A battery box manufacturing process

Abstract

This invention relates to the field of automotive mold stamping technology and provides a battery box manufacturing process, including the following steps: a drawing process, a forming process, a first trimming and punching process, a second trimming and punching process, and a shaping process. The battery box manufacturing process provided by this invention allows a flat sheet to be drawn and deformed through the closing process of upper and lower dies, ultimately presenting the shape of a punch product. Due to the risk of cracking in some areas of the part formed in one step, the shape of this area is gradually flattened in the drawing process. In the subsequent forming process, special forming upper and lower dies are designed to enlarge the concave R-angle at the gradually diminishing sidewall of the product and form it again. Furthermore, the blank holder surface is 3mm higher than the flange, retaining a portion of the area to be formed and straightened in the subsequent forming process, resulting in more thorough straightening, more stable forming, and ensuring the flatness of the flange while controlling the risk of wrinkling.

Description

Technical Field

[0001] This invention relates to the field of automotive mold stamping technology, and in particular to a battery box manufacturing process. Background Technology

[0002] With the emergence of new energy vehicles and their explosive growth in recent years, the mold industry is facing new challenges. In the manufacturing process of battery boxes, due to the material properties of battery boxes, they have high tensile strength, thick plates, and large volume, which makes it difficult to control the rebound of existing battery boxes. Summary of the Invention

[0003] To address the limitations of existing battery box designs and difficulties in controlling rebound, the present invention provides the following technical solution:

[0004] A battery box manufacturing process, which includes the following steps in sequence:

[0005] The drawing process includes an upper drawing die and a lower drawing die. The upper drawing die is equipped with an upper pressure plate mounted by an elastic device, and the lower drawing die is equipped with a blank holder mounted by an elastic device. When the upper and lower drawing dies are closed, they are open. The battery box sheet is placed between the upper and lower drawing dies. The upper drawing die moves towards the battery box sheet and the lower drawing die. The upper pressure plate and the lower drawing die close first, and then the blank holder closes with the upper drawing die to generate drawing beads. Finally, the drawing process is completed.

[0006] Forming process: The forming process mold includes an upper forming mold and a lower forming mold. The upper forming mold is equipped with an upper pressure plate installed by an elastic device, and the lower forming mold is equipped with a lower pressure plate installed by an elastic device. When the upper forming mold moves downward and contacts the battery box material, the upper pressure plate presses on the battery box material and stops moving. The upper forming mold continues to move, while the lower forming mold remains stationary. The lower pressure plate moves downward under the pressure of the upper forming mold. The battery box material is formed by the concave mold and the convex mold on the lower forming mold.

[0007] The local R-angle areas of the upper and lower drawing dies are enlarged, and the blank holder surface is 3mm higher than the flange, so that a part of the area is retained for forming and straightening in the forming process.

[0008] Trimming and punching process: This includes a first trimming and punching process and a second trimming and punching process. The battery box material is trimmed and punched using two trimming and punching processes.

[0009] First trimming and punching process: The battery box sheet is placed between the first trimming and punching upper die and the first trimming and punching lower die. The first trimming and punching upper die moves towards the battery box sheet and the first trimming and punching lower die. The first trimming and punching upper die punches the battery box sheet to complete the first trimming and punching process.

[0010] Second trimming and punching process: The battery box sheet is placed between the second trimming and punching upper die and the second trimming and punching lower die. The second trimming and punching upper die moves towards the battery box sheet and the second trimming and punching lower die. The second trimming and punching upper die punches the battery box sheet to complete the second trimming and punching process.

[0011] Shaping process: The battery box sheet is placed between the upper and lower shaping dies. The upper shaping die moves towards the battery box sheet and the lower shaping die, and the upper shaping die stamps the battery box sheet to complete the shaping process.

[0012] During the drawing process, the feeding direction of the battery box sheet is controlled on the side of the upper and lower drawing dies.

[0013] The aforementioned elastic device uses a nitrogen spring.

