JP2000351056A - Production of vehicle body part and vehicle body part - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method capable of suppressing cost increase of a vehicle body part and providing the vehicle body part with a light weight and a constitution having a sound silencing effect. SOLUTION: When casting a hollow body 21 of a swing arm 20, bubbled metal pieces 26-29 of light weight members are integrally cast-in. Thus, a light weight swing arm 20 is simply produced without increasing a production process. Further, the bubbled metal pieces 26-29 are integrally incorporated to a hollow part of the hollow body 21 as a reinforcing material, resonance of the swing arm 20 is suppressed as well as toughness of the swing arm is increased.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a vehicle body component in which a reinforcing member is integrally attached to a hollow vehicle body component, and a vehicle body component.

[0002]

2. Description of the Related Art FIG. 10 is a plan view of a conventional swing arm for a motorcycle. The swing arm 100 has a left and right main pipes 102,
103, the left and right front ends 101a of the hollow body 101,
101a is rotatably attached to a body frame 106 by a pivot shaft 105, and left and right main pipes 102, 103
Left and right axle support members 108 and 109 are attached to the rear end, and an axle 112 for a rear wheel 110 is attached to these axle support members 108 and 109.

[0003] The swing arm 100 includes a hollow body 10.
Since the main pipe 1 and the left and right main pipes 102 and 103 have a hollow structure, resonance noise is likely to be generated when the main pipe 102 and 103 resonate due to vibration of an engine, a drive chain or the like. Further, since the swing arm 100 is attached to the vehicle body frame 106 only by the pivot shaft 105, it is required to be cantilevered and to increase the rigidity of the hollow body 101.

For this reason, the resonance of the swing arm 100 can be suppressed by adding ribs 115... As reinforcing materials to the hollow portion of the hollow body 101 or increasing the thickness of the left and right main pipes 102 and 103. The generation of resonance noise is prevented, and the rigidity of the swing arm 100 is increased. Hereinafter, the ribs 115 of the hollow body 101 will be described with reference to the following drawings.

FIG. 11 is a sectional view taken along line 11-11 of FIG. 10 and shows a state in which a rib 115 is formed on the inner peripheral surface 101b of the hollow body 101. By forming the rib 115 on the hollow body 101, the resonance of the swing arm 100 can be suppressed by changing the natural frequency of the swing arm 100, and the rigidity of the swing arm 100 can be further increased. However, when the ribs 115 are formed in the hollow body 101, the weight of the swing arm 100 increases and the vehicle weight increases.

Returning to FIG. 10, on the other hand, it is possible to suppress resonance and increase rigidity by increasing the thickness of the left and right main pipes 102, 103. However, when the thickness of the left and right main pipes 102 and 103 is increased,
The weight of the swing arm 100 increases and the vehicle weight increases.

For this reason, the left and right main pipes 102, 1
A technique for suppressing the resonance without increasing the thickness of No. 03 has been proposed in Japanese Utility Model Registration No. 2504280, entitled "Swing Arm of Motorcycle". In this technique, a vibration damping member is inserted into the left and right main pipes of a swing arm, thereby suppressing resonance of the main pipe with the vibration damping member and suppressing generation of resonance noise. Since it is not necessary to increase the thickness of the main pipe, it is possible to suppress an increase in vehicle weight.

[0008]

However, since the damping members inserted into the left and right main pipes are relatively long, it is difficult to smoothly insert the damping members into the main pipes. For this reason, it is conceivable that a plurality of workers are required to insert the vibration damping members into the left and right main pipes, and it takes time to insert the vibration damping members.
This will increase costs.

SUMMARY OF THE INVENTION An object of the present invention is to provide a technique capable of suppressing an increase in the cost of a vehicle body component and making the vehicle body component light in weight and having a noise-reducing effect.

[0010]

According to a first aspect of the present invention, a metal foam piece is placed at a predetermined position of a mold for casting a hollow body component, and then the molten metal is poured into the mold. Then, the pieces are integrated into a hollow body component to integrally cast the pieces like bamboo nodes.

When casting a vehicle body component, a foamed metal piece as a lightweight member is integrally cast. For this reason, a lightweight vehicle body component can be easily manufactured without increasing the number of manufacturing steps. Further, after manufacturing the vehicle body component, the labor for inserting the vibration damping member into the hollow portion of the vehicle body component can be saved.

A second aspect of the present invention relates to a vehicle body component in which a reinforcing piece is integrally inserted into a hollow portion of a casting like a bamboo node.
The reinforcing piece is a foamed metal piece.

A metal foam piece was integrally inserted as a reinforcing material into a hollow portion of a vehicle body component. Since the metal foam piece is a lightweight member, the weight of the vehicle body component can be reduced. Further, by incorporating the foamed metal piece integrally with the vehicle body component, resonance of the vehicle body component can be suppressed and the rigidity of the vehicle body component can be increased.

