JPH0788583A - Production of two-piece aluminum wheel - Google Patents

Abstract

PURPOSE:To reduce the weight of a rim part by drawing a rim flange press- formed product when the rim part of a two-piece aluminum wheel is produced. CONSTITUTION:An intermediate product of rim is formed by forming a cylindrical aluminum rim material so the diameter of one end is expanded and the diameter of another end is reduced. One rim flange 3 is formed at the expanded side end by drawing the expanded side of intermediate product by press-forming and the root R part 6 of rim flange 3 is locally thickened. The locally thickened rim intermediate product is shaped in a specific shape by using a segmental die and a lower stress generating position 8 of the rim is extended and thinned by spinning to be a finished rim part 1. The rim 1 is joined to a disk 2 having another flange 4 by welding 5. Thus, the wheel is made light in weight and economical in material consumption.

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 two-piece aluminum wheel in which two pieces of a rim and a disk are welded and joined.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 14, a rim 1 having only one rim flange 3 is welded to a disk 2 having another rim flange 4 by welding at the back surface of the disk.
Known two-piece aluminum wheels. This type of aluminum wheel has a good appearance because the joint between the rim and the disc cannot be seen from the front side of the disc, and has been widely used in recent years. The rims of the above types of aluminum wheels are
Usually, the wall of a straight cylindrical material is sandwiched between male and female rolls having a rim shape to form the rim shape.

[0003]

However, at the time of roll forming, the root R portion 6 of the rim flange is reduced by 10 to 18% from the wall thickness before roll forming. Since the root of the rim flange is also a site where high stress is generated, the rim material is made thick over the entire length to withstand that stress. However, this thick wall is excessively thick for the portion 8 having a low generated stress, which is located inward of the hump portion 7 in the axial direction, and causes problems of wasting material and increasing weight.
An object of the present invention is to provide a method for manufacturing a two-piece aluminum wheel that can reduce unnecessary thickness and reduce weight.

[0004]

A method for manufacturing a two-piece aluminum wheel of the present invention which achieves the above object is any one of the following methods (1), (2) and (3). ) Consists of. (1) An aluminum cylindrical rim material whose outer diameter is slightly smaller than the nominal diameter of the finished rim product is formed by butt-welding a flat plate into a cylindrical shape by butt-welding or extruding the cylindrical material. One end of the cylindrical rim material is expanded by press molding and the other end is reduced in diameter to form a rim intermediate product, and the expanded end of the rim intermediate product is drawn and expanded by a press. One rim flange is formed at the end on the radial side, the root R portion of the rim flange is locally thickened, and the locally thickened rim intermediate product is shaped into a predetermined shape using a split mold. , The portion of the rim hump that is lower in stress in the axial direction than the hump is extended by spinning to a specified rim length and the thickness of the spinning portion is reduced to form a finished rim, and the other rim flange is integrated. Disc back The finished product rim is welded to the side, the manufacturing method of the two-piece aluminum wheel. (2) A flat plate extruded material having a pre-groove at a portion corresponding to a portion having a low generated stress on the inner side of the hump portion in the axial direction when the rim is finished is rolled into a cylindrical shape in the groove extending direction, and the end portion is formed. Butt welding to form a cylindrical rim material of aluminum,
One end of the cylindrical rim material is expanded by press molding and the other end is contracted to form a rim intermediate product, and the end on the expanded side of the rim intermediate product is drawn by pressing. One rim flange is formed at the end on the diameter expansion side and the root R part of the rim flange is locally thickened, and the locally thickened rim intermediate product is shaped into a predetermined shape using a split mold. The finished product does not have a finished rim, and the part of the rim hump that has a lower stress generated in the axial direction is extended by spinning to a specified rim length, and the part that has been spun is reduced in thickness to give a finished rim. A method for manufacturing a two-piece aluminum wheel, wherein the finished product rim is welded and bonded to the back side of a disk integrally having the other rim flange. (3) An aluminum cylindrical rim material whose outer diameter is slightly smaller than the nominal diameter of the finished rim product is formed by butt welding the flat plate in a cylindrical shape by butt welding or extruding the cylindrical material. Of the cylindrical rim material, when a finished rim product is used, a portion corresponding to a portion having a low generated stress that is located on the inner side in the axial direction of the rim hump portion is subjected to spinning processing to locally reduce the thickness to the outer periphery. A cylindrical rim material having a groove is formed, one end of the cylindrical rim material is expanded by press molding and the other end is reduced in diameter to form a rim intermediate product. The end portion is drawn by a press to form one rim flange at the end portion on the diameter-expanding side, the root R portion of the rim flange is locally thickened, and the locally thickened rim intermediate product Using a split mold, shape the Spinning portion of the thickness decreasing to rim finished products and without with the lower part of stress generated in the axial direction inside the hump portion stretched by spinning a predetermined rim length, manufacturing method of two-piece aluminum wheel. (4) An aluminum cylindrical rim material having an outer peripheral diameter slightly smaller than the nominal diameter of the finished rim product is formed by butt-welding a flat plate into a cylindrical shape by butt-welding or extruding the cylindrical material. One end of the cylindrical rim material is expanded by press forming and the other end is reduced in diameter to form a rim intermediate product, and the end on the expanded side of the rim intermediate product is drawn and expanded by a press. One rim flange is formed at the end on the radial side, the root R part of the rim flange is locally thickened, and the locally thickened rim intermediate product is shaped into a predetermined shape using a split mold. And a finished product rim, and the finished product rim is welded and joined to the back side of a disc integrally having the other rim flange.

