WO2018143524A1 - Die device for forming aluminum alloy cross member for vehicle - Google Patents

Abstract

The present invention relates to a die device for forming an aluminum alloy cross member for a vehicle. That is, by an aluminum alloy (TL100C) material substituting for a conventional steel material as the metallic material used in a cross member for a vehicle, weight reduction and stability of a vehicle body can be achieved at the same time. Particularly, the purpose of the present invention is to provide a progressive press die device, which is for forming the aluminum alloy cross member and can prevent the occurrence of various defects, such as folds, scratches, a burning phenomenon, spring-back, burr, and a scrap-sticking phenomenon, by establishing a progressive forming process analysis technique for the aluminum alloy plate through a forming analysis taking into account the characteristics of an aluminum alloy plate forming method, predictions of shape and thickness distribution and stress distribution for each process, predictions of forming-defects (folds, scratches, a burning phenomenon, spring-back, and the like), and the like.

Description

Molding device for forming aluminum alloy cross members for automobiles

The present invention relates to a mold apparatus for forming an aluminum alloy cross member for automobiles, and more particularly, to produce a phenomenon in which various defects such as texture, scratch, sintering, burr, etc., occur when manufacturing a cross member of an aluminum alloy material. It relates to a mold apparatus for molding aluminum alloy cross members for automobiles which can be prevented.

In recent years, the automotive industry has developed and researched eco-friendly and fuel-efficient technologies to improve the efficiency of internal combustion engines, reduce aerodynamic design, replace existing energy sources with high-efficiency energy sources, and reduce vehicle weight. Are on the trend.

In particular, the efficiency improvement technology of the engine and drive system has been widely applied to improve fuel efficiency, and eco-friendly vehicles such as electric vehicles and hybrid vehicles are being manufactured, but the disadvantage of excessive design and manufacturing costs compared to the fuel efficiency improvement effect is also required. have.

In other words, electric vehicles and hybrid vehicles are innovative technologies that can replace conventional fossil fuels, but they are more expensive than conventional vehicles with internal combustion engines because of the number of components and the weight of parts that must be added for alternative fuel applications such as batteries and electric motors. There is a disadvantage that the weight of 200 ~ 300kg increases.

Therefore, when the weight of the vehicle is reduced by 10%, the fuel efficiency is increased by about 6 to 8%. Therefore, it is preferable to apply a weight reduction technology that reduces the weight of the vehicle body to the internal combustion engine vehicle and the environment-friendly vehicle.

Therefore, in order to maximize the weight of the vehicle body, body parts made of lightweight materials such as aluminum alloy, magnesium, and carbon fiber reinforced plastics (CFRP), which have a lower specific gravity than general steel materials, are being applied.

However, although the body forming the skeleton of the vehicle can be made of aluminum alloy material, in order to connect the body and the body and replace the cross member forming the lower frame of the vehicle with the aluminum alloy material, it is necessary to maintain rigidity, to reduce warpage and to reduce external shock. There are also realistic problems that need to be addressed.

For reference, the cross member is a component that is assembled to the front floor portion of the lower seat, and is one of important parts that improves rigidity of the vehicle body, prevents warping and bending of the seat frame in the front and rear directions, prevents warpage, and ensures the stability of the occupant.

In general, a cross member of a vehicle needs high rigidity in order to prevent warpage and bending in the front, rear, left and right directions of the vehicle, and should be able to minimize the change of the shape due to external impact. However, the cross member using the high tensile strength steel sheet has a disadvantage in that it is inverse to weight reduction, and the high tensile strength steel sheet has a large weight and causes a problem of lowering fuel efficiency.

Therefore, it is preferable to manufacture the cross member using an aluminum alloy material.

However, when molding the aluminum alloy material into a cross member by using a press die, many molding defects such as delamination, scratch and dent, dent, sintering, burr, etc. of the material There is a disadvantage that occurs.

