KR102517694B1 - Method for manufacturing Aluminium long bush for electric vehicle battery - Google Patents

Abstract

A method for precisely forming a long bush of AL alloy material using a progressive mold unit (10) comprises: a step (A) of creating a first intermediate (31) having primary heads (37) formed at both ends of a rectangular rod material (20); a step (B) of creating a second intermediate (32) having secondary heads (38) formed at both ends of the first intermediate (31); a step (C) of creating a third intermediate (33) having an upper groove (24) formed at one end of the second intermediate (32); a step (D) of creating a fourth intermediate (34) having a lower groove (26) formed at the other end of the third intermediate (33); a step (E) of creating a fifth intermediate (35) having annular jaws (28) formed at both ends of the fourth intermediate (34); and a step (F) of shaping all dimensions of the fifth intermediate (35) to conform to standards to create the final product (30). The manufacturing method forms AL alloy bushings of a slender structure forming a battery pack of an electric vehicle through progressive style forging processing in a mass production site, thereby improving quality and productivity.

Description

Long bush precision molding manufacturing method of AL alloy material of electric vehicle battery structure {Method for manufacturing Aluminum long bush for electric vehicle battery}

The present invention relates to the manufacture of electric vehicle parts, and more particularly, to a long bush precision molding manufacturing method of an AL alloy material of an electric vehicle battery structure for forming some parts constituting an electric vehicle battery pack by forging.

In response to global eco-friendly energy policies, the proportion of electric vehicles that replace fossil fuel vehicles is rapidly increasing in the automobile sector. Electric vehicles have a very high proportion of battery structures that play the role of gasoline/diesel engines, and an integrated battery pack is composed of a number of modules in which unit cells are integrated. Since electric vehicles are highly dependent on battery performance, many lightweight materials are used to improve fuel efficiency. For example, long bushes made of AL alloy are used in the battery structure, and mass production technology is urgently needed to secure quality and productivity like other parts.

As prior art documents that can be referred to in this regard, Korean Patent Publication No. 2009-0005565 and Korean Patent Registration No. 0667235 may be referred to.

The former cuts the metal bar material to form a through hole in the center of the inside and a flange shape on the upper part of the outer circumferential surface, and the lower part of the outer circumferential surface forms a taper by cold multi-stage forging. And a threaded hole is formed as an inner through hole. Therefore, even if a metal material with high ductility is used, the effect of improving fastness, productivity, and precision is expected.

The latter is a step of inserting the raw material into the mold, applying the raw material to hydraulic pressing of the upper punch and the lower punch, forming upper and lower holes isolated by the reinforcement inside the raw material, and trimming the obtained forged product It includes the step of piercing using the skin to remove the extra flesh. Therefore, it is expected that the metal flow will improve mechanical properties, reduce material costs, and ensure mass production.

However, according to the above prior literature, it is insufficient to be applied to processing both ends of an elongated bushing having a length greater than its diameter, and thus shows room for improvement.

Korean Patent Laid-open Publication No. 2009-0005565 "Non-cutting metal insert type bush, manufacturing apparatus and method for non-cutting metal insert type bush" (Publication date: 2009.01.14.) Korean Patent Registration No. 0667235 "Method of manufacturing track link bush with improved mechanical properties" (Publication date: 2006.07.03.)

An object of the present invention to improve the above conventional problems is an AL alloy material of an electric vehicle battery structure for forming an AL alloy bushing of a long structure constituting a battery pack of an electric vehicle by progressive forging at a mass production site. It is to provide a long bush precision molding manufacturing method.

In order to achieve the above object, the present invention is a manufacturing method for precision forming a long bush of AL alloy material with a progressive mold unit: (A) generating a first intermediate member having a primary head at both ends of a rectangular bar member; (B) generating a second intermediate member having secondary heads at both ends of the first intermediate member; (C) generating a third intermediate member having an upper end groove at one end of the second intermediate member; (D) generating a fourth intermediate member having a bottom groove at the other end of the third intermediate member; (E) generating a fifth intermediate member having annular jaws at both ends of the fourth intermediate member; And (F) forming a finished product by shaping the overall dimensions of the fifth intermediate member to meet the standard; characterized in that it comprises a.