[0005]

In the above methods (1), (2), (3), and (4), the rim flange at one end of the rim is formed by pressing, so unlike the roll processing, the root R part of the rim flange is locally formed. It is possible to increase the thickness of the rim, and it is possible to locally increase the thickness of only the necessary portion where the generated stress is high without increasing the thickness of the rim over the entire length. In addition, as for the part where the generated stress is low, spin processing is performed after Mflange pressing as in (1), or a flat plate with a groove is rolled at the stage of flat plate material as in (2), or as in (3). Then, the thickness is locally reduced by either spinning the cylindrical material before the rim flange pressing or by spinning. However, the thickness reducing step may be removed as in (4). Due to the above, the high stress generation part is thickened, and the low stress generation part is thinned as necessary, the weight of the wheel rim as a whole can be reduced without lowering the required strength, and the aluminum material You can save.

[0006]

The preferred embodiments of the present invention will be described below.
As a matter of fact, items common to all the examples will be described. FIG. 1 shows the structure of a rim of a two-piece aluminum wheel and its vicinity after being manufactured by the method of the present invention. The disc wheel is formed by welding the rim 1 and the disc. The rim 1 has one rim flange 3 at one end, and is joined to the back surface of a disk 2 integrally having the other rim flange 4 by a weld portion 5. The root R portion 6 of the rim flange 3 of the rim 1 is thickened as compared with the thickness of the right cylindrical material stage during the rim manufacturing process, and the low stress generation portion 8 located inside the hump portion 7 in the rim axial direction is The thickness is reduced compared to the thickness of the cylindrical material stage.

The above-mentioned method for manufacturing a two-piece aluminum wheel comprises a first step of forming an aluminum cylindrical rim blank 1B as shown in FIG. 2 and one end of the cylindrical rim blank 1B as shown in FIG. The second step of expanding the diameter and reducing the diameter of the other end to form the rim intermediate product 1C, and the end on the expanded diameter side of the rim intermediate product 1C is drawn by a press as shown in FIG. Third step of forming one rim flange 3 at the end on the diameter expansion side and locally thickening the root R portion 6 of this rim flange, and locally thickened rim intermediate product 1D
As shown in FIG. 5, a fourth step of shaping the rim into a predetermined shape by using a split mold, and the low-stress generation portion 8 of the rim is elongated by spinning as shown in FIG. 5th step (however, the 5th step is not an indispensable step, and in some embodiments, there is no 5th step), and the rim 1 is attached to the disk 2 having the other flange 4.
And a sixth step of joining them by welding 5.