The overlapping phenomenon refers to a defect phenomenon in which the deformation and flow of the material are not uniform during partial molding of the corner portion as shown in FIG.

The scratches and dents or dents refer to a phenomenon in which scratches and dents are generated on the surface of the product by a mold apparatus for cross member forming, as shown in FIGS. 2 and 3.

The sintering phenomenon refers to a phenomenon in which a part of the material is pressed to the mold due to heat and high ductility of the aluminum alloy material due to friction between the mold and the material during press molding, which may cause a decrease in the life of the mold and product defects.

4 and 5, the burr refers to a phenomenon in which a kind of material residue occurs at the edge of the shear surface due to the ductility of the material during shear processing such as piercing, slotting, and notching of the aluminum alloy sheet.

In addition, the tensile strength of the cross-member aluminum alloy is 240MPa, and the tensile strength of the cross-member aluminum alloy is higher than that of a general aluminum alloy, so that defects such as twisting and spring back are generated when forming the cross member.

On the other hand, as a processing procedure for producing an aluminum alloy sheet material as a cross member, the piercing pores are inevitably proceeded, and the conventional mold apparatus for piercing the cross member is as shown in FIG.

Referring to FIG. 7, a conventional mold apparatus for piercing a cross member includes a die 10 having a discharge hole 12 through which a scrap is discharged and a hole penetrating when the punch is raised and lowered, and a cross mounted on the die 10. The aluminum alloy sheet material 30 for members is comprised, including the punch 20 etc. which raise and fall for piercing processing.

At this time, the diameter of the punch 20 and the inner diameter of the discharge hole 12 of the die 10 are formed to be the same.

Accordingly, the punch 20 is lowered to pierce the aluminum alloy plate 30 for the cross member, and at the same time, the scrap 32 at the piercing position forms the discharge hole 12 of the die 10. Is discharged downwards through.

However, during the piercing operation of the punch 20, friction processing heat is generated between the punch 20 and the aluminum alloy plate material 30 for the cross member, and in particular, the diameter of the punch 20 and the inner diameter of the discharge hole 12 are reduced. Due to the same process, the processing heat due to the friction between each other is greatly generated, and the processing heat generated at this time causes the scrap 32 to have an inner diameter surface of the discharge hole 12 of the die 10 and / or the surface of the punch 20. There is a disadvantage in that the pressing phenomenon, the phenomenon that the pressing of the scrapes 32 together.

When the scrap 32 is pressed against the inner surface of the discharge hole 12 of the die 10 and / or the surface of the punch 20, or if the scraps 32 are pressed against each other, it may cause mold breakage and molding defects. It will work.

The present invention has been made to solve the above-mentioned conventional problems, by replacing the metal material applied to the automotive cross member with aluminum alloy (TL100C) material instead of the existing steel material to ensure the light weight and stability of the vehicle body at the same time In particular, aluminum alloy sheet material can be formed through molding analysis considering the characteristics of aluminum alloy sheet forming method, shape and thickness distribution by process, prediction of stress distribution, molding defect (stacking, scratch, sintering phenomenon, spring back, etc.). A progressive press mold device for forming aluminum alloy cross members to prevent various defects such as cracking, scratching, sintering, spring back, burr, scrap pressing, etc. The purpose is to provide.

In order to achieve the above object, the present invention includes: a die having a discharge hole for discharging the scrap, and a punch for raising and lowering for piercing processing on the aluminum alloy plate for cross members mounted on the die, the inner diameter of the discharge hole of the die The gap is formed larger than the outer diameter of the punch to form a gap between the die's discharge hole and the outer diameter of the punch to prevent burring and scrap pressing. The outer diameter of the punch is lowered to minimize friction between the punch and the aluminum alloy sheet. It is formed of a straight surface section and the upper slope surface section, the exhaust hole of the die aluminum alloy cross member for automobiles, characterized in that formed in the upper straight surface section and the lower inclined section section in order to minimize the frictional processing heat between the scrap and the discharge hole inner diameter Provided is a mold apparatus for molding.