[0014] In the drawing process, a drawing step is added to the battery box sheet.

[0015] The first trimming and punching lower die is provided with a first trimming unloading hole and a first punching unloading hole, and the second trimming and punching lower die is provided with a second trimming unloading hole and a second punching unloading hole. A waste collection trough is provided below the first trimming unloading hole, the first punching unloading hole, the second trimming unloading hole and the second punching unloading hole.

[0016] The beneficial effects of the technical solutions provided in the embodiments of the present invention include at least the following:

[0017] 1. The battery box manufacturing process provided by this invention involves a drawing process in which a flat sheet is drawn and deformed through the closing process of upper and lower dies, ultimately presenting the shape of a punch product. Since the shape of a certain area of ​​the part is formed in one step, there is a risk of cracking. Therefore, the shape of this area is gradually flattened in the drawing process. In the subsequent forming process, special forming upper and lower dies are designed to enlarge the concave R-angle at the gradually decreasing part of the product side wall and form it again. Furthermore, the blank holder surface is 3mm higher than the flange, which preserves a part of the area to be formed and straightened in the subsequent forming process. The straightening is more thorough, the forming is more stable, and the flatness of the flange is guaranteed, controlling the risk of wrinkling.

[0018] 2. The battery box manufacturing process provided by the present invention adopts semi-open drawing. Semi-open drawing firstly greatly improves the utilization rate, and during the drawing process, the feeding direction of the sheet is controlled on the left and right sides of the mold, which greatly reduces the internal stress on the open side. The stress released during subsequent trimming is small, which reduces the springback caused by the stress released during trimming.

[0019] 3. The battery box manufacturing process provided by this invention employs a double-plate drawing process. The upper platen is movable vertically, with pressure provided by a nitrogen spring. After the upper and lower dies close, they need to separate. The nitrogen spring lifts the upper platen, initially closing it with the lower drawing die and maintaining horizontal alignment with the blank holder. This design prioritizes the closing of the upper platen and lower drawing die to ensure the flatness of the battery box surface, preventing it from being affected during the drawing process. Subsequently, the blank holder closes with the upper drawing die, generating draw beads, and finally, the drawing process is completed. Drawing curbs are added locally to control the local material feed speed and prevent wrinkling during the drawing process. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a flowchart of a battery box manufacturing process provided by an embodiment of the present invention.

[0022] Figure 2 This is a bottom view of the drawing die in this invention;

[0023] Figure 3 This is a top view of the lower drawing die in this invention;

[0024] Figure 4 yes Figure 3 Enlarged view of a portion of point A in the middle;

[0025] Figure 5 A schematic diagram of the battery box sheet structure after the drawing process in this invention;

[0026] Figure 6 A schematic diagram of the flat sheet drawing process in the drawing process of this invention;

[0027] Figure 7 This is a bottom view of the forming upper mold in this invention;

[0028] Figure 8 This is a top view of the forming lower mold in this invention;

[0029] Figure 9 yes Figure 8 Enlarged view of section B in the middle;

[0030] Figure 10 A schematic diagram of the battery box plate structure after the forming process in this invention;

[0031] Figure 11 A schematic diagram of the flat plate forming process in the forming step of this invention;

[0032] Figure 12 This is a bottom view of the first trimming and punching die in this invention;

[0033] Figure 13 This is a top view of the first trimming and punching die in this invention;

[0034] Figure 14 A schematic diagram of the battery box sheet structure after the first trimming and punching process in this invention;

[0035] Figure 15 This is a bottom view of the second trimming and punching upper die in this invention;

[0036] Figure 16 This is a top view of the second trimming and punching die in this invention;

[0037] Figure 17 A schematic diagram of the battery box sheet structure after the second trimming and punching process in this invention;

[0038] Figure 18 This is a bottom view of the upper shaping mold in this invention;

[0039] Figure 19 This is a top view of the lower forming mold in this invention;

[0040] Figure 20 A schematic diagram of the battery box plate structure after the shaping process in this invention.