More specifically, in the first step, the flat plate 1A made of aluminum is welded into a cylindrical shape by butt-welding the winding ends, or
Or aluminum cylindrical material 1B whose outer diameter is slightly smaller than the nominal diameter of the finished rim product by cylindrical extrusion processing
To form. In the second step, as shown in FIG. 3, the cylindrical material 1B is axially compressed between the flare mold 10 and the shrink mold 11 to expand the end on the side where the rim flange is formed, and Reduce the diameter of the end that is attached to the disc.

In the third step, as shown in FIG. 4, the flare portion (the enlarged diameter portion at one end of the rim) formed in the second step is drawn between the pair of molds 12 and 13 by a scissor press to draw it. The rim flange 3 is plastically processed. Since the drawing is performed by pressing, the wall thickness can be increased or decreased, and the wall thickness of the root R portion 6 of the rim flange 3 is increased.
As a result, a thickness increase of about 10% of the thickness of the cylindrical material 1B was obtained. Conversely speaking, it is possible to reduce the amount corresponding to the increase in thickness with the original thickness of the material, which enables weight reduction, material saving, and cost reduction. In the third step, the outer diameter of the bead seat portion of the rim is about 1 to 1.5 than that of the finished rim product.
It is formed to have a value smaller by mm.

In the fourth step, as shown in FIG. 5, a shaping device composed of a split die divided into a plurality of pieces in the circumferential direction is used.
Perform shaping to give a rim shape and a perfect circle. In the shaping device of FIG. 5, the upper mold 14 has an annular shape. The lower mold shrink mold 15 (divided into three parts) moves about 3 mm toward the center in the radial direction and closely contacts each other to form an integral mold having an inner peripheral surface having a rim outer diameter dimension to form a rim flange and a rim bead seat. Shape At the same time, as the upper die cone 16 descends, the expander piece 17 (six parts) is expanded, the rim is subjected to strong pressure and plastic working on the fixed die 18 and the shrink die 15, and the rim is shaped to a prescribed size. The hump height (0.5 mm) is also stretch-molded. After the shaping, the cone 16 is lifted by about 20 mm to move the expander piece 17 toward the center by 2.8 mm. At the same time as the upper mold 14 is disengaged upward from the shrink mold 15, the shrink mold 15 is moved outward by about 3
Move mm. Then take out the product rim. Rotate the rim about 30 ° in the circumferential direction and repeat the above operation again.
In this way, it is possible to manufacture a rim with high precision in terms of dimensions and contact. When the thickness of the low stress generation portion 8 is not reduced in other steps, the thickness is reduced in the fifth step and the disc is welded in the sixth step.

Next, a different process (thickness reduction) in each embodiment will be described. In the first embodiment, in the fifth step, the low stress generating portion 8
Is reduced. That is, as shown in FIG. 6, a rim is fitted to the mandrel 19, and the tip of the rim flange is sandwiched between the clamper 20 and the mandrel 19 to fix the rim in the axial direction. Next, the spinning roller 21 spins the low stress generating portion 8 of the rim from the outer peripheral side to extend the rim to a predetermined rim length and reduce the rim thickness of the low stress generating portion.

In the second embodiment, in the first step, the low stress generating portion 8 is preliminarily reduced in thickness by making a cylindrical material from a flat plate with a groove in which the thickness of a predetermined portion is reduced. The thickness reduction due to the spinning process in the fifth step is removed. More specifically, as shown in FIG. 7, an aluminum flat plate 1A having a groove 22 in a predetermined portion (a portion corresponding to the low stress generating portion 8 axially inward of the hump portion 7 when formed into a rim) is preliminarily extruded. It is made by using a dash, and as shown in FIGS. 8 and 9,
The cylindrical rim blank 1B is manufactured by winding the groove 22 outside or inside and welding the butt ends. 10 or 11 by the second, third and fourth steps.
As shown in, a rim having the groove 22 on the outer peripheral side or the inner peripheral side is produced, and the process proceeds to the sixth step without passing through the fifth step,
Welded to a disc to make a disc wheel.