[0014]

Embodiments of the present invention will be described below with reference to the accompanying drawings. Note that "before", "after",
“Left”, “right”, “up”, and “down” follow directions viewed from the driver, and F indicates the front side, R indicates the rear side, L indicates the left side, and R indicates the right side. Also, the drawings should be viewed in the direction of reference numerals.

FIG. 1 is a side view of a motorcycle using a vehicle body component (first embodiment) according to the present invention. The motorcycle 10 includes a body frame 11 and a body frame 11.
Front fork 13 attached to the head pipe 12
A handle 14 attached to the upper end of the front fork 13; a front wheel 15 attached to the lower end of the front fork 13; a fuel tank 16 attached above the front of the body frame 11; and a seat attached to the rear of the fuel tank 16. 17, a power unit 18 (combination of an engine 18a and a transmission 18b) mounted below the front end of the body frame 11, and a swing as a vehicle body component supporting the rear wheel 19 by being cantilevered at the rear of the body frame 11. And an arm 20. Hereinafter, the swing arm 20 according to the present invention will be described.

FIG. 2 is a sectional view taken along line 2-2 of FIG. The swing arm 20 is composed of a left and right rear end 2 of a substantially U-shaped hollow body 21.
Openings 23a, 23b are respectively formed in 2a, 22b, and left and right main pipes 3 are formed in these left and right openings 23a, 23b.
0, 31 are attached to the left and right front ends 24 of the hollow body 21.
a, 24b are connected to the body frame 11 by the pivot shaft 33 (FIG. 1).
), And the left and right main pipes 3
Left and right axle support members 35 and 36 are attached to the rear ends of 0 and 31. In the swing arm 20, the rear wheel 19 is attached to the left and right axle support members 35 and 36 by an axle 41.

The hollow body 21 forms a hollow portion 26 with an inner peripheral surface 25, and the foamed metal pieces 27, 27, 2 are formed in the hollow portion 26.
It is a cast product in which 8, 28, and 29 are integrally inserted as a reinforcing material like bamboo nodes. Foam metal pieces 27, 27, 2
8, 28 and 29 are substantially the same members, so only the foamed metal piece 29 will be described below and the other pieces 27 and 2 will be described.
The description of 8 is omitted.

FIG. 3 is a sectional view taken along line 3-3 of FIG. The foam metal piece 29 is formed by processing a plate-like foam metal having a closed-cell thin film cell structure into a rectangular cylindrical body, and is a member in which the outer periphery 29 a is integrally cast on the inner peripheral surface 25 of the hollow body 21. . The foam metal is, for example, an aggregate of bubbles formed of a thin film of aluminum in which alumina is uniformly dispersed, and is formed into a polyhedron in order to three-dimensionally stabilize each bubble.

The foam metal has a specific gravity of 0.2 to 0.3.
This is a member that is ultra-light, approximately 1/10 of aluminum and approximately 1/30 of cast iron, and can withstand high temperatures of 780 ° C. Further, the foamed metal is a member that can be cut into a desired shape with a saw or the like and that can be formed into a cylindrical body by bending. Therefore, if the plate-shaped foamed metal is prepared, the plate-shaped foamed metal is formed into a desired shape (for example, foamed metal pieces 27, 27, 28, 28, 29).
Can be easily processed.

As described above, since the lightweight foamed metal piece 29 is integrally inserted into the hollow body 21 as a reinforcing material, the weight of the swing arm 20 can be reduced.
Further, by using the foamed metal piece 29 as a reinforcing material, the rigidity of the swing arm 20 can be increased, and the generation of resonance due to resonance can be prevented.

Next, a method of manufacturing the swing arm 20 will be described. FIGS. 4A and 4B are diagrams illustrating a first manufacturing process of the vehicle body component (first embodiment) according to the present invention. In (a), a substantially U-shaped core 52 is set on a molding surface 51a of a lower mold 51 of a mold 50 as a mold as indicated by an arrow, and cylindrical cores 53, 53 are indicated by arrows on the molding surface 51a. Set as shown. The core 52 is formed by integrally embedding pieces of metal foam 27, 27, 28, 28, 29. Next, the upper mold 55 is moved as indicated by an arrow to clamp the mold 50. In (b), the molten metal is supplied from the gate 56 as shown by the arrow, and the cavity 57 is filled with the molten metal.