[0041] In the attached diagram, 1 is the upper drawing die, 2 is the lower drawing die, 3 is the battery box sheet after the drawing process, 4 is the upper pressure plate, 8 is the blank holder, 9 is the drawing sill, 10 is the opening, 11 is the upper forming die, 12 is the lower forming die, 13 is the battery box sheet after the forming process, 14 is the lower pressure plate, 15 is the partial R-angle area, 16 is the flange, 17 is the first trimming and punching upper die, 18 is the first trimming and punching lower die, 19 is the first upper die cutter block, 20 is the first punching punch, and 21 is the first trimming unloading hole. 22. First punching and unloading hole, 23. Unloading chute, 24. Battery box sheet after the first trimming and punching process, 25. Second trimming and punching upper die, 26. Second trimming and punching lower die, 27. Second upper die cutter block, 28. Second punching punch, 29. Second trimming and unloading hole, 30. Second punching and unloading hole, 31. Battery box sheet after the second trimming and punching process, 32. Shaping upper die, 33. Shaping lower die, 34. Shaping cutter block, 35. Battery box sheet after the shaping process. Detailed Implementation

[0042] The technical solution of the present invention will now be described with reference to the accompanying drawings.

[0043] In embodiments of the present invention, words such as "exemplarily," "for example," etc., are used to indicate that something is an example, illustration, or description. Any embodiment or design described as "exemplary" in the present invention should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of the word "exemplary" is intended to present the concept in a concrete manner. Furthermore, in embodiments of the present invention, the meaning expressed by "and / or" can be both, or either one.

[0044] In the embodiments of this invention, the terms "image" and "picture" may sometimes be used interchangeably. It should be noted that, without emphasizing the distinction between them, they convey the same meaning. Similarly, the terms "of," "corresponding (relevant)," and "corresponding" may sometimes be used interchangeably. It should be noted that, without emphasizing the distinction between them, they convey the same meaning.

[0045] In this embodiment of the invention, sometimes a subscript such as W1 may be written in a non-subscript form such as W1. When the difference is not emphasized, the meaning they express is the same.

[0046] To make the technical problems, technical solutions and advantages of the present invention clearer, a detailed description will be given below in conjunction with the accompanying drawings and specific embodiments.

[0047] like Figure 1 As shown, this embodiment of the invention provides a battery box manufacturing process, which includes the following steps in sequence: a drawing process, a forming process, a first trimming and punching process, a second trimming and punching process, and a shaping process.

[0048] like Figure 2-6 As shown, in the drawing process: the battery box sheet (initially a flat sheet) is placed between the upper drawing die 1 and the lower drawing die 2. The upper drawing die 1 moves towards the battery box sheet and the lower drawing die 2. The upper drawing die 1 stamps the battery box sheet to complete the drawing process.

[0049] The upper drawing die 1 is set as a concave die, and the lower drawing die 2 is set as a convex die. The upper drawing die 1 is provided with an upper pressure plate 4 installed by an elastic device, and the lower drawing die 2 is provided with a pressure ring 8 installed by an elastic device. When the upper drawing die 1 moves downward and contacts the battery box material, the upper pressure plate 4 presses on the battery box material and stops moving. The upper drawing die 1 continues to move, while the lower drawing die 2 remains stationary. The pressure ring 8 moves downward under the pressure of the upper drawing die 1. The battery box material is drawn by the concave die and the convex die on the lower drawing die 2.

[0050] When the upper drawing die 1 and the lower drawing die 2 are closed, an opening 10 is provided to realize the semi-opening 10 drawing of the battery box sheet. The semi-opening 10 drawing greatly improves the utilization rate. The feeding direction of the battery box sheet is on the side of the upper drawing die and the lower drawing die. The above-mentioned elastic device adopts a nitrogen spring.