Preferably, the gap between burring prevention and scrap pressing prevention is characterized in that formed in 10㎛ ~ 50㎛.

In addition, the vertical height of the lower straight surface section of the punch and the vertical height of the upper straight surface section of the discharge hole is characterized in that formed in the same thickness of the aluminum alloy plate material to be processed.

In addition, the inclination angle of the upper inclined surface section of the punch and the inclined angle of the lower inclined surface section of the discharge hole is characterized in that formed in 5 ° ~ 10 °.

In particular, the surface of the punch is characterized in that the DLC coating layer is formed.

The DLC coating layer is disposed in a vacuum chamber, and then subjected to a plasma cleaning process in which an argon gas atmosphere maintains a vacuum of 3 to 50 mtorr while applying a bias voltage to the punch in the range of -150 to -1000 V. Carbon ions generated by decomposing the series gas (C6H6) by an arc discharge plasma at 3 to 50 mtorr are formed by electrically accelerated collision with a biased punch, and are coated with a thickness of 1 to 1.5 μm.

Through the above problem solving means, the present invention provides the following effects.

First, by replacing the metal material applied to automotive cross members with aluminum alloy (TL100C) material instead of the existing steel material can ensure the light weight and stability of the vehicle body at the same time, it can provide the fuel efficiency improvement effect of the light weight.

Second, by forming a molding progressive process analysis technique for aluminum alloy sheet through forming analysis considering the characteristics of aluminum alloy sheet forming method, shape and thickness distribution by each process, stress distribution prediction, molding defect prediction, etc. It can prevent various defects such as rusting, scratching, sintering, spring back, burr, scrap pressing when forming members.

1 is an image showing that the overlapping phenomenon occurs when forming an aluminum alloy sheet for a conventional cross member,

2 and 3 is an image showing that scratches and dents or dents are generated when forming an aluminum alloy sheet for a conventional cross member,

4 and 5 is an image showing that the burrs are generated when forming the aluminum alloy sheet for the existing cross member,

Figure 6 is an image showing that the spring back phenomenon occurs when forming an aluminum alloy sheet for the existing cross member,

7 is a cross-sectional view showing a mold apparatus for manufacturing a conventional cross member;

8 to 10 are cross-sectional views showing a mold apparatus for forming an aluminum alloy cross member for automobiles according to the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The present invention has the first focus on replacing the cross member for automobile with an aluminum alloy material for weight reduction and fuel efficiency improvement in place of the steel material, such as the existing high-tensile steel sheet, in particular, unlike the general aluminum plate material, the aluminum alloy excellent in strength ( TL100C) is characterized in that it is intended to manufacture a cross member.

The aluminum alloy (TL100C) has a tensile strength of 240 MPa class, and is a material obtained by alloying Al, Mg, and Si as a main component of 6000 series aluminum, the composition of which is shown in Table 1 in weight%.

Si Fe Cu Mn Mg Cr Zn Ti Al ≤ 1.50 ≤ 0.50 ≤ 0.30 ≤ 0.80 ≤ 1.00 ≤ 0.15 ≤ 0.30 ≤ 0.25 Remainder

The aluminum alloy (TL100C) is a material obtained by extruding a 6061 series aluminum alloy, followed by quenching (Solution Heat Treatment, Press Quenching), and age hardening. The initial strength of the heat-treated alloy is similar to that of the non-heat-treated alloy, It is a material whose strength has been greatly improved by the treatment process such as solution treatment, quenching, and aging, and has the appropriate characteristics as a lightweight body material due to its high strength compared to general aluminum plate materials.

Here, looking at the mold apparatus of the present invention for producing a cross member using the aluminum alloy (TL100C) plate material as follows.

8 to 10 are cross-sectional views showing a mold apparatus for forming an aluminum alloy cross member for automobiles according to the present invention, wherein 10 denotes a die.

