JPH11192968A - Center pillar reinforcing material forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a center pillar reinforcing material in a prescribed shape without causing any fracture in a local overhang forming part by irradiating a high-energy beam such as a laser beforehand to a punch comer part which is locally subjected to an angular head overhang deformation, forming a soft part, and then hydraulically forming it. SOLUTION: A center pillar reinforcing material having a locally angular head overhang shape is hydraulically formed using an aluminium alloy extrusion material. In this case, a high energy beam 10 such as a laser is irradiated to a region 4 subjected to angular head overhang deformation so as to be melted, solidified and formed into a soft part 5. When the punch comer R of the angular head overhang shape and the punch comer section R are set to Cp and Rp respectively, and if Cp>=Rp or if Cp<Rp, then semicircles of the diameter 2<1/2> .Cp of semicircles of the diameter 2<1/2> .Rp are formed in four punch comer parts of the angular head overhang part respectively in such a range that the diameter of the semicircle forms at 45 deg. to the punch ridge 8.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a center pillar reinforcing material, and more particularly, to a method for forming a reinforcing material for a center pillar, which is a structural component of a vehicle body, by extruding an aluminum alloy.

[0002]

2. Description of the Related Art As a conventional method for forming a center pillar reinforcing material by using an extruded aluminum alloy, there has been a method shown in FIGS. This prior art is based on a heat-treated extruded aluminum alloy 1
Is sandwiched between an upper mold 7a and a lower mold 7b, and both ends of the extruded material 1 are pushed in while applying internal pressure through the liquid 6 to form a predetermined shape.

[0003]

However, in such a conventional method for forming a center pillar reinforcing material, a portion which locally undergoes overhang deformation is subjected to material inflow even if both ends of the extruded material are pushed in during molding. Because of this, the overhang height depends on the elongation limit of the material.However, the tempered aluminum alloy has a low elongation limit, making it difficult to form a locally overhang shape. there were.

The present invention has been made in view of such a conventional problem, and a method of forming a center pillar reinforcing material which can be formed into a predetermined shape without causing breakage of a locally overmolded portion. The purpose is to provide.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, according to the present invention, when a center pillar reinforcing material is formed, an aluminum alloy extruded material is preliminarily subjected to a laser beam or the like within a range where the aluminum alloy extruded material is locally deformed by corner head overhang. It is characterized in that it is irradiated with an energy beam, melted and solidified to form a soft part, and then formed by hydraulic forming.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the method for forming a center pillar reinforcing material according to the present invention will be described below in detail with reference to the accompanying drawings. 1 to 6 are views showing an embodiment of a center pillar reinforcing material forming method according to the present invention.

First, the configuration will be described. When the center pillar reinforcing material 2a having the locally protruded corner shape 3 is formed by the hydraulic forming method using the aluminum alloy extruded material 1, a high energy such as a laser or the like is preliminarily placed in a range 4 to be subjected to the protruded corner deformation. Irradiation with beam 10
The solidified portion 5 is formed in advance by solidification.

[0008] The range of formation of the soft portion is as follows. When the punch corner R of the corner-overhanging shape is Cp and the punch cross section R is Rp, if Cp ≧ Rp, a semicircle having a diameter √2 · Cp is defined as Cp <
In the case of Rp, a semicircle having a diameter of √2 · Rp is transferred to the four punch corners of the corner projection, and the diameter of the semicircle is the punch ridge line 8.
Is formed at an angle of 45 ° with respect to.

The melting portion provided as the soft portion 5 is formed to have a melting depth of not less than ／ of the thickness of the material.

The extruded material in which the soft portion 5 is formed in advance is sandwiched between the upper mold 7a and the lower mold 7b, and is formed into a center pillar reinforcing material 2a having a predetermined shape while applying both ends while applying hydraulic pressure. .