[0051] like Figure 6 As shown, during the closing process of the upper drawing die 1 and the lower drawing die 2, the upper pressure plate 4 initially closes with the lower drawing die 2, and the upper pressure plate 4 and the pressure ring 8 remain horizontally aligned. The purpose of designing the upper pressure plate 4 and the lower drawing die 2 to close first is to ensure the flatness of the battery box surface, so that it is not affected during the drawing process. Subsequently, the pressure ring 8 closes with the upper drawing die 1 to generate drawing ribs, and finally the drawing forming process is carried out. In the drawing process, a drawing sill 9 is added locally to control the local material feeding speed and prevent wrinkling during the drawing process.

[0052] Battery box sheet material after drawing process, such as Figure 5 As shown, the movement of the upper drawing die 1 is controlled by the central control system. The central control system collects the position information of the battery box sheet and sets the parting line on the simulated battery box sheet. The parting line is used to divide the digital model into two parts. The parting line is the position of the punch of the lower drawing die 2, and the parting line is the position of the pressure ring 8. The central control system detects the position information of the battery box sheet. The lower drawing die 2 is set with bottom mark and ejector pin position. The bottom mark is used to check whether the upper drawing die 1 has reached the bottom at the end of the movement. The ejector pin position is used to mark the position of the ejector pin of the machine and is used to transmit the force.

[0053] In the drawing process, the battery box sheet undergoes deep drawing deformation through the closing process of the upper drawing die 1 and the lower drawing die 2, ultimately presenting the shape of the punch product. Due to the risk of cracking in some areas of the part formed in one step, the shape of these areas is gradually flattened and re-formed in subsequent forming processes. The design of the drawing process has two characteristics: First, it adopts a semi-opening 10 drawing, which greatly improves the utilization rate. In the drawing process, the feeding direction of the battery box sheet is controlled on the side of the upper and lower drawing dies, greatly reducing the internal stress on the side of the opening 10. The stress released during subsequent trimming is small, reducing the springback caused by the stress released during trimming. Second, it uses a double pressure plate, namely an upper pressure plate 4 and a lower pressure plate 14, to create a double drawing effect. The upper pressure plate 4 can move up and down, and the pressure of the pressure plate is provided by a nitrogen spring. After the upper drawing die 1 and the lower drawing die 2 are closed, they need to be separated, and the nitrogen spring will lift the upper pressure plate 4.

[0054] like Figure 7-11 As shown, the forming process is as follows: the battery box sheet is placed between the upper forming die 11 and the lower forming die 12, the upper forming die 11 moves towards the battery box sheet and the lower forming die 12, and the upper forming die 11 stamps the battery box sheet to complete the forming process.

[0055] The upper forming die 11 is configured as a concave die, and the lower forming die 12 is configured as a convex die. The upper forming die 11 is provided with an upper pressure plate 4 mounted by an elastic device, and the lower forming die 12 is provided with a lower pressure plate 14 mounted by an elastic device. When the upper forming die 11 moves downward and contacts the battery box material, the upper pressure plate 4 presses on the battery box material and stops moving. The upper forming die 11 continues to move, while the lower forming die 12 remains stationary. The lower pressure plate 14 moves downward under the pressure of the upper forming die 11. The battery box material is formed by the concave die and the convex die on the lower forming die 12.

[0056] The forming process uses double upper pressure plates 4. First, the battery box sheet material completed in the drawing process is placed on the forming lower die 12. The upper pressure plate 4 and the forming lower die 12 close first to ensure the flatness of the surface. Then, it continues to move downward until the upper pressure plate 4 and the forming lower die 12 are completely closed. Finally, the forming upper die 11 and the forming lower die 12 are completely closed. After the forming process is completed, the battery box sheet material produced includes the shape of the product, such as... Figure 12 As shown.