FIGS. 5A to 5C are views for explaining a second manufacturing process of the vehicle body components (first embodiment) according to the present invention. In (a), after the molten metal 58 in the cavity 57 is solidified, the upper mold 55 is moved as shown by the arrow to move the mold 50.
Open the mold. In (b), the hollow body 21 is released from the mold. Next, the cores 52, 53, 53 are removed from the inside of the hollow body 21 by setting the hollow body 21 on a vibrator (not shown) and vibrating the hollow body 21. Since the extraction holes 21a are formed in the hollow body 21, the core 52 can be efficiently removed. In addition, the opening size and opening position of the extraction hole 21a can be arbitrarily selected. In (c), the front ends of the left and right main pipes 30 and 31 are inserted into the left and right openings of the hollow body 21 and welded to 23a and 23b.
Thereby, the manufacturing process of the swing arm 20 is completed.

As described above, when casting the hollow body 21, the foam metal pieces 27, 27, 28, 28, 29 can be integrally cast. Therefore, the lightweight swing arm 20 can be easily manufactured without increasing the number of manufacturing steps.

Next, second to seventh embodiments will be described. The same members as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted. FIG.
(A)-(c) is sectional drawing which shows the foamed metal piece (2nd-4th embodiment) of the vehicle body component part which concerns on this invention, (a) is 2nd Embodiment, (b) Shows a third embodiment, and (c) shows a fourth embodiment.

The foamed metal piece 60 shown in FIG.
(Embodiment) is the foamed metal piece 2 of the first embodiment.
9 is a member corresponding to the first piece 60.
a, the second piece 60b, the third piece 60c, and the fourth piece 60d are processed in a state of being divided into four, and the first to fourth pieces 6 are formed.
0a to 60d are combined to form a rectangular tube. By dividing the foamed metal piece 60 into four parts, it becomes easier to work from a plate-like foamed metal. As a result, productivity can be improved, and cost increase can be suppressed.

The foam metal piece 63 shown in FIG.
(Embodiment) is the foamed metal piece 2 of the first embodiment.
A member corresponding to No. 9 in which a foam metal is formed in a rectangular shape. By making the foam metal piece 63 rectangular, resonance can be suppressed more efficiently, and the rigidity can be further increased.

The foam metal piece 65 shown in FIG.
(Embodiment) is the foamed metal piece 2 of the first embodiment.
A member corresponding to No. 9 in which a foam metal is formed in a substantially cross shape. Even when the foamed metal piece 65 is used, the resonance can be suppressed and the rigidity can be increased as in the foamed metal piece of the above-described embodiment.

FIGS. 7 (a) and 7 (b) are side views of a vehicle body component (fifth embodiment) according to the present invention. The vehicle body component according to the present invention is shown in a vehicle body frame 11 (shown in FIG. 1). Here is an example applied to The body frame 11 is attached to the left and right main frames 70, 7 by the head pipe 12 as shown in FIG.
The left and right pivot support frames 73 and 74 are welded to the rear ends 70b and 71b of the left and right main frames 70 and 71, respectively. The left and right pivot support frames 73, 74 are provided with mounting holes 73a, 74 for mounting the swing arm 20 shown in FIG.
a (74a is not shown).

The left and right main frames 70, 71 are hollow bodies having a rectangular cross section, and have foam metal pieces 75, 75 attached to hollow portions 70c, 71c of front ends 70a, 71a of the main frames 70, 71. It is. The left and right pivot support frames 73, 74 have front ends formed into hollow bodies having a rectangular cross section, and have hollow portions 73b, 74b.
And metal foam pieces 78, 78 attached thereto.

8A and 8B are cross-sectional views of a foam metal piece of a vehicle body component (fifth embodiment) according to the present invention, FIG. 8A is a cross-sectional view taken along line 8a-8a, and FIG. b) is 8b-
It is an 8b line sectional view. In (a), the metal foam piece 75 is formed by processing a plate-like metal foam having a closed-cell thin-film cell structure into a rectangular cylindrical body, similarly to the metal foam piece 29 of the first embodiment. And are members attached to the hollow portions 71c of the left and right main frames 71.
In (b), the foamed metal piece 78 is formed by processing a plate-shaped foamed metal having a closed-cell thin-film cell structure into a rectangular cylindrical body, similarly to the foamed metal piece 29 of the first embodiment. And the hollow portion 74 of the pivot support frame 74
It is a member attached to a.

Therefore, like the swing arm 20, the lightweight body frame 11 can be easily manufactured without increasing the number of manufacturing steps. Further, since the lightweight foamed metal piece is integrally inserted into the body frame 11 as a reinforcing material, the weight of the body frame 11 can be reduced. In addition, the rigidity of the vehicle body frame 11 can be increased by using the foamed metal piece as the reinforcing material, and the generation of resonance due to resonance can be prevented.

