem in obtaining a member composed of a continuous integral casting.

[0011] When casting the main frame , a conventional casting facility is used, except that independent runners are formed in the mold in accordance with parts having different required functions, and the runners are poured into the respective runners. There is no need to make any changes to the casting or casting process and therefore no new capital investment.

[0012]

EXAMPLES Hereinafter, a description will be given Kazumi施例the body frame members of a motorcycle according to the onset bright.

FIG. 1 is a schematic side view of a motorcycle 1 provided with a body frame member according to the present invention, wherein FW is a front wheel, RW is a rear wheel, E is an engine, and F is a body frame.

The body frame F includes a front body frame 2 and a rear body frame 3. As shown in FIG. 2, the front body frame 2 is connected to a head pipe 4, a pair of left and right main frame pipes 5 connected to the head pipe 4 and extending rearward of the vehicle body, and connected to the main frame pipe 5 near the head pipe 4. Right and left main frame pipes 5 at the rear
And cross pipes 7, 8 and 9 connecting them. The rear body frame 3 has a front end screwed and fixed to the front body frame 2 and extends rearward.
Is mounted, and a fuel tank T is disposed at the front. Electrical components EA such as an air cleaner AC and a battery are disposed in front of the fuel tank T.

The engine E is supported by the front body frame 2 at the lower ends of the left and right engine support pipes 6, the upper rear portions of the left and right main frame pipes 5 and the lower rear ends of the left and right main frame pipes 5. A rear fork 11 is pivotally supported via a support shaft 10 at a lower rear portion of the left and right main frame pipes 5, and a footrest member 12 is attached thereto.

The front body frame 2 includes a half of the head pipe 4 and one of the left and right main frame pipes 5.
The left and right front body frame halves 13L, 13R, which are integrated with the engine support pipe 6, are welded to each other at the front end, and the cross pipe 7,
They are assembled by connecting them by 8,9. Both ends of the cross pipes 7, 8, 9 are fitted and welded to the openings or holes of the halves 13L, 13R.

The front body frame halves 13L, 13R
Is an integral casting made of a light alloy material, which is cast by the method of the present invention as described later.

FIG. 3 is a side view of the left front body frame half 13L viewed from the outside. The main portion of the half body 13L has a tubular shape with a rectangular cross section as shown in FIGS.

In FIG. 3, 14a, 14b and 14c are half bodies 13L.
The ends of the cross pipes 7, 8, and 9 are fitted to these openings and welded to the openings. In the rear part of the half body 13L provided with the openings 14a, 14b, 14c, a hole 15 for supporting the support shaft 10 of the rear fork 11, a bracket 16a for supporting the engine E,
16b, bracket for connecting the rear body frame 3
Brackets 18 for attaching the footrest members 12 and 17a, 17b are integrally formed. Therefore, the rear portion is desirably formed of a material having good weldability and good moldability during casting.

On the other hand, the front portion of the half body 13L has few portions requiring welding as described above, and has a simple shape as compared with the rear portion. Weldability and formability are not required. However, this front part is at the front end via the head pipe 4
The strength is especially important for this part because it receives the reaction force from FW. Therefore, it is desirable that the front portion is formed of a material having high strength.

Therefore, the left and right front vehicle body frame halves 13 in the present embodiment are integrally cast with the same type of light alloy material, and the material composition is changed between the rear part and the front part. That is, the rear portion is formed of a material having a composition excellent in formability and weldability, for example, an AC4C-based material, and the front portion is formed of a material having a composition excellent in strength, for example, a 6300-based material. Such a front body frame half 13
Is obtained by casting as follows.

FIGS. 6 and 7 show a mold for casting the front body frame half 13. As shown in FIG. 7, this mold includes a mold 19a forming the outer surface side in the vehicle width direction of the front body frame half 13 and a mold 19 forming the inner surface side.
b, and a core 21 is set in a cavity 20 formed therein by the molds 19a and 19b. The core 21 is supported by the mold 19a, and the supporting portion 21a
Thus, the opening 14a is formed. FIG. 6 is an elevation view showing the mating surface 22 of the mold 19b.

The mating surface 22 is provided with a cavity 20 having the same shape as the front body frame half 13 to be cast. As can be seen by comparing FIGS. 6 and 3, in the cavity 20 of FIG. 6, the left region I corresponds to the rear portion of the front body frame half 13, and the right region II corresponds to the front portion. I do. Therefore, hereinafter, the region I side is referred to as the rear of the cavity 20, and the region II side is referred to as the front of the cavity 20.