[0057] When designing the surfaces of the upper drawing die 1 and the lower drawing die 2, the local radius area 15 is enlarged as follows: Figure 9 As shown, the concave R-angle at the gradually diminishing sidewall of the product is enlarged, making the shape more rounded, reducing the principal stress it receives during the drawing process, and reducing the risk of cracking. In addition, the blank holder surface is 3mm higher than flange 16, preserving a part of the area to be formed and drawn properly in the forming process. This invention adopts a two-process forming process of drawing and forming, which can control the thinning rate, reduce the risk of cracking, make the drawing more complete, and make the forming more stable, ensuring the flatness of flange 16 and controlling the risk of wrinkling.

[0058] Trimming and punching process: This includes a first trimming and punching process and a second trimming and punching process. The trimming and punching of the battery box material is achieved by using two trimming and punching processes.

[0059] like Figure 12-14 As shown, the first trimming and punching process: the battery box plate is placed between the first trimming and punching upper die 17 and the first trimming and punching lower die 18. The first trimming and punching upper die 17 moves towards the battery box plate and the first trimming and punching lower die 18. The first trimming and punching upper die 17 punches the battery box plate to complete the first trimming and punching process.

[0060] The first trimming and punching upper die 17 is provided with a first upper die cutter block 19 and a first punching punch 20. While the first trimming and punching upper die 17 drives the first upper die cutter block 19 to trim the battery box sheet, the first punching punch 20 on the first trimming and punching lower die 18 punches the battery box sheet. The first trimming and punching lower die 18 is provided with a first trimming unloading hole 21 and a first punching unloading hole 22. The first trimming unloading hole 21 is located directly below the first upper die cutter block 19, and the first punching unloading hole 22 is located directly below the first punching punch 20.

[0061] A waste collection groove is provided below the first trimming unloading hole 21 and the first punching unloading hole 22. The first punching punch 20 moves downward to punch the battery box plate for the first time. The waste generated by the first punching enters the waste collection groove through the first punching unloading hole 22.

[0062] After the upper pressure plate 4 on the first trimming and punching upper die 17 closes with the first trimming and punching lower die 18, the upper die cutter block on the first trimming and punching upper die 17 travels a certain distance and trims the waste material. The trimming lines and punching lines of the battery box sheet are marked by the central control system to determine the waste area. The first trimming and punching lower die 18 is equipped with positioning pins to fix the battery box sheet and prevent it from slipping when placed on the first trimming and punching lower die 18. The state of the battery box sheet after the first trimming and punching process is as follows. Figure 14 As shown, the trimming ensures that the waste material size is less than 550mm and that the trimming range is symmetrical.

[0063] like Figure 15-17 As shown, the second trimming and punching process: the battery box plate is placed between the second trimming and punching upper die 25 and the second trimming and punching lower die 26. The second trimming and punching upper die 25 moves towards the battery box plate and the second trimming and punching lower die 26. The second trimming and punching upper die 25 punches the battery box plate to complete the second trimming and punching process.

[0064] The second trimming and punching upper die 25 is provided with a second upper die cutter block 27 and a second punching punch 28. While the second trimming and punching upper die 25 drives the second upper die cutter block 27 to trim the battery box sheet, the second punching punch 28 on the second trimming and punching lower die 26 punches the battery box sheet. The second trimming and punching lower die 26 is provided with a second trimming unloading hole 29 and a second punching unloading hole 30. The second trimming unloading hole 29 is located directly below the second upper die cutter block 27, and the second punching unloading hole 30 is located directly below the second punching punch 28.

[0065] A waste collection groove is provided below the second trimming unloading hole 29 and the second punching unloading hole 30. The second punching punch 28 moves downward to punch the battery box plate for the second time. The waste generated by the second punching enters the waste collection groove through the second punching unloading hole 30.

[0066] After the upper pressure plate 4 on the second trimming and punching upper die 25 closes with the second trimming and punching lower die 26, the upper die cutter block on the second trimming and punching upper die 25 travels a certain distance and trims the waste material. The trimming lines and punching lines of the battery box sheet are marked by the central control system to determine the waste area. The second trimming and punching lower die 26 is equipped with positioning pins to fix the battery box sheet and prevent it from slipping when placed on the second trimming and punching lower die 26. The state of the battery box sheet after the second trimming and punching process is as follows. Figure 17 As shown, the trimming ensures that the waste material size is less than 550mm and that the trimming range is symmetrical.