As a detailed configuration of the present invention, the rectangular bar is characterized in that an Al-Mg-Si-based alloy or an Al-Cu-Mg-Mn-based alloy is used, and the physical properties are differentiated in a certain area.

As a detailed configuration of the present invention, the secondary head of (B) is characterized in that the central flat portion is increased and the edge curved portion is reduced compared to the primary head.

As a detailed configuration of the present invention, in the step (C), the upper groove is characterized in that it is formed longer than the groove length of the finished product.

As a detailed configuration of the present invention, in the above steps (A) to (D), it is characterized in that the roundness of the edges remains the same.

As a detailed configuration of the present invention, it is characterized by causing a gradual increase from the above steps (C) to (E) to the entire length of the finished product.

As a detailed configuration of the present invention, it is characterized by causing a gradual increase from the above steps (A) to (F) to the entire width of the finished product.

As described above, according to the present invention, there is an effect of improving quality and productivity by molding the AL alloy bushing of the elongated structure constituting the battery pack of the electric vehicle by progressive forging at the mass production site.

1 is a schematic diagram of a mold unit applied to the method according to the present invention
Figure 2 is a schematic diagram showing the main steps of the method according to the present invention
Figure 3 is an enlarged view of a mold unit in some stages according to the present invention
Figure 4 is a schematic diagram showing the main dimensions of the method according to the present invention

Hereinafter, embodiments of the present invention will be described in detail based on the accompanying drawings.

The present invention proposes a manufacturing method for precisely forming a long bush of AL alloy material with a progressive mold unit (10). It is premised on the technology of forging a long bush of AL alloy material for mounting electric vehicles, but is not necessarily limited thereto.

Referring to FIG. 1, a die member 11, a punch member 13, a transfer table 15, and the like constituting the progressive mold unit 10 are shown. The die member 11 has adjacent individual dies for six processes. The punch member 13 has adjacent individual punches for six processes. The transfer table 15 simultaneously transfers the intermediate material, which is a workpiece in each die, to a subsequent process. Punch members 13 may be disposed on both sides of the die member 11, and the die member 11 and the punch member 13 may be vertically or horizontally disposed. The die member 11 and the punch member 13 are in close contact with the workpiece via a bush made of SKD (cold alloy tool steel) material.

Referring to Figures 1 and 2, it shows a process in which the rectangular bar 20 is molded into a finished product 30 through six processes. The finished product 30 has a round 22 on the outer circumferential surface, an upper groove 24 at one end, a lower groove 26 at the other end, and annular protrusions 28 at both ends. The overall length (L1) of the finished product 30 disclosed in the present invention is 123.6 mm, the overall width (W1) is 9.0 mm, the groove length (L2) is 18.0 mm, the jaw length (L3) is 2 mm, and the jaw outer diameter (W3) ) is exemplified by 8.7 mm.

At this time, the rectangular bar 20 can be selected from among quadrangular, hexagonal, and octagonal cross-sections, but does not exclude circular or elliptical cross-sections.

Referring to FIG. 3 , a fourth intermediate material 34, a fifth intermediate material 35, and a finished product 30 are respectively shown in the portion where the fourth to sixth processes of the mold unit 10 are processed. Based on the die member 11, it is possible to place a punch of reference numeral 13A on one side and a punch and/or knockout pin of 13B on the other side.

Referring to FIG. 4, steps (A) to (F) are sequentially performed in the first process (#1) to the sixth process (#6) through the progressive mold unit 10 applied to the present invention. .

Step (A) according to the present invention is a process of generating a first intermediate member 31 having a primary head 37 at both ends of the rectangular bar member 20. The square bar 20 is put in as it is in a state where both ends are cut. In this step, pressing force is applied to both ends of the square bar 20 to form primary heads 37 of the same standard.

Step (B) according to the present invention goes through the process of creating a second intermediate member 32 having a secondary head 38 at both ends of the first intermediate member 31. In this step, secondary heads 38 of the same standard are formed at both ends of the first intermediate member 31 . The length of the first intermediate member 31 and the second intermediate member 32 is reduced within a set range, respectively.