The die 10 is a cross member of the aluminum alloy plate material 30 for processing to be seated, the discharge hole 12 for discharging scrap after processing of the aluminum alloy plate material 30 is formed through. .

In addition, a punch 20 for piercing is disposed above the die 10 in addition to a bending blade for bending the aluminum alloy plate 30.

Accordingly, the punch 20 is lowered to perform a piercing process for drilling a hole in the cross member aluminum alloy plate 30, and at the same time, the scrap 32 at the piercing position opens the discharge hole 12 of the die 10. Is discharged downwards through.

The present invention is to provide a progressive press mold apparatus for forming an aluminum alloy cross member, forming analysis considering the characteristics of the aluminum alloy sheet forming method, shape and thickness distribution by each process, stress distribution prediction, molding defects (stacking, scratch Advance process analysis method for forming aluminum alloy sheet into cross member through prediction of sintering, sintering, springback, etc. The main focus is on preventing such various defects.

To this end, according to a progressive process analysis technique for forming the aluminum alloy sheet material as a cross member as an embodiment of the present invention, the inner diameter size of the discharge hole 12 of the die 10 to the outer diameter of the punch (20) It is formed larger than that so that the gap (C) for preventing burring and preventing scraping from sticking is formed as an optimum gap between the inner diameter of the discharge hole 12 and the outer diameter of the punch 20.

Preferably, the gap (C) for preventing burring and pressing against scrap is formed to have a thickness of 10 μm to 50 μm.

When the gap C for preventing burring and preventing scraping from sticking, that is, the gap C between the inner diameter of the discharge hole 12 and the outer diameter of the punch 20 is less than 10 µm, the punch 20 is formed of an aluminum alloy sheet ( 30, the scrap 32 is pressed against the inner diameter of the discharge hole 12, as described above with reference to Figure 7, due to the processing friction heat due to the contact between the punch 20 and the discharge hole (12). Sticking or scraping 32 may be stuck together.

On the other hand, if the gap C) between the inner diameter of the discharge hole 12 and the outer diameter of the punch 20 is greater than 50 μm, the inner diameter of the piercing hole 34 of the aluminum alloy plate 30 is caused by the force when the punch 20 is lowered. The surface of the piercing hole 30 may be roughened while the part is slid downward, and burrs may occur from the inner diameter surface of the piercing hole 34 of the aluminum alloy plate 30.

In this manner, the gap between the inner diameter of the discharge hole 12 of the die 10 and the outer diameter of the punch 20 is formed as an optimum gap for preventing burring and preventing scrap from sticking, thereby forming the outer diameter of the punch 20 and discharging. It is possible to prevent direct frictional contact between the inner diameters of the holes 12 and to prevent the scrap 32 from being pressed against the inner diameter surfaces of the discharge holes 12, and the aluminum alloy plate 30 is formed by the punch 20. Burrs can be prevented from occurring when pierced.

In another embodiment of the present invention, the outer diameter of the punch 20 in order to minimize the friction between the punch 20 and the aluminum alloy plate 30 in accordance with a progressive process analysis technique for forming the aluminum alloy plate into a cross member The surface is formed to be divided into the lower straight surface section 22 and the upper inclined surface section 24.

As such, the outer diameter surface of the punch 20 is formed as the lower straight surface section 22 and the upper inclined surface section 24, so that the lower straight surface section 22 when the punch 20 pierces the aluminum alloy plate 30. ) Only friction with the aluminum alloy plate 30, the friction between the punch 20 and the aluminum alloy plate 30 during the piercing process in which the punch 20 drills the piercing hole 34 in the aluminum alloy plate (30) It is possible to minimize, thereby reducing the heat of friction work, it is possible to prevent the sticking phenomenon between the punch 20 and the aluminum alloy plate (30).

