JP2003033822A - Bulge processing method for hollow strength members for motorcycles - Google Patents

Abstract

(57) [Summary] (with correction) [PROBLEMS] To easily obtain a hollow strength member whose circumferential thickness changes according to required strength and rigidity by bulging. SOLUTION: A thickness-variable pipe material 1 whose thickness change portion of a peripheral wall substantially corresponds to a thickness change portion of a peripheral wall required for a product is provided. A hollow strength member (2) is provided in which a liquid is press-fitted and an intermediate portion thereof swells into a predetermined shape.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bulging method for forming a hollow strength member for a motorcycle, for example, an arm main body of a rear arm by bulging.

[0002]

2. Description of the Related Art Conventionally, when bulging an arm main body of a rear arm, a pipe material made of an aluminum alloy having a uniform peripheral wall thickness is compressed in the axial direction while a liquid is press-fitted into the middle of the pipe material. The part was made to swell to a predetermined shape.

[0003]

In the above-mentioned conventional one, the wall thickness of the molded peripheral wall is substantially the same over the entire circumference. For this reason, conventionally, it was not possible to reduce the weight and save the material by thinning a part of the wall thickness in the circumferential direction that is excessive. As a countermeasure for this, there is a means to change the wall thickness of the peripheral wall by swaging or spinning the pipe material, but this is not suitable for products with complicated shapes as productivity becomes poor. . An object of the present invention is to obtain a method for bulging a hollow strength member for a motorcycle, which solves the above problems.

[0004]

The present invention is configured as follows to achieve the above object. That is, the invention according to claim 1 provides an uneven wall thickness pipe material in which the wall thickness change portion of the peripheral wall substantially corresponds to the wall thickness change portion of the peripheral wall required for the product, and compresses the uneven wall thickness pipe material in the axial direction. At the same time, a hollow strength member is provided in which a liquid is press-fitted and the intermediate portion thereof swells into a predetermined shape. According to a second aspect of the present invention, the hollow strength member has a cross-sectional shape in which the bulge amount of the intermediate portion in the longitudinal direction is larger than both ends in the longitudinal direction and the left and right walls are longer than the upper and lower walls. In the invention according to claim 3, in the uneven thickness pipe material and the hollow strength member, the left and right peripheral walls are made thinner than the upper and lower walls. According to a fourth aspect of the present invention, the uneven thickness pipe material and the hollow strength member are configured such that the left and right walls of the peripheral wall are thinner than the upper and lower walls, and the raised portions that are thicker than the left and right walls in the vertical center portion of the left and right walls. Is provided. According to a fifth aspect of the present invention, in the uneven thickness pipe material and the hollow strength member, the left and right walls of the peripheral wall are made thinner than the upper and lower walls, and a groove portion thinner than the thickness of the left and right walls is formed in the vertical center of the left and right walls. It is provided.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. 1 to 5 show a bulging method according to a first embodiment of the present invention, FIG. 1 is a partial sectional side view of an uneven thickness pipe material, FIG. 2 is an enlarged sectional view taken along line II-II of FIG. 3 is a partial sectional side view of the bulge-processed rear arm main body portion, FIG. 4 is an enlarged sectional view taken along the line IV-IV of FIG. 3, and FIG.
-V enlarged sectional view, FIG. 6 is a plan view of the rear arm, and FIGS. 7 to 9 show a bulging method according to a second embodiment of the present invention.
7 is a partial cross-sectional side view of the bulge-processed main body of the rear arm, FIG. 8 is an enlarged cross-sectional view taken along line VIII-VIII of FIG. 7, and FIG. 9 is I of FIG.
X-IX enlarged sectional view, FIGS. 10 to 14 show a bulging method according to a third embodiment of the present invention, FIG. 10 is a partial sectional side view of an uneven thickness pipe material, and FIG. 11 is XI-XI of FIG. Enlarged sectional view, FIG. 12 is a partial sectional side view of a bulge-processed rear arm main body portion, FIG. 13 is an enlarged sectional view of XIII-XIII of FIG. 12, FIG. 14 is an enlarged sectional view of XIV-XIV of FIG. 12, and FIGS. 19 shows a bulge forming method according to a fourth embodiment of the present invention, and FIG.
5 is a partial cross-sectional side view of the uneven thickness pipe material, and FIG.
XVI-XVI enlarged sectional view, FIG. 17 is a partial sectional side view of the bulge-processed rear arm main body part, and FIG. 18 is XVIII-XV of FIG.
III is an enlarged sectional view, and FIG. 19 is an enlarged sectional view taken along line XIX-XIX in FIG.