Step (C) according to the present invention goes through the process of creating a third intermediate member 33 having an upper end groove 24 at one end of the second intermediate member 32. In this step, the upper groove 24 of the set length (depth) is formed only at one end of the second intermediate member 32. The third intermediate member 33 is created while the flow of the material is induced in the form of backward extrusion at one end of the second intermediate member 32 .

Step (D) according to the present invention is a process of creating a fourth intermediate member 34 having a bottom groove 26 at the other end of the third intermediate member 33. In this step, the fourth intermediate member 34 is created while the flow of the material is induced in the form of forward extrusion at the other end of the third intermediate member 33. At the same time, the densification of the tissue of the already formed upper groove 24 proceeds. Of course, it is also possible to integrate step (C) into step (D) depending on the standard of the finished product (30).

Step (E) according to the present invention goes through the process of creating a fifth intermediate member 35 having annular jaws 28 at both ends of the fourth intermediate member 34. In this step, the ends of the upper groove 24 and the lower groove 26 are partially reduced to form an annular jaw 28. The upper groove 24 and the lower groove 26 of the fourth intermediate member 34 maintain the rectangular cross section of the rectangular bar 20, but the annular jaw 28 of the fifth intermediate member 35 is deformed into a circular cross section.

Step (F) according to the present invention undergoes a process of generating the finished product 30 by shaping the overall dimensions of the fifth intermediate member 35 to meet the standard. In this step, the fifth intermediate member 35 is a finished product whose main dimensions such as overall length (L1), overall width (W1), groove length (L2), jaw length (L3), and jaw outer diameter (W3) meet the standard ( 30) is created.

Referring to FIG. 4, the dimensional variation of the intermediate material in steps (A) to (F) of the present invention is illustrated, but is not limited thereto.

As a detailed configuration of the present invention, the rectangular bar 20 is characterized in that an Al-Mg-Si-based alloy or an Al-Cu-Mg-Mn-based alloy is used, and the physical properties are differentiated in a certain area.

Although omitted from the illustration, an Al-Mg-Si-based alloy or an Al-Cu-Mg-Mn-based alloy is preferred as a component for mounting an electric vehicle in consideration of light weight, high strength, corrosion resistance, as well as toughness and forging formability. Mg and Si impart high yield strength in forging, Cu contributes to strength enhancement through solid solution strengthening, and Mn induces crystal grain refinement and strength enhancement. Of course, it is also possible to further add other components depending on the use of the finished product 30 .

In any case, the rectangular bar 20 is preferably subjected to at least a partial T6 hardening heat treatment to increase strength.

In FIG. 4, the physical properties may be differentiated in the region indicated by the symbol A1 at the top of the intermediate material. Differentiation of physical properties means setting different thermal and physicochemical conditions in the forging process. Accordingly, the upper groove 24 may exhibit superiority over the lower groove 26 in terms of durability.

As a detailed configuration of the present invention, the secondary head 38 of (B) is characterized by a structure in which a central flat portion is increased and an edge curved portion is reduced compared to the primary head 37.

2 and 4, the first head 37 shows a flat part at the upper part of the hemispherical curved part, but the second head 38 has a curved part at a part of the edge while increasing the flat part at most of the upper part. The first intermediate member 31 is reduced to a length of 111 mm and the second intermediate member 32 is reduced to a length of 110.5 mm. Accordingly, the organization of the first intermediate member 31 and the second intermediate member 32 is densified at both ends, so that the durability of the upper groove 24, the lower groove 26, and the annular jaw 28 of the subsequent process is increased. contribute to

As a detailed configuration of the present invention, in the step (C), the upper groove 24 is characterized in that it is formed longer than the groove length L2 of the finished product 30.

In FIG. 4, the groove length L2 of the finished product 30 is 18.0 mm, while the groove length of the third intermediate member 33 is set to 18.02 mm. This is to consider the gradual increase of the overall length L1 and/or the overall width W1 through the subsequent steps (D), (E), and (F). Otherwise, defects such as cracks, scratches, and burrs may occur.