In still another embodiment of the present invention, according to a progressive process analysis technique for forming the aluminum alloy sheet into a cross member, the die 10 to minimize the heat of friction processing between the scrap 32 and the inner diameter of the discharge hole 12 The discharge hole 12 of) is divided into an upper straight surface section 14 and a lower inclined surface section 16.

As such, the inner diameter surface of the discharge hole 12 is formed into the upper straight surface section 14 and the lower inclined surface section 16, so that the punch 20 pierces the aluminum alloy plate 30 and then the piercing hole 34. When the scrap 32 in the seat is discharged through the discharge hole 12, only the upper straight section 14 comes into contact with the scrap 32, so that the heat of friction processing between the scrap 32 and the inner diameter of the discharge hole 12 It can be minimized, thereby preventing the scrap 32 is stuck to the inner diameter of the punch 20 or the discharge hole 12.

On the other hand, the upper and lower heights of the lower straight surface section 22 of the punch 20 is preferably formed to be the same as the thickness of the aluminum alloy plate 30 to be processed, the reason is that the piercing hole ( 34) is to be formed smoothly.

In addition, the upper and lower heights of the upper straight surface section 14 of the discharge hole 12 is preferably formed to be the same as the thickness of the aluminum alloy plate 30 to be processed, the reason is that the scrap 32 is the discharge hole ( Through the upper straight surface section 14 of 12) to be able to guide the discharge smoothly downward.

Preferably, the inclination angle θ of the upper inclined surface section 24 of the punch 20 and the inclined angle α of the lower inclined surface section 16 of the discharge hole 12 are 5 ° to 10 °.

At this time, when the inclination angle θ of the upper inclined surface section 24 of the punch 20 is less than 5 °, the friction between the upper inclined surface section 24 and the aluminum alloy plate 30 during the lowering for the piercing of the punch 20 is reduced. If the inclination angle α of the lower slope surface section 16 of the discharge hole 12 is also less than 5 °, the scrap 32 may rub against the lower slope surface section 16.

On the other hand, when the inclination angle θ of the upper inclined surface section 24 of the punch 20 is greater than 10 °, the weight of the punch 20 may be reduced to reduce the piercing force for the aluminum alloy plate, and the discharge hole 12 If the inclination angle α of the lower inclined surface section 16 of) is also greater than 10 °, the lower discharge direction of the scrap 32 may not be constant and may be distorted.

Meanwhile, a DLC coating layer 26 is formed on the surface of the punch 20.

The method of forming the DLC coating layer 26 on the surface of the punch 20 includes disposing the punch 20 in a vacuum chamber, and maintaining a vacuum degree of 3 to 50 mtorr in an argon gas atmosphere while simultaneously applying a bias voltage to the punch. The plasma cleaning process is applied in the range of -150 to -1000 V, and the carbon ions generated by the arc discharge plasma are decomposed by the arc discharge plasma at 3 to 50 mtorr electrically accelerated to the biased punch. The DLC coating layer 26 is preferably coated with a thickness of 1 to 1.5 μm so as to be robust against continuous punch hitting and frictional contact.

By forming the DLC coating layer 26 on the surface of the punch 20 in this way, damage to the punch surface can be significantly reduced to maximize the service life of the punch, and also the lubricity, abrasion resistance, and resistance to corrosion due to the low friction coefficient characteristics of the punch surface. By increasing the fusion property, it is possible to prevent the scrap or the like from being removed from the aluminum alloy sheet material from being deposited on the punch surface.

Meanwhile, the wear preventing coating layer may be formed in the discharge hole 12 of the die 10. The wear-resistant coating layer is sprayed into the discharge hole 12 of the die 10 by powder consisting of 96 to 98% by weight of chromium oxide (Cr ₂ O ₃ ) and ₂ to 4% by weight of titanium dioxide (TiO ₂ ). It is made of a thickness of 50 to 600㎛, and the plasma is applied to maintain the hardness of 900 to 1000HV.