[0067] The first and second trimming positions are staggered to complete the trimming process of the battery box plate. The first and second punching respectively punch out all the functional holes of the battery box on the battery box plate.

[0068] like Figure 18-20 As shown, the forming process involves placing the battery box sheet between the upper forming die 32 and the lower forming die 33. The upper forming die 32 moves towards the battery box sheet and the lower forming die 33, and the upper forming die 32 stamps the battery box sheet to complete the forming process. The state of the battery box sheet after the forming process is as follows. Figure 20 As shown.

[0069] The upper forming mold 32 is equipped with an upper pressure plate 4 and a forming cutter block 34. After the upper pressure plate 4 closes with the lower forming mold 33, the forming cutter block 34 finally closes on the battery box plate to press out a 0.2mm long strip-shaped indentation and a flange 16 around the forming perimeter. The purpose of forming the flange 16 is to make the flange 16 more stable.

[0070] It should be understood that the term "and / or" in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. A and B can be singular or plural. Additionally, the character " / " in this article generally indicates an "or" relationship between the preceding and following related objects, but it can also represent an "and / or" relationship. Please refer to the context for a more accurate understanding.

[0071] In this invention, "at least one" means one or more, and "more than one" means two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of a single item or a plurality of items. For example, at least one of a, b, or c can represent: a, b, c, ab, ac, bc, or abc, where a, b, and c can be a single item or multiple items.

[0072] It should be understood that, in various embodiments of the present invention, the order of the above-mentioned process numbers does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0073] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A battery case production process, characterized by, The battery box production process comprises the following steps in sequence: The drawing process is completed by pressing of the drawing upper die and the drawing lower die, the drawing upper die is provided with an upper pressing plate mounted by an elastic device, the drawing lower die is provided with a pressing ring mounted by an elastic device, the drawing upper die and the drawing lower die are provided with an opening when closed, the drawing upper die moves towards the battery box blank and the drawing lower die, the upper pressing plate is firstly closed with the drawing lower die, and then the pressing ring is closed with the drawing upper die, so that the battery box blank generates a drawing rib in the process; The forming process is completed by pressing of the forming upper die and the forming lower die, when the forming upper die moves downwards and contacts the battery box blank, the upper pressing plate stops moving after being pressed on the battery box blank, the forming upper die continues to move, while the forming lower die remains different, the lower pressing plate moves downwards under the pressure of the forming upper die, and the battery box blank is formed by the concave die on the forming lower die and the convex die on the forming lower die; The partial R corner area of the drawing upper die and the drawing lower die is enlarged, and the pressing surface is 3mm higher than the flange, and a part of the area is shaped and drawn in place in the forming process; The trimming and punching process comprises a first trimming and punching process and a second trimming and punching process, and the trimming and punching of the battery box blank is realized by two trimming and punching processes; The shaping process is completed by stamping of the shaping upper die on the battery box blank and the shaping lower die.

2. The battery case production process according to claim 1, wherein In the drawing process, the feeding direction of the battery box blank is on the side surface of the drawing upper die and the drawing lower die.

3. The battery case production process according to claim 1, wherein The elastic device adopts a nitrogen spring.

4. The battery case production process according to claim 1, wherein A drawing rib is added on the battery box blank in the drawing process.

5. The battery case production process according to claim 1, wherein The first trimming and punching lower die is provided with a first trimming discharge hole and a first punching discharge hole, the second trimming and punching lower die is provided with a second trimming discharge hole and a second punching discharge hole, and a waste collecting groove is arranged below the first trimming discharge hole, the first punching discharge hole, the second trimming discharge hole and the second punching discharge hole.

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