As a detailed configuration of the present invention, in the steps (A) to (D), the round 22 of the edge is characterized in that it remains the same.

In Fig. 4, the round 22 of the edge remains the same at 1.6 mm in steps (A) to (D) and then reduced and maintained at 1.5 mm in steps (E) and (F). In steps (A) to (D), it is good to keep the round 22 constant to minimize the flow of unnecessary material at the edge of the intermediate member.

As a detailed configuration of the present invention, it is characterized by causing a gradual increase from the above steps (C) to (E) to the entire length (L1) of the finished product (30).

4, the length of the third intermediate member 33 is increased to 117 mm, the length of the fourth intermediate member 34 is increased to 122 mm, and the length of the fifth intermediate member 35 is increased to 123.6 mm. The entire length L1 of the finished product 30 is maintained as the length of the fifth intermediate member 35. This increase in length is related to the formation of the upper groove 24, the lower groove 26, and the annular jaw 28.

As a detailed configuration of the present invention, it is characterized by causing a gradual increase from the above steps (A) to (F) to the entire width (W1) of the finished product (30).

4, the width of the first intermediate member 31 is 8.65 mm, the width of the second intermediate member 32 is 8.7 mm, the width of the third intermediate member 33 is 8.8 mm, and the width of the fourth intermediate member 34 is 8.85 mm. mm, the width of the fifth intermediate member 35 is increased to 8.9 mm, and the width of the finished product 30 is increased to 9.0 mm. In step (E), the annular jaw 28 of the fifth intermediate member 35 has a diameter of 8.7 mm and a jaw length L3 of 2.0 mm. Of course, the length increase and the width increase of the intermediate member are set to have connectivity. Deviating from this linkage increase in dimension may cause defects such as cracks, scratches, and burrs.

The present invention is not limited to the described embodiments, and it is obvious to those skilled in the art that various modifications and variations can be made without departing from the spirit and scope of the present invention. Therefore, such variations or modifications should fall within the scope of the claims of the present invention.

10: mold unit 11: die member
13: punch member 15: transfer table
20: square bar 22: round
24: upper groove 26: lower groove
28: annular jaw 30: finished product
31~35: intermediate material 37: primary head
38: 2nd head L1: overall length
L2: Groove length L3: Chin length
W1: Overall width W3: Jaw outer diameter

Claims (7)

In the manufacturing method of precision molding the long bush of AL alloy material with the progressive mold unit (10):
(A) generating a first intermediate member 31 having a primary head 37 at both ends of the square bar member 20; (B) generating a second intermediate member 32 having secondary heads 38 at both ends of the first intermediate member 31; (C) creating a third intermediate member 33 having an upper end groove 24 at one end of the second intermediate member 32; (D) creating a fourth intermediate member 34 having a bottom groove 26 at the other end of the third intermediate member 33; (E) generating a fifth intermediate member 35 having annular jaws 28 at both ends of the fourth intermediate member 34; And (F) forming the finished product 30 by shaping the overall dimensions of the fifth intermediate member 35 to meet the standard; including,
The secondary head 38 of (B) has a structure in which the flat portion in the center is increased and the curved portion at the edge is reduced compared to the primary head 37,
In the step (C), the upper groove 24 is formed longer than the groove length L2 of the finished product 30,
In the steps (A) to (D), the round 22 of the edge of the entire outer circumference of the intermediate member remains the same, and the round 22 is reduced in the steps (E) and (F),
Inducing a gradual increase from the above steps (C) to (E) to the total length (L1) of the finished product (30),
Longbush precision molding manufacturing method of AL alloy material of electric vehicle battery structure, characterized in that it causes a gradual increase from the steps (A) to (F) to the overall width (W1) of the finished product (30). The method of claim 1,
The square bar 20 uses an Al-Mg-Si-based alloy or an Al-Cu-Mg-Mn-based alloy, and the long bush precision of the AL alloy material of the electric vehicle battery structure, characterized in that the physical properties are differentiated in a certain area molding manufacturing method. delete delete delete delete delete

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