The reason for applying ceramic to the discharge hole 12 of the die 10 is mainly to prevent wear and corrosion. Ceramic coating is superior to chromium plating or nickel chromium plating in corrosion resistance, scratch resistance, abrasion resistance, impact resistance and durability.

Chromium oxide (Cr ₂ O ₃ ) serves to prevent rusting by acting as a passivity layer that blocks oxygen invading into the metal.

Titanium dioxide (TiO ₂ ) is very stable physicochemically and has a high hiding power, thus becoming a white pigment. In addition, the refractive index is high, it is widely used in high refractive index ceramics. It has photocatalytic and superhydrophilic properties. Titanium dioxide (TiO ₂ ), air purification, antibacterial, harmful substance decomposition, pollution prevention function, discoloration prevention function. Titanium dioxide (TiO ₂ ) is to ensure that the anti-wear coating layer is firmly coated in the discharge hole 12 of the die 10, the foreign matter adhered to the anti-wear coating layer by decomposing and removing the damage of the anti-wear coating layer To prevent.

Here, when chromium oxide (Cr ₂ O ₃ ) and titanium dioxide (TiO ₂ ) are mixed and used, the mixing ratio thereof is titanium oxide (TiO ₂ ) 2 in 96 to 98% by weight of chromium oxide (Cr ₂ O ₃ ). It is preferable that -4 weight% is mixed.

When the mixing ratio of chromium oxide (Cr ₂ O ₃ ) is less than 96-98%, the coating of chromium oxide (Cr ₂ O ₃ ) is often broken in an environment such as a high temperature, so that the die 10 The antirust effect of the discharge hole 12 of the abruptly decreased.

When the mixing ratio of titanium dioxide (TiO ₂ ) is less than 2 to 4% by weight, the effect of titanium dioxide (TiO ₂ ) was so small that the purpose of mixing it with chromium oxide (Cr ₂ O ₃ ) is faded. That is, titanium dioxide (TiO ₂ ) decomposes and removes foreign matter adhering around the outer circumferential surface of AAAAAA to prevent the discharge hole 12 of the die 10 from being corroded or damaged. The mixing ratio is 2 to 4% by weight. If smaller, it takes a long time to decompose the attached foreign matter.

The anti-wear coating layer made of these materials is formed in the discharge hole 12 of the die 10 with a thickness of 50 to 600 µm, a hardness of 900 to 1000 HV, and a surface roughness of 0.1 to 0.3 µm. do.

This antiwear coating layer is sprayed at 50 to 600 占 퐉 by jetting the powdered powder and the gas at 1,400 ° C into the discharge hole 12 of the die 10 at a speed of about Mach 2.

If the thickness of the anti-wear coating layer is less than 50 μm, the effect of the above-described ceramic coating layer is not guaranteed. If the thickness of the anti-wear coating layer exceeds 600 μm, the above-mentioned effect is insignificant while excessive ceramic is excessive. There is a problem in that work time and material costs are wasted by application.

While the anti-wear coating layer is applied to the discharge hole 12 of the die 10, the temperature of the discharge hole 12 of the die 10 is raised, and the deformation of the discharge hole 12 of the heated die 10 is increased. The discharge hole 12 of the die 10 is cooled by a cooling device (not shown) to maintain a temperature of 150 to 200 ℃ to prevent it.

The sealing material made of chromic anhydride (CrO ₃ ) made of a metallic glass quartz system may be further coated around the wear protection coating layer. Chromic anhydride is applied around the wear protection coating layer made of chromium nickel powder as an inorganic sealing material.

Chromic anhydride (CrO ₃ ) is used in places requiring high wear resistance, lubricity, heat resistance, corrosion resistance, and releasability, and does not discolor in the air, has great durability, and has good wear resistance and corrosion resistance. As for the coating thickness of a sealing material, about 0.3-0.5 micrometer is preferable. When the coating thickness of the sealing material is less than 0.3 μm, the sealing material is easily peeled off and peeled even in a slight scratch groove, so that the above-described effects cannot be obtained. If the coating thickness of the sealing material is thick enough to exceed 0.5 μm, there are many pin holes, cracks, and the like on the plating surface. Therefore, the coating thickness of the sealing material is preferably about 0.3 to 0.5 mu m.