The mold 19b has two independent runners.
23a and 23b and runners 24a and 24b are provided, and these runners 23a and 23b and runners 24a and 24b
Or via the pool 26, another gate 27 and another gate
Communicates with 28. The runner 23a communicates with the cavity 20 at a pouring hole 29a provided at the rearmost portion of the region I, and the runner 23b communicates with the cavity 20 through the pouring hole 29b slightly forward and below. Runner 23b has cavity
The lower part 20 further extends forward, and communicates with the cavity 20 via a pouring hole 29c at a front part (region III) of the region I. On the other hand, the runner 24a has a region II in the pouring hole 29d.
The runner 24b communicates with the forefront part, and the pouring hole 29e communicates with the rear part (area IV) of the area II. Reference numeral 30 denotes a deaeration passage appropriately provided along the upper side of the cavity 20.

Materials A and B having different compositions are poured into the mold through a gate 27 and a gate 28, respectively. The gate 27 is connected to the cavity 20 through the runners 23a and 23b.
As a result of the above pouring, the region I of the cavity 20 is filled only with the material A since the gate 28 communicates with the regions II and IV of the cavity 20 through the runners 24a and 24b. , Region II is filled with material B only. Therefore, material A
By selecting a material having a composition excellent in formability and weldability (for example, AC4C system) and a material B having a composition having excellent strength (for example, 6300 system), the front body frame half The rear and front portions of the thirteen can each be formed of a material having a composition adapted to the function required of these portions.

From the region III to the region IV, the two materials A and B have a mixed composition. In order to adjust the difference in the solidification rate depending on the physical properties of each material and to perform the mixing smoothly, the mixing is performed in this region. Is provided with a temperature control device 31 around the cavity 20.

In this way, as shown in FIG. 2, the rear part I is formed of a material having a good formability and weldability, and the front part II is formed of an integrally cast product formed of a material having a high strength. Front body frame halves 13L and 13R are obtained. The portions V of the front body frame halves 13L and 13R, which are surrounded by two-dot chain lines in FIG. 2, are welded to each other and are relatively complicated in shape. May be formed of the same material. For this purpose, the runner 24a of FIG.
A runner communicating with the forefront portion of II and a sprue leading to the runner may be provided, and the material A may be poured from the spout.

[0028]

According to the present invention, the head pipe is positioned rearward.
A pair of main frames extending left and right, and the pair of main frames
Cross pipe welded to the rear part of the
In the motorcycle body frame consisting of
Each part of the main frame made of the product that has different required functions
Each is formed of a material having a composition according to its function
Therefore, the properties of the material are effectively used and have high quality
Body frame is obtained. And cast the main frame
To make significant changes to the existing casting equipment and processes.
No capital investment is required.

[0029]

[0030]

[Brief description of the drawings]

FIG. 1 is a schematic side view of a motorcycle including a vehicle body frame member according to the present invention.

FIG. 2 is a plan view of a front body frame.

FIG. 3 is a side view showing a left half of the front body frame.

FIG. 4 is a sectional view taken along line IV-IV in FIG. 3;

FIG. 5 is a sectional view taken along the line VV of FIG. 3;

FIG. 6 is an elevation view showing a mating surface of one mold.

FIG. 7 is a partial cross-sectional view of the mold taken along line VII-VII of FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Motorcycle, 2 ... Front body frame, 3 ... Rear body frame, 4 ... Head pipe, 5 ... Main frame pipe,
6 ... engine support pipe, 7, 8, 9 ... cross pipe,
10 ... support shaft, 11 ... rear fork, 12 ... footrest member, 13 ... front body frame half, 14 ... opening, 15 ... hole, 16, 17, 18 ...
Bracket, 19 mold, 20 cavity, 21 core, 22
... mating surfaces, 23, 24 ... runners, 25, 26 ... pools, 27, 28 ...
Gate, 29: pouring hole, 30: deaeration passage, 31: temperature control device.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-5-69082 (JP, A) JP-A-3-189065 (JP, A) JP-A-5-78773 (JP, A) JP-A-1- 215437 (JP, A) JP-A 2-124784 (JP, U) JP-A 1-172992 (JP, U) JP-A 63-98889 (JP, U) (58) Fields surveyed (Int. Cl. ⁷ , DB name) B22D 19/16 B22D 19/00 B62K 19/12

Claims (1)

(57) [Claims] 1. The right and left sides extending rearward from a head pipe.
A pair of main frames and a rear portion of the pair of main frames are melted.
An automatic motor consisting of
In the vehicle body frame of a wheeled vehicle, the main frame is formed by casting.
In the mold corresponding to the front part of the main frame.
Pours a strong material into the back of the main frame
Pouring a material with excellent weldability into the area corresponding to
Motorcycle characterized by being integrally cast by
Car body frame.