In the third embodiment, the cylindrical rim material 1B is formed in the first step, and further, on the outer circumference of this cylindrical rim material,
By reducing the thickness of the low-stress generation portion 8 in advance by using a grooved cylindrical rim material having a groove portion reduced in thickness by performing a spinning process, the thickness reduction due to the spinning process in the fifth step is removed. More specifically, as shown in FIGS. 12 and 13, a rotatable mandrel 23 is fitted with a cylindrical rim blank 1B having no groove formed therein, and a groove 25 is formed on the outer periphery of the rim by a spinning roll 24. At this time, the rim length is extended, and the groove 25 is formed in the portion where the spinning roll 24 is pressed to reduce the thickness. This reduced thickness portion corresponds to the low stress generation portion 8. Then the second,
After the third and fourth steps, the fifth step is omitted, the process proceeds to the sixth step, where it is welded to the disc to produce a disc wheel.

The fourth embodiment does not have the fifth step, and is otherwise the same as the first embodiment. As a result, the root R portion 6 of the rim flange 3 is thickened by the press, and the portion other than the root R portion 6 is thinned by that amount over the entire length of the rim.

The weight of the rim of the disc wheel manufactured by any of the above-mentioned first to fourth embodiments is as follows. However, the rim size is 16 × 8JJ and the material is A
5454-0 (aluminum alloy). That is, although the material plate thickness was 5.5 mm and the rim weight was 3.43 kg in the past, the plate was used in the rim manufactured in the fourth example (the process 5 is not performed and the low stress generating portion is not reduced). The thickness (average plate thickness excluding the R part at the root of the rim flange) is 5.0 mm, and the weight is reduced to 3.12 kg, which is 9.04% compared to the conventional one.
Will reduce the weight. In addition, in the rims manufactured in the first to third examples (there is a reduction in the low stress generation part), the plate thickness is 5.0 m.
In m, the weight is reduced to 2.72 kg, which is 2
The weight is reduced by 0.7%.

[0016]

According to the first aspect of the present invention, since the root R portion of the rim flange is thickened by the press and the low stress generating portion is thinned by the spinning process, a large amount (for example, about 2) can be obtained.
0%), wheel weight reduction, material saving. According to the invention of claim 2, since the root R portion of the rim flange is thickened by pressing and the low stress generating portion is preliminarily thinned by using the grooved flat plate, the wheel weight is significantly reduced and the material is saved. be able to. According to the invention of claim 3, the rim flange root R portion is thickened by pressing,
At the stage of the cylindrical rim material, the part corresponding to the low stress generation part in the finished product is thinned by spinning, so that the wheel weight can be significantly reduced and the material can be saved.
According to the invention of claim 4, the flange root R is formed by pressing.
Since the thickness of one part is increased and the other part is predicted to be relatively thin,
Although it is smaller than the case of the inventions of claims 1 to 3, the weight of the wheel can be significantly reduced and the material can be saved significantly (for example, about 10%).

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view of a wheel manufactured by the method of the present invention.

FIG. 2 is a perspective view of a cylindrical rim material wound with a flat plate in the first step of the method of the present invention.

FIG. 3 is a cross-sectional view showing a state in which one end is expanded and the other end is contracted in the second step of the method of the present invention.

FIG. 4 is a cross-sectional view showing a state where one end of the rim material is thickened in the third step of the method of the present invention.

FIG. 5 is a cross-sectional view showing a state in which the rim is shaped in the fourth step of the method of the present invention.

FIG. 6 is a cross-sectional view showing a state in which the outer periphery of the rim is locally spin-processed to reduce the thickness in the fifth step of the method of the present invention.

FIG. 7 is a side view of a grooved flat plate used in the first step of the second embodiment of the present invention.

8 is a cross-sectional view of a cylindrical rim material obtained by winding the flat plate with grooves of FIG. 7 with the grooves on the outer peripheral side.

9 is a cross-sectional view of a cylindrical rim material in which the grooved flat plate of FIG. 7 is wound with the groove on the inner peripheral side.

FIG. 10 is a rim cross-sectional view of the cylindrical rim material of FIG. 8 formed into a rim shape.