Next, the operation of the embodiment will be described. FIG. 7 shows the behavior of the material 9 at the corner head overhang during the hydroforming. In the hydroforming, a medium pressure is applied from the early stage to the middle stage of the processing, and the part is formed into a rough shape, and a high pressure is applied in the latter half of the processing to form a detailed shape. During high-pressure molding in the latter stage of the processing, the amount of strain in the punch corner area of the corner projection is increased, and a material having a small elongation limit is broken.

[0012] Although the tempered heat-treated aluminum alloy extruded material has high strength, the material has a low elongation limit, so that it is difficult to obtain a locally extended shape.

Therefore, by forming the soft portion in a range that undergoes overhang deformation in the later stage of processing, overhanging property can be improved and breakage during high-pressure forming can be prevented. However, if a soft part is formed over the entire area of the corner protrusion, only the soft part forming part may be deformed and broken during medium pressure forming from the initial stage to the middle stage, so the soft part forming range is limited. There is a need to.

As a result of examining a range where the amount of strain is large by a square head overhang test, the strain at the four punch corners is large, and the range is Cp ≧ Cp when the punch corner R is Cp and the punch section R is Rp. If Rp, diameter√2 ・
Within the area of the semicircle of Cp, or Cp <Rp, the diameter of the semicircle was 45 ° with respect to the punch ridge line 8 within the area of the semicircle of diameter√2 · Rp.

By limiting the soft portion within the above range, the phenomenon that only the soft portion is deformed during the intermediate pressure forming from the initial stage to the middle stage is prevented, and the overhang is formed during the high pressure forming in the later stage of processing. It became possible.

[0016]

As described above in detail, according to the present invention, when the center pillar reinforcing member is formed by using an aluminum alloy extruded material, the portion which is locally subjected to the corner head overhang deformation is formed. The punch corner is irradiated with a high-energy beam such as a laser in advance to form a soft part, and then the hydraulic forming method is used to form the part into a predetermined shape without breaking the overhang part It became possible to do.

[Brief description of the drawings]

FIG. 1 is a diagram showing an aluminum alloy extruded material as a center pillar reinforcing material.

FIG. 2 is a view showing a center pillar reinforcing member having a locally extended shape.

FIG. 3 is a diagram showing a soft part forming state in the present invention.

FIG. 4 is a view showing a state in which a member having a locally protruding shape according to the present invention is hydraulically formed.

FIG. 5 is a diagram showing an enlarged and cross-sectional shape of a local overhang portion.

FIG. 6 is a range showing a formation range of a soft part.

FIG. 7 is a diagram showing a molding state of an overhang portion during hydraulic molding.

FIG. 8 is a view showing a state where an extruded material is put in a mold in a conventional structure.

FIG. 9 is a view showing a state where a conventional structure is formed by applying hydraulic pressure.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 Aluminum alloy extruded material 2a Center pillar reinforcing material having local overhanging shape 2b Center pillar reinforcing material of conventional structure without local overhanging shape 3 Local overhanging shape 4 Range subject to local overhanging 5 Soft part forming portion 6 Liquid for hydraulic forming 7a Upper die for hydraulic forming 7b Lower die for hydraulic forming 8 Punch ridge line 9 Material 10 High energy beam

Claims (2)

[Claims] When manufacturing a center pillar reinforcing material for an automobile part from an aluminum alloy extruded material, (1) a part which is locally subjected to corner head overhang deformation, a punch corner R of the square head overhang part is Cp, and a punch cross section. When R is Rp, a semicircle having a diameter √2 · Cp if Cp ≧ Rp is formed in a range in contact with the four punch corners, and Cp <
If Rp, a soft part is formed in a semicircular shape having a diameter of √2 · Rp. (2) A center pillar reinforcing material forming method characterized by forming in a process of forming into a component shape by hydraulic bulge forming. 2. The center pillar reinforcing material forming method according to claim 1, wherein the soft part is formed by irradiating a high energy beam such as a laser with a molten bead to a depth of ２ or more of a plate thickness. A method for molding a center pillar reinforcing material.