1 to 5 show a method of bulging a hollow strength member according to a first embodiment of the present invention. First, FIG. 1 and FIG.
As shown in FIG. 3, the uneven thickness pipe material 1 made of aluminum alloy is formed by drawing or extruding so that the left and right walls 1a, 1a of the peripheral wall are thinner than the upper and lower walls 1b, 1b. The positions of the thin-walled portions (left and right walls 1a, 1a) and the thick-walled portions (upper and lower walls 1b, 1b) of the uneven wall thickness pipe material 1, that is, the wall thickness changing portion corresponds to the wall thickness changing portion of the peripheral wall required for the product. Let Further, the amounts of the thin wall portion and the thick wall portion of the uneven wall thickness pipe material 1 are appropriately set according to the strength, rigidity, etc. required of the product.

Then, as shown in FIG. 3, the uneven thickness pipe material 1 is bulged into a predetermined shape by a bulge processing machine 15-1. That is, the uneven thickness pipe material 1 is laid sideways, and the small diameter portions 16a and 17a of the metal step punches 16 and 17 are fitted to the left and right ends thereof to close both ends of the uneven thickness pipe material 1. In addition, the outer periphery of the uneven thickness pipe material 1 is provided with the upper and lower molds 18.
Surrounded by -1, 19-1.

Then, while the uneven thickness pipe material 1 is axially compressed by the punches 16 and 17, molding oil is pressurized and supplied from the oil passages 16b and 17b penetrating the axial center of the uneven thickness pipe material 1 to obtain the uneven thickness pipe material. 1. A hollow strength member having a shape in which the intermediate portion of 1 is along the molding surface of the upper and lower molds 18-1 and 19-1, that is, as shown in FIG. Further, as shown in FIGS. 4 and 5, the arm main body portion 2 of the rear arm is formed in which the left and right walls 2a, 2a of the peripheral walls have an elliptical shape whose cross section is long in the up and down direction and whose thickness is smaller than that of the upper and lower walls 2b, 2b. .

As shown in FIG. 6, the arm main body 2 is disposed so as to face left and right (upper and lower in FIG. 6), is welded and fixed to the left and right sides of the head bracket 4 on the front side, and the rear wheel is attached to the rear end. Brackets 5 and 5 are mounting brackets 6 and 6 on the opposite side.
Etc. are welded and fixed to form a fork-shaped rear arm 3.

7 to 9 show a method of bulging a hollow strength member according to a second embodiment of the present invention. That is, as shown in FIG. 7, the eccentricity pipe material 1 similar to that described above is used as shown in FIG.
5-2-1 is bulging-molded into a predetermined shape. That is, the uneven thickness pipe material 1 is turned sideways, and the left and right ends thereof are fitted with the small diameter portions 16a and 17a of the punches 16 and 17 to close both ends of the uneven thickness pipe material 1 as described above. The outer periphery of the uneven thickness pipe material 1 is surrounded by the upper and lower molds 18-2 and 19-2.

In this state, the punches 16 and 17 compress the non-uniform wall thickness pipe material 1 in the axial direction, and the molding oil is pressurized and supplied from the oil passages 16b and 17b penetrating the axial center of the pipe material 1.
The upper and lower dies 18-2, 19-
2, a hollow strength member having a shape along the molding surface, that is, as shown in FIG. 7, in a gentle mountain shape in a side view in which the central portion in the longitudinal direction gradually becomes wider, and as shown in FIGS. 8 and 9. , A rectangular shape whose cross section is long in the vertical direction and the left and right walls 7a, 7 of the peripheral wall
The arm main body portion 7 of the rear arm is formed in which a is thinner than the upper and lower walls 7b and 7b.