FIG. 11 is a rim cross-sectional view of the cylindrical rim material of FIG. 9 formed into a rim shape.

FIG. 12 is a sectional view of a cylindrical rim material used in the first step of the third embodiment of the present invention.

13 is a sectional view showing a state where the cylindrical rim material of FIG. 12 is locally subjected to spinning.

FIG. 14 is a partial cross-sectional view of a wheel manufactured by a conventional method.

[Explanation of symbols]

 1 rim 2 disc 3 rim flange 6 rim flange root R part 7 hump part 8 low stress occurrence part

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Mitsuru Ito 9 Topy Kogyo Co., Ltd. 5-4 Yonbancho, Chiyoda-ku, Tokyo

Claims (4)

[Claims] 1. An aluminum cylindrical rim material having an outer peripheral diameter slightly smaller than the nominal diameter of a finished rim product is formed by butt-welding a flat plate into a cylindrical shape by butt welding or extruding a cylindrical material. The rim intermediate product is formed by expanding one end of the cylindrical rim material by press forming and reducing the other end of the cylindrical rim material, and drawing the end on the expanded side of the rim intermediate product by pressing. One rim flange is formed at the end on the diameter expansion side, and the root R portion of the rim flange is locally thickened, and the locally thickened rim intermediate product is formed into a predetermined shape using a split mold. After shaping, the part with low stress generated on the inner side of the rim's hump in the axial direction is extended by spinning to a specified rim length, and the part that has been spun is reduced in thickness to make a finished rim. With the integrated Welded joining the finished rim on the back side of the disk, the manufacturing method of the two-piece aluminum wheel, characterized in that. 2. A flat-plate extruded material having a pre-groove at a portion corresponding to a portion having a low generated stress which is located inward of the hump portion in the axial direction when the finished rim product is wound in a cylindrical shape in the groove extending direction, The ends are butt-welded to form a cylindrical rim material of aluminum, and one end of the cylindrical rim material is expanded by press molding and the other end is contracted to form a rim intermediate product, The expansion-side end of the rim intermediate product is drawn by a press to form one rim flange at the expansion-side end, and the root R part of the rim flange is locally thickened. Forming a finished product rim by shaping a rim intermediate product that has been thickened to a predetermined shape using a split mold, and welding the finished product rim to the back side of the disc that integrally has the other rim flange, A method of manufacturing a two-piece aluminum wheel characterized by. 3. An aluminum cylindrical rim blank whose outer peripheral diameter is slightly smaller than the nominal diameter of the finished rim product is formed by butt-welding a flat plate into a cylindrical shape by butt welding or extruding the cylindrical material. Further, of the cylindrical rim material, a portion corresponding to a portion having a low generated stress that is located inward of the rim hump portion in the axial direction when the finished rim is finished is subjected to spinning to locally reduce the thickness. A cylindrical rim material having a groove on the outer periphery, wherein one end of the cylindrical rim material is expanded by press molding and the other end is contracted to form a rim intermediate product, and the rim intermediate product is expanded. Side end is formed by drawing with a press to form one rim flange at the end on the diameter expansion side, and the root R portion of the rim flange is locally thickened, and the locally thickened rim. Shape intermediate products using split molds Shape, and manufacturing method of the two-piece aluminum wheel for welding the finished rim on the back side of the disc, it is characterized with the other rim flange together. 4. An aluminum cylindrical rim material having an outer peripheral diameter slightly smaller than the nominal diameter of a finished rim product is formed by butt-welding a flat plate into a cylindrical shape by butt welding or extruding a cylindrical material. The rim intermediate product is formed by expanding one end of the cylindrical rim material by press forming and reducing the other end of the cylindrical rim material, and drawing the end on the expanded side of the rim intermediate product by pressing. One rim flange is formed at the end on the diameter expansion side, and the root R portion of the rim flange is locally thickened, and the locally thickened rim intermediate product is formed into a predetermined shape using a split mold. A method for manufacturing a two-piece aluminum wheel, comprising shaping and forming a finished product rim, and welding the finished product rim to the back side of a disc integrally having the other rim flange.