Therefore, since the coating layer having excellent abrasion resistance and oxidation resistance is formed in the discharge hole 12 of the die 10, the discharge hole 12 of the die 10 is prevented from being worn or oxidized, thereby extending the life of the product. .

In addition, the outer surface of the punch 20 and the die 10 may be coated with a fragrance material having a function such as treatment of respiratory diseases, thereby allowing the worker to obtain effects such as fatigue recovery and health promotion.

The fragrance material may be mixed with a functional oil, the mixing ratio of which is 95 to 97% by weight of the functional oil is mixed with 3 to 5% by weight of the functional oil, the functional oil is 50% by weight of Helichrysum oil, It consists of 50% by weight Patchouli oil.

The functional oil is preferably 3 to 5% by weight relative to the perfume. When the mixing ratio of the functional oil is less than 3% by weight, the effect is insignificant, and when the mixing ratio of the functional oil exceeds 3 to 5% by weight, the function thereof is not greatly improved while the manufacturing cost is greatly increased.

Among the functional oils, helichrysum oil includes nerol, geraniol, and linalol as main chemical elements, and is effective in antibacterial, antibacterial, antiseptic, anti-allergic, and anti-inflammatory.

 Patchouli oil oils include patchoulene, eugenol, and carvone as the main chemicals, and have excellent effects on antiseptic, antiseptic, antidepressant and skin inflammation treatment.

Since the functional oil is coated on the outer surface of the punch 20 and the die 10 can contribute to the fatigue of the worker, health promotion, and the like.

Claims (3)

A die 10 having a discharge hole 12 through which the scrap 32 is discharged, and a punch 20 which is lowered for piercing to the aluminum alloy sheet material 30 for cross members mounted on the die 10. But The inner diameter of the discharge hole 12 of the die 10 is larger than the outer diameter of the punch 20 to prevent burring and scrap pressing between the discharge hole 12 of the die 10 and the outer diameter of the punch 20. Prevention gap C is formed, In order to minimize the friction between the punch 20 and the aluminum alloy plate 30, the outer diameter surface of the punch 20 is formed of a lower straight surface section 22 and the upper inclined surface section 24, The discharge hole 12 of the die 10 is characterized in that formed in the upper straight surface section 14 and the lower inclined surface section 16 in order to minimize frictional heat between the scrap 32 and the inner diameter of the discharge hole 12. Mold apparatus for forming aluminum alloy cross members for automobiles. The method according to claim 1, The burr prevention and scrap pressing prevention gap (C) is formed to 10㎛ ~ 50㎛; The vertical height of the lower straight surface section 22 of the punch 20 and the vertical height of the upper straight surface section 14 of the discharge hole 12 are formed to be equal to the thickness of the aluminum alloy plate 30 to be processed; The inclination angle θ of the upper inclined surface section 24 of the punch 20 and the inclined angle α of the lower inclined surface section 16 of the discharge hole 12 are 5 ° to 10 °. Molding apparatus for forming aluminum alloy cross members. The method according to claim 1, A DLC coating layer 26 is formed on the surface of the punch 20; The DLC coating layer 26 is disposed in a vacuum chamber, and then subjected to a plasma cleaning process that maintains a vacuum of 3 to 50 mtorr in an argon gas atmosphere and applies a bias voltage to the punch in the range of -150 to -1000 V. Next, the carbon-based gas (C6H6) is formed by electrically accelerated collision with a biased punch of carbon ions generated by decomposition of an arc discharge plasma at 3 to 50 mtorr, and is coated with a thickness of 1 to 1.5 μm. Molding device for forming aluminum alloy cross members for automobiles.

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