FIG. 9 is a sectional view taken along the line 9-9 in FIG. 2, and shows an example in which the vehicle body component according to the present invention is applied to a wheel 80. The wheel 80 has bearings 81 on the axle 41.
A hub 82 rotatably mounted via
And a rim 85 attached to the tip of the forks 84.
A hollow cylindrical metal piece 8 is formed in the hollow portion 82a of the hub 82.
6 is attached. The wheel 80 is rotatably mounted on the left and right support members 37 and 38 of the swing arm 20 via the axle 41, and the tire 90 is mounted on the rim 85. In this state, the sprocket 87 is moved by the drive chain 88 (shown in FIG. 1). The rotation causes the rear wheel 19 to rotate. Reference numeral 89 denotes a brake disk.

The foamed metal piece 86 is formed by bending a plate-shaped foamed metal having a closed-cell thin-film cell structure used for the foamed metal piece 29 of the first embodiment into a cylindrical shape, and coaxially with the axle 41. Further, it is a member attached to the hollow portion 82a of the hub 82.

Therefore, like the swing arm 20, the lightweight wheel 80 can be easily manufactured without increasing the number of manufacturing steps. Also, a lightweight foam metal piece 86
Is integrated into the wheel 80 as a reinforcing material, so that the weight of the wheel 80 can be reduced. Further, by using the foam metal piece 86 as a reinforcing material, the rigidity of the wheel 80 can be increased, and the generation of resonance due to resonance can be prevented.

In the above embodiment, an example in which an aluminum foam metal is used as the foam metal piece has been described. However, a manganese alloy, a zinc alloy, a titanium alloy, an iron alloy, or a stainless steel foam metal may be used. May be used. Although the foam metal was made a member that can withstand high temperatures of 780 ° C,
Not limited to 780 ° C. That is, it is only necessary that the foam metal piece can be integrally cast into the hollow part of the vehicle body component. Also, an example using a mold as a mold has been described,
In addition, the same effect can be obtained by using a sand mold.

Further, the example in which the foam metal piece is integrally cast with the vehicle body component has been described. For example, the foam metal piece may be press-fitted into the hollow portion of the vehicle body component. Further, although the body frame 11, the swing arm 20, and the wheel 80 have been described as examples of the body components, the body components may be applied to other members.

[0037]

According to the present invention, the following effects are exhibited by the above configuration. According to a first aspect of the present invention, a foamed metal piece as a lightweight member is integrally cast with a vehicle body component. For this reason, a lightweight vehicle body component can be easily manufactured without increasing the number of manufacturing steps. Further, after manufacturing the vehicle body component, the labor for inserting the vibration damping member into the hollow portion of the vehicle body component can be saved. As a result, an increase in the cost of the vehicle body component can be suppressed.

According to a second aspect of the present invention, a foam metal piece is integrally provided as a reinforcing material in a hollow portion of a vehicle body component. Since the metal foam piece is a lightweight member, the weight of the vehicle body component can be reduced. Further, by incorporating the foamed metal piece integrally with the vehicle body component, resonance of the vehicle body component can be suppressed and the rigidity of the vehicle body component can be increased. By suppressing the resonance, it is possible to make the vehicle body components lightweight and have a sound-absorbing effect.

[Brief description of the drawings]

FIG. 1 shows a vehicle body component according to the present invention (first embodiment).
Side view of motorcycle using

FIG. 2 is a sectional view taken along line 2-2 of FIG.

FIG. 3 is a sectional view taken along line 3-3 in FIG. 2;

FIG. 4 is a vehicle body component according to the present invention (first embodiment).
1st manufacturing process explanatory drawing

FIG. 5 is a vehicle body component according to the present invention (first embodiment).
2nd manufacturing process explanatory drawing

FIG. 6 is a sectional view showing a foam metal piece (second to fourth embodiments) of a vehicle body component according to the present invention.

FIG. 7 shows a vehicle body component according to the present invention (fifth embodiment).
Side view of

FIG. 8 shows a vehicle body component according to the present invention (fifth embodiment).
Sectional view of a foam metal piece

FIG. 9 is a sectional view taken along line 9-9 in FIG. 2;

FIG. 10 is a plan view of a conventional swing arm for a motorcycle.

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

[Explanation of symbols]

11: body component (body frame), 20: body component (swing arm), 21: hollow body, 26: hollow part, 27, 28, 29, 60, 63, 65, 75, 7
8, 86: foam metal piece, 50: mold (die), 8
0: Body components (wheels).

Claims (2)

[Claims] 1. A foamed metal piece is placed at a predetermined position of a mold for casting a hollow body component, and then poured into the mold to integrate the piece into a hollow body component. A method for manufacturing a vehicle body component, wherein a piece is integrally cast as in a knot. 2. A vehicle body component in which a reinforcing piece is integrally inserted into a hollow portion of a casting like a bamboo node, wherein the reinforcing piece is a foam metal piece.