10 to 14 show a method of bulging a hollow strength member according to a third embodiment of the present invention. First, Fig. 1
0, as shown in FIG. 11, the left and right walls 8a, 8a of the peripheral wall are changed to upper and lower walls 8b, 8b by drawing or extruding.
A thin ridge portion 8c, which is thinner than the left and right walls 8a, 8a and is thicker than the wall thickness of the left and right walls 8a, 8a.
The uneven thickness pipe material 8 having 8c is formed. This ridge 8
c and 8c are formed to extend over the entire length of the uneven thickness pipe material 8.

Next, as shown in FIG. 12, the uneven wall thickness pipe material 8 is bulged into a predetermined shape by a bulge processing machine 15-3. That is, the uneven thickness pipe material 8 is turned sideways, and the left and right ends thereof are fitted with the small-diameter portions 16a and 17a of the punches 16 and 17 similar to those described above to close both ends of the uneven thickness pipe material 8. , The upper and lower molds 18-
Surrounded by 3, 19-3.

Next, while the uneven thickness pipe material 8 is compressed in the axial direction by the punches 16 and 17, the molding oil is pressurized and supplied from the oil passages 16b and 17b formed in the axial center portion thereof, and the uneven thickness pipe material 8 is formed. 12, a hollow strength member having a shape along the molding surface of the upper and lower molds 18-3, 19-3, that is, as shown in FIG. In addition, as shown in FIGS. 13 and 14, the cross section is formed in a rectangular shape that is long in the vertical direction, and the left and right walls 9a, 9a of the peripheral wall are thinner than the upper and lower walls 9b, 9b, and the left and right walls 9a, 9a. The left and right walls 9a in the vertical center of the
The arm main body portion 9 of the rear arm having the narrowed ridges 9c, 9c thicker than the wall thickness of 9a is formed.

15 to 19 show a method of bulging a hollow strength member according to a fourth embodiment of the present invention. First, Fig. 1
As shown in FIG. 5 and FIG. 16, the left and right walls 10a, 10a of the peripheral wall are made the upper and lower walls 10 by drawing or extruding.
An uneven wall thickness pipe material 10 is formed which is thinner than the left and right walls 10a and 10a and has narrow groove portions 10c and 10c thicker than the left and right walls 10a and 10a at the center of the left and right walls 10a and 10a in the vertical direction. The groove portions 10c, 10c are provided with the uneven thickness pipe material 10
Is formed over the entire length of.

Next, as shown in FIG. 17, the uneven thickness pipe material 10 is bulged into a predetermined shape by a bulge processing machine 15-4. That is, the uneven thickness pipe material 10 is laid sideways, and the left and right ends thereof are fitted with the small-diameter portions 16a and 17a of the punches 16 and 17 which are substantially similar to those described above to close both ends of the uneven thickness pipe material 10. The outer circumference of the uneven thickness pipe material 10 is surrounded by the upper and lower molds 18-4 and 19-4.

Next, while compressing the uneven thickness pipe material 10 in the axial direction by the punches 16 and 17, the molding oil is pressurized and supplied from the oil passages 16b and 17b formed in the axial center portion of the uneven thickness pipe material 10 to thereby compress the uneven thickness pipe material 10. The upper and lower molds 18-4, 19-
4, a hollow strength member having a shape along the molding surface, that is, as shown in FIG. 17, in a gentle mountain shape in side view in which the central portion in the longitudinal direction gradually becomes wide, and as shown in FIGS. 18 and 19. The cross section is formed in a rectangular shape that is long in the vertical direction, and the left and right walls 11a, 11a of the peripheral walls are the upper and lower walls 11b, 11
The arm main body 1 of the rear arm, which is thinner than b and has narrow groove portions 11c, 11c thicker than the wall thickness of the left and right walls 11a, 11a in the vertical center of the left and right walls 11a, 11a.
1 is formed.

[0018]

As is apparent from the above description, according to the present invention, an uneven wall thickness pipe material is provided in which the wall thickness change portion of the peripheral wall substantially corresponds to the wall thickness change portion of the peripheral wall required for the product. While compressing the material in the axial direction, a hollow strength member that presses liquid into the inside and bulges into a predetermined shape in the middle part is provided, so the required strength and rigidity are achieved by bulging with high productivity. It is possible to easily obtain a hollow strength member whose wall thickness changes in the circumferential direction according to the above.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional side view of an uneven wall thickness pipe material according to a first embodiment of the present invention.

2 is an enlarged sectional view taken along line II-II of FIG.

FIG. 3 is a partial cross-sectional side view of the rear arm main body according to the first embodiment of the present invention.

FIG. 4 is an enlarged sectional view taken along the line IV-IV of FIG.

5 is an enlarged sectional view taken along line VV of FIG.

FIG. 6 is a plan view of a rear arm formed according to the present invention.

FIG. 7 is a partial sectional side view of a rear arm main body portion according to a second embodiment of the present invention.

FIG. 8 is an enlarged sectional view taken along the line VIII-VIII of FIG.

9 is an enlarged sectional view taken along line IX-IX of FIG.

FIG. 10 is a partial cross-sectional side view of an uneven wall thickness pipe material according to a third embodiment of the present invention.

11 is an enlarged cross-sectional view taken along line XI-XI of FIG.

FIG. 12 is a partial cross-sectional side view of a rear arm main body portion according to a third embodiment of the present invention.

13 is an enlarged sectional view taken along line XIII-XIII in FIG.

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

FIG. 15 is a partial cross-sectional side view of an uneven wall thickness pipe material according to a fourth embodiment of the present invention.

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

FIG. 17 is a partial cross-sectional side view of a rear arm main body portion according to the fourth embodiment of the present invention.

18 is an enlarged sectional view taken along line XVIII-XVIII in FIG.

19 is an enlarged sectional view taken along line XIX-XIX in FIG.

[Explanation of symbols]

1 (8, 10) Unequal wall thickness pipe material 1a (8a, 10a) Left and right walls 1b (8b, 10b) of peripheral wall Upper and lower walls 2 (7, 9, 11) of peripheral wall Rear arm main body (hollow strength member) 2a (7a, 9a, 11a) Left and right walls 2b (7b, 9b, 11b) of the peripheral wall Upper and lower walls 8c (9c) of the peripheral wall Raised part 10c (11c) Groove part 15-1 (15-2, 15-3, 15-4) Bulge processing machine 16,17 Punches 16a, 17a Small diameter parts 16b, 17b Oil passage 18-1 (18-2, 18-3, 18-4) Upper mold 19-1 (19-2, 19-3, 19-4) Lower mold

Continued front page    (72) Inventor Yuji Mizuno             10 stock associations at 1417 Kinoricho, Hamamatsu City, Shizuoka Prefecture             Shakyoei Factory F-term (reference) 3D012 BC01 BC03

Claims (5)

[Claims] 1. An uneven wall thickness pipe material (1, 8,) in which the wall thickness changing portion of the peripheral wall substantially corresponds to the wall thickness changing portion required for the product.
10) is provided, and the uneven thickness pipe material (1, 8, 10) is compressed in the axial direction, and a liquid is press-fit into the hollow strength member (2, 7, 9. A bulging method for a hollow strength member for a motorcycle, characterized in that: 2. The hollow strength member (2) has a larger amount of bulge in the middle portion in the longitudinal direction than both ends in the longitudinal direction, and the left and right walls (2).
The method for bulging a hollow strength member for a motorcycle according to claim 1, wherein a) has a cross-sectional shape that is longer than the upper and lower walls (2b). 3. An uneven wall thickness pipe material (1) and a hollow strength member (2) are provided with upper and lower walls (1b, 1a, 2a) of the peripheral wall.
The thickness is smaller than that of 2b).
A method for bulging a hollow strength member for a motorcycle as described above. 4. The uneven thickness pipe material (8) and the hollow strength member (9) are formed by connecting the left and right peripheral walls (8a, 9a) to upper and lower walls (8b, 8b).
9b) and is made thinner than the left and right walls (8a, 9).
The motorcycle (1) according to any one of claims 1 to 3, wherein a raised portion (8c, 9c) thicker than the wall thickness of the left and right walls (8a, 9a) is provided at the center of the vertical direction of (a). Bulge processing method for hollow strength members. 5. The uneven thickness pipe material (10) and the hollow strength member (11) have the left and right walls (10a, 11a) of the peripheral wall thinner than the upper and lower walls (10b, 11b), and the left and right walls (10a, 11a). ) In the vertical center of the left and right walls (1
Grooves (10c, 11c) thinner than 0a, 11a)
The method for bulging a hollow strength member for a motorcycle according to any one of claims 1 to 4, further comprising: