Drawing process for 46120 cylindrical battery shell

Abstract

The application discloses a 46120 type cylindrical battery shell drawing process, which comprises the following steps: drawing a blank with a diameter of 145mm-150mm and a thickness of 0.6mm±0.06mm, the drawing coefficient ranges from 0.54 to 0.56, the first concave die entering mode radius ranges from 7mm to 10mm, the first convex die radius ranges from 7mm to 10mm, the edge pressing mode is flat edge pressing, the edge pressing force ranges from 2.5T to 3.0T, and a hollow cylindrical first semi-finished product is formed after drawing. The 46120 type cylindrical battery shell drawing process can realize the forming of the cylindrical battery shell through four drawing processes, and greatly improves the drawing efficiency.

Description

Technical Field

[0001] This application relates to a deep drawing process for battery casings, and more particularly to a deep drawing process for a 46120 type cylindrical battery casing. Background Technology

[0002] In related technologies, cylindrical batteries are widely used in industries such as new energy vehicles and power tools, serving as the basic unit of a battery system. The 46120 battery is a cylindrical battery casing with a diameter of 46mm and a height of 120mm. Currently, it is typically produced by drawing steel sheet through 8-11 continuous drawing stations using a die to obtain the cylindrical battery casing. However, the more drawing stations there are, the more dies are needed, and the more supporting equipment is required, leading to increased production costs. Furthermore, more dies result in increased time spent on die assembly, repair, and adjustment, thus reducing production efficiency. Summary of the Invention

[0003] This invention aims to at least solve one of the technical problems existing in the prior art. To this end, this application proposes a deep drawing process for a 46120 cylindrical battery casing, which can achieve the forming of a cylindrical battery casing through four deep drawing processes, greatly improving the deep drawing efficiency.

[0004] The deep drawing process for the 46120 cylindrical battery casing according to an embodiment of the present invention includes the following steps:

[0005] For blanks with a diameter of 145mm to 150mm and a thickness of 0.6mm ± 0.06mm, deep drawing is performed. The deep drawing coefficient ranges from 0.54 to 0.56. The radius of the first die entry fillet ranges from 7 to 10mm. The radius of the first punch fillet ranges from 7 to 10mm. The blank holder method is flat blank holder. The blank holder force ranges from 2.5T to 3.0T. After deep drawing, the first semi-finished product is formed.

[0006] The first semi-finished product is deep-drawn with a deep-drawing coefficient ranging from 0.76 to 0.78. The radius of the second die entry fillet is ranging from 5 to 7 mm, and the radius of the second punch fillet is also ranging from 5 to 7 mm. The feed point of the second die is a first conical opening with a cone angle of 90° to 120°, so that the entry angle of the first semi-finished product is 45° to 60°. The blank holder of the first semi-finished product is a conical blank holder to match the first conical opening, and the blank holder force ranges from 1T to 1.5T. After deep drawing, the second semi-finished product is formed.

[0007] The second semi-finished product is deep-drawn with a deep-drawing coefficient ranging from 0.8 to 0.82. The radius of the third die entry fillet is ranging from 3 to 5 mm, and the radius of the third punch fillet is ranging from 3 to 5 mm. The feed point of the third die is a second conical opening with a cone angle of 20° to 40°, so that the entry angle of the second semi-finished product is 10° to 20°. After deep drawing, the third semi-finished product is formed.

[0008] The third semi-finished product is deep-drawn and thinned, with a deep-drawing coefficient ranging from 0.87 to 0.91. The radius of the fourth die entry fillet is ranging from 3 to 5 mm. The feed point of the fourth die is a third conical opening with a cone angle of 30° to 60°, so that the entry angle of the third semi-finished product is 15° to 30°. The fillet radius of the fourth die forming part is 80% to 90% of the outer fillet radius required for the finished battery case. The fillet radius of the fourth punch is 90% to 100% of the inner fillet radius required for the finished battery case. After deep drawing, the fourth semi-finished product is formed.

[0009] A perforation is machined into the closed end face of the fourth semi-finished product to form the finished battery casing.

[0010] The deep drawing process for the 46120 cylindrical battery casing according to embodiments of the present invention has at least the following beneficial effects: the deep drawing of the blank can be completed by only four deep drawing processes; specifically, the first deep drawing is performed on a blank with a diameter ranging from 145mm to 150mm and a thickness of 0.6mm ± 0.06mm, with a deep drawing coefficient ranging from 0.54 to 0.56. The first die has a fillet at the blank inlet, which is called the first die entry fillet, with a radius ranging from 7 to 10mm. The first punch also has a fillet at the end that abuts against the blank, with a radius ranging from 7 to 10mm. The blank holder is a flat blank holder, with a blank holder force ranging from 2.5T to 3.0T, that is, the blank holder force is between the blank holder and the end face of the first die. The annular portion of the blank is gradually drawn into the gap between the punch and die while being pressed, and the contact surface between the pressing ring and the annular portion of the blank is horizontal, thus achieving horizontal pressing to prevent wrinkling of the drawn part. After the first deep drawing, a first semi-finished product is formed. Subsequently, the first semi-finished product undergoes a second deep drawing process. The drawing coefficient of the second deep drawing is 0.76 to 0.78. The rounded corner of the second die at the feed port of the first semi-finished product is called the second die entry rounded corner. The radius of the second die entry rounded corner is in the range of 5 to 7 mm. The radius of the second punch rounded corner is also in the range of 5 to 7 mm. A first conical opening is provided at the feed port of the second die, which connects to the second die entry rounded corner. The diameter of the first conical opening extends from the opening to near the second die entry rounded corner. The cone angle of the first conical opening gradually decreases, ranging from 90° to 120°, thus making the die entry angle α of the first semi-finished product range from 45° to 60°. This means the angle α between the generatrix of the cone containing the first conical opening and the vertical direction ranges from 45° to 60°. The blank holder for the first semi-finished product is a conical blank holder, with the blank holder's angle matching the first conical opening's slope, thereby achieving blank holder pressure on the drawn part and preventing wrinkling. The blank holder force ranges from 1T to 1.5T. After the second drawing process, the second semi-finished product is formed. Next, the second semi-finished product undergoes a third drawing process. The drawing coefficient for the third drawing process is 0.87 to 0.91. The third drawing process uses a third die and a third punch. The third die is located at the feed inlet of the second semi-finished product. Some rounded corners are the entry rounded corners of the third die cavity, with a radius ranging from 3 to 5 mm. The radius of the third punch rounded corner also ranges from 3 to 5 mm. A second conical opening is provided at the feed inlet of the third die cavity, connecting to the entry rounded corner of the third die cavity. The diameter of the second conical opening gradually decreases from the opening to near the entry rounded corner of the third die cavity, and the cone angle of the second conical opening is 20° to 40°. This results in the entry angle β of the second semi-finished product ranging from 10° to 20°, that is, the angle β between the generatrix of the cone containing the second conical opening and the vertical direction ranges from 10° to 20°. After the third deep drawing, the third semi-finished product is formed. Then, the third semi-finished product undergoes a fourth deep drawing and thinning process, with the deep drawing coefficient in the fourth deep drawing process ranging from 0.87~0.91, the fourth die has a fillet at the feed inlet of the third semi-finished product, which is called the fourth die entry fillet. The radius of the fourth die entry fillet ranges from 3 to 5 mm. The feed inlet of the fourth die has a third conical opening, which connects to the fourth die entry fillet. The diameter of the third conical opening gradually decreases from the opening to near the fourth die entry fillet. The cone angle of the third conical opening is 30°~60°, so that the die entry angle δ of the third semi-finished product ranges from 15°~30°. That is, the angle δ between the generatrix of the cone containing the third conical opening and the vertical direction ranges from 15°~30°. Moreover, in the fourth drawing process, the fourth die has a fourth die forming fillet for forming the outer fillet of the drawn part. The fourth punch is equipped with a fourth punch fillet for forming the inner fillet of the drawn part. Since the fourth drawing is the last drawing, the gravity of the bottom of the drawn part and the expansion of the drawn part after drawing need to be considered. Therefore, the radius of the fourth die forming fillet is 80% to 90% of the outer fillet radius required by the finished battery case, and the radius of the fourth punch fillet is 90% to 100% of the inner fillet radius required by the finished battery case. During the fourth drawing process, the gap between the fourth punch and the fourth die is smaller than the thickness of the third semi-finished product. That is, the drawn part is thinned at the same time as the fourth drawing. After the fourth drawing, the fourth semi-finished product is formed. Then, the closed end face of the fourth semi-finished product is machined to form a perforation, thereby forming the finished battery case. The above four deep-drawing processes enable the forming of the 46120 cylindrical battery casing. The resulting casing exhibits uniform wall and base thickness, is free of wrinkles or cracks, and has good flatness. This process significantly reduces the number of processing steps and deep-drawing stations, lowering the costs of molds, machines, and automated machinery. It also reduces the time spent on mold assembly, repair, and adjustment, ultimately improving production efficiency.

[0011] According to some embodiments of the present invention, the method includes the following steps: stamping and blanking a sheet metal with a thickness of 0.6 mm ± 0.06 mm to form a blank with a diameter of 145 mm to 150 mm.

[0012] According to some embodiments of the present invention, the following step is included: removing burrs from the end of the fourth semi-finished product away from the closed end.

[0013] According to some embodiments of the present invention, the burrs at the end of the fourth semi-finished product furthest from the closed end are removed by rotary cutting.

[0014] According to some embodiments of the present invention, the following steps are included: before deep drawing, deep drawing oil is sprayed onto the blank, the first die, the second die, the third die, and the fourth die.

[0015] According to some embodiments of the present invention, the following steps are included: spraying oil onto a punch used for stamping the sheet metal.

[0016] According to some embodiments of the present invention, the following steps are included: cleaning oil stains on the finished battery casing.

[0017] According to some embodiments of the present invention, cleaning the oil stains on the finished battery casing includes the following steps: placing the finished battery casing into an ultrasonic cleaner for cleaning.

[0018] According to some embodiments of the present invention, cleaning the oil stains on the finished battery casing includes the following steps: drying the cleaned finished battery casing.

[0019] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0021] Figure 1 This is a flowchart illustrating the process from raw material processing to finished battery casing in an embodiment of the present invention;

[0022] Figure 2 This is a cross-sectional view of the drawn part in the first drawing process in an embodiment of the present invention;

[0023] Figure 3 This is a cross-sectional view of the drawn part in the second drawing process in an embodiment of the present invention;

[0024] Figure 4 This is a cross-sectional view of the drawn part in the third drawing process in an embodiment of the present invention;

[0025] Figure 5 This is a cross-sectional view of the drawn part in the fourth drawing process in an embodiment of the present invention;

[0026] Figure 6 This is a schematic diagram of the finished battery casing in an embodiment of the present invention.

[0027] Figure label:

[0028] 110. First die cavity; 111. First die cavity entry radius; 120. First punch; 121. First punch radius; 130. Pressure ring;

[0029] 210. Second die cavity; 211. Second die cavity entry radius; 212. First tapered opening; 220. Second punch; 221. Second punch radius; 230. Blank holder;

[0030] 310. Third die cavity; 311. Third die cavity entry radius; 312. Second conical opening; 320. Third punch; 321. Third punch radius;

[0031] 410. Fourth die cavity; 411. Fourth die cavity entry fillet; 412. Third conical opening; 413. Fourth die cavity forming fillet; 420. Fourth punch; 421. Fourth punch fillet;

[0032] 500, Deep-drawn parts; 600, Finished battery casings; 610, Perforation. Detailed Implementation

[0033] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0034] In the description of this application, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0035] In the description of this application, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0036] In the description of this application, unless otherwise expressly defined, terms such as "setup," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this application in conjunction with the specific content of the technical solution.

[0037] In the description of this application, the terms "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0038] The following is for reference. Figures 1 to 6 The deep drawing process of the 46120 cylindrical battery case according to an embodiment of the present invention is described.

[0039] like Figures 1 to 6 As shown, the deep drawing process for the 46120 type cylindrical battery casing according to an embodiment of the present invention includes the following steps:

[0040] S100: Deep drawing of blanks with a diameter of 145mm to 150mm and a thickness of 0.6mm ± 0.06mm, with a deep drawing coefficient ranging from 0.54 to 0.56, a first die entry radius of 111 ranging from 7 to 10mm, a first punch radius of 121 ranging from 7 to 10mm, a flat blanking method, and a blanking force ranging from 2.5T to 3.0T, resulting in a hollow cylindrical first semi-finished product after deep drawing;

[0041] S200: The first semi-finished product is deep-drawn, with a deep-drawing coefficient ranging from 0.76 to 0.78. The radius of the second die entry fillet 211 ranges from 5 to 7 mm, and the radius of the second punch fillet 221 ranges from 5 to 7 mm. The feed point of the second die 210 is a first conical opening 212, with a cone angle of 90° to 120°, so that the entry angle of the first semi-finished product is 45° to 60°. The blank holder method for the first semi-finished product is a conical blank holder to match the first conical opening 212. The blank holder force ranges from 1T to 1.5T. After deep drawing, the second semi-finished product is formed.

[0042] S300: The second semi-finished product is deep-drawn, with a deep-drawing coefficient ranging from 0.8 to 0.82. The radius of the third die entry fillet 311 ranges from 3 to 5 mm, and the radius of the third punch fillet 321 ranges from 3 to 5 mm. The feed point of the third die 310 is a second conical opening 312, with a cone angle of 20° to 40°, so that the entry angle of the second semi-finished product is 10° to 20°. After deep drawing, the third semi-finished product is formed.

[0043] S400: The third semi-finished product is deep-drawn and thinned, with a deep-drawing coefficient ranging from 0.87 to 0.91. The radius of the fourth die entry fillet 411 ranges from 3 to 5 mm. The feed point of the fourth die 410 is the third conical opening 412, with a cone angle of 30° to 60°, so that the entry angle of the third semi-finished product is 15° to 30°. The fillet radius of the forming part of the fourth die 410 is 80% to 90% of the outer fillet radius required for the finished battery case 600. The fillet radius of the fourth punch 420 is 90% to 100% of the inner fillet radius required for the finished battery case 600. After deep drawing, the fourth semi-finished product is formed.

[0044] S500: A perforation 610 is machined into the closed end face of the fourth semi-finished product to form the finished battery case 600.

[0045] like Figures 1 to 6As shown, in this embodiment, only four drawing processes are required to complete the drawing of the blank. Specifically, the first drawing process involves drawing a blank with a diameter ranging from 145mm to 150mm and a thickness of 0.6mm ± 0.06mm, with a drawing coefficient ranging from 0.54 to 0.56. The first die 110 has a fillet at the blank inlet, which is called the first die entry fillet 111, and the radius of the first die entry fillet 111 ranges from 7 to 10mm. The first punch 120 also has a fillet at the end that abuts against the blank, and the radius of the first punch fillet 121 is... The blanking thickness ranges from 7 to 10 mm, the blanking method is flat blanking, and the blanking force ranges from 2.5T to 3.0T. That is, the annular portion of the blank between the blanking ring 130 and the end face of the first die 110 is gradually drawn into the gap between the punch and die while being blanked. Furthermore, the contact surface between the blanking ring 130 and the annular portion of the blank is horizontal, thus achieving horizontal blanking to prevent wrinkling of the drawn part 500. After the first deep drawing, a first semi-finished product is formed. Subsequently, a second deep drawing process is performed on the first semi-finished product. The drawing coefficient of the second deep drawing is 0.76 to 0.78. The second die... The fillet 210 at the inlet of the first semi-finished product is the second die inlet fillet 211, with a radius of 5-7 mm. The radius of the second punch fillet 221 is also 5-7 mm. A first tapered opening 212 is provided at the inlet of the second die 210, connecting to the second die inlet fillet 211. The diameter of the first tapered opening 212 gradually decreases from its opening towards the second die inlet fillet 211, and the cone angle of the first tapered opening 212 is 90°-120°, thus ensuring the smooth entry of the first semi-finished product. The die angle α ranges from 45° to 60°, that is, the angle α between the generatrix of the cone containing the first conical opening 212 and the vertical direction ranges from 45° to 60°. The pressing method for the first semi-finished product is a conical pressing. The pressing part 230 is adapted to the slope of the first conical opening 212, thereby realizing the pressing of the drawn part 500 and preventing the drawn part 500 from wrinkling. The pressing force ranges from 1T to 1.5T. After the second drawing, the second semi-finished product is formed. Then, the second semi-finished product undergoes a third drawing process. The drawing coefficient of the third drawing process is 0.87 to 0.91. The third deep drawing process uses a third die 310 and a third punch 320 for deep drawing. The third die 310 has a fillet at the inlet of the second semi-finished product, which is called the third die entry fillet 311. The radius of the third die entry fillet 311 is in the range of 3-5 mm. The radius of the third punch fillet 321 is also in the range of 3-5 mm. A second conical opening 312 is provided at the inlet of the third die 310. The second conical opening 312 connects to the third die entry fillet 311, and the diameter of the second conical opening 312 is... The radius gradually decreases from the opening to near the third die entry fillet 311. The cone angle of the second conical opening 312 is 20° to 40°, so that the die entry angle β of the second semi-finished product is in the range of 10° to 20°. That is, the angle β between the generatrix of the cone containing the second conical opening 312 and the vertical direction is in the range of 10° to 20°. After the third deep drawing, the third semi-finished product is formed. Then, the third semi-finished product is subjected to a fourth deep drawing and thinning. The deep drawing coefficient in the fourth deep drawing process is in the range of 0.87 to 0.91. The fourth die 410 has a fillet at the feed inlet of the third semi-finished product, which is called the fourth die entry fillet 411. The radius of the fourth die entry fillet 411 is 3-5 mm. The feed inlet of the fourth die 410 has a third conical opening 412, which connects to the fourth die entry fillet 411. The diameter of the third conical opening 412 gradually decreases from the opening to near the fourth die entry fillet 411. The cone angle of the third conical opening 412 is 30°-60°, so that the die entry angle δ of the third semi-finished product is 15°-30°. That is, the angle δ between the generatrix of the cone containing the third conical opening 412 and the vertical direction is 15°-30°. In the fourth drawing process, the fourth die 410 has a fourth die forming fillet 413 for forming the outer fillet of the drawn part 500. The punch 420 is provided with a fourth punch fillet 421 for forming the inner fillet of the drawn part 500. Since the fourth drawing is the last drawing, it is necessary to consider the gravity of the bottom of the drawn part 500 after drawing and the expansion of the drawn part 500. Therefore, the radius of the fourth die forming fillet 413 is 80% to 90% of the outer fillet radius required by the finished battery case 600, and the radius of the fourth punch fillet 421 is 90% to 100% of the inner fillet radius required by the finished battery case 600. During the fourth drawing process, the gap between the fourth punch 420 and the fourth die 410 is less than the thickness of the third semi-finished product. That is, the drawn part 500 is thinned at the same time as the fourth drawing. After the fourth drawing, the fourth semi-finished product is formed. Then, the closed end face of the fourth semi-finished product is machined to form a through hole 610, thereby forming the finished battery case 600. The above four deep-drawing processes enable the forming of the 46120 cylindrical battery casing. The resulting casing exhibits uniform wall and base thickness, is free of wrinkles or cracks, and has good flatness. This process significantly reduces the number of processing steps and deep-drawing stations, lowering the costs of molds, machines, and automated machinery. It also reduces the time spent on mold assembly, repair, and adjustment, ultimately improving production efficiency.

[0046] In the deep drawing process from the blank to the finished battery casing 600, the first semi-finished product, the second semi-finished product, the third semi-finished product, and the fourth semi-finished product can all be called the deep-drawn part 500. The blank is made of galvanized steel sheet or nickel-plated steel sheet.

[0047] Example 1:

[0048] For a blank with a diameter of 147mm±1mm and a thickness of 0.6mm±0.06mm, the drawing coefficient is 0.56, the radius of the first die entry radius is 10mm, the radius of the first punch radius is 10mm, the blank holder method is flat blank holder, the blank holder force is 2.5T, and after drawing, a hollow cylindrical first semi-finished product is formed;

[0049] The first semi-finished product is deep-drawn with a deep-drawing coefficient of 0.77. The radius of the second die entry fillet 211 is 7mm, the radius of the second punch fillet 221 is 7mm, the feed point of the second die 210 is a first conical opening 212, and the cone angle of the first conical opening 212 is 90° so that the entry angle of the first semi-finished product is 45°. The blank holder method of the first semi-finished product is a conical blank holder to match the first conical opening 212. The blank holder force is 1T. After deep drawing, the second semi-finished product is formed.

[0050] The second semi-finished product is deep-drawn with a deep-drawing coefficient of 0.82. The radius of the third die cavity fillet 311 is 5mm, the radius of the third punch fillet 321 is 5mm, and the feed point of the third die cavity 310 is the second conical opening 312 with a cone angle of 30°, so that the die entry angle of the second semi-finished product is 15°, and the third semi-finished product is formed after deep drawing.

[0051] The third semi-finished product is deep-drawn and thinned with a deep-drawing coefficient of 0.88. The radius of the fourth die cavity fillet 411 is 5mm. The feed point of the fourth die cavity 410 is the third conical opening 412 with a cone angle of 60°, so that the die entry angle of the third semi-finished product is 30°. The outer fillet radius required for the battery case finished product 600 is 1.5mm. The fillet radius of the forming part of the fourth die cavity 410 is 90% of the outer fillet radius required for the battery case finished product 600, that is, the fillet radius of the forming part of the fourth die cavity 410 is 1.35mm. The inner fillet radius required for the battery case finished product 600 is 1mm. The radius of the fourth punch fillet 421 is 100% of the inner fillet radius required for the battery case finished product 600, that is, the radius of the fourth punch fillet 421 is 1mm. After deep drawing, the fourth semi-finished product is formed.

[0052] A perforation 610 is machined into the closed end face of the fourth semi-finished product to form the finished battery casing 600.

[0053] Example 2:

[0054] For a blank with a diameter of 150mm±1mm and a thickness of 0.6mm±0.06mm, the drawing coefficient is 0.54, the radius of the first die entry radius is 7mm, the radius of the first punch radius is 7mm, the blank holder method is flat blank holder, the blank holder force is 3T, and after drawing, a hollow cylindrical first semi-finished product is formed.

[0055] The first semi-finished product is deep-drawn with a deep-drawing coefficient of 0.76. The radius of the second die entry fillet 211 is 5mm, the radius of the second punch fillet 221 is 5mm, the feed point of the second die 210 is a first conical opening 212, and the cone angle of the first conical opening 212 is 120° so that the die entry angle of the first semi-finished product is 60°. The blank holder method of the first semi-finished product is a conical blank holder to match the first conical opening 212. The blank holder force is 1.5T. After deep drawing, the second semi-finished product is formed.

[0056] The second semi-finished product is deep-drawn with a deep-drawing coefficient of 0.8. The radius of the third die cavity fillet 311 is 4mm, the radius of the third punch fillet 321 is 4mm, and the feed point of the third die cavity 310 is the second conical opening 312 with a cone angle of 40°, so that the entry angle of the second semi-finished product is 20°. After deep drawing, the third semi-finished product is formed.

[0057] The third semi-finished product is deep-drawn and thinned with a deep-drawing coefficient of 0.91. The radius of the fourth die cavity fillet 411 is 3mm. The feed point of the fourth die cavity 410 is the third conical opening 412 with a cone angle of 30°, so that the die entry angle of the third semi-finished product is 15°. The outer fillet radius required for the battery case finished product 600 is 1.5mm. The fillet radius of the forming part of the fourth die cavity 410 is 80% of the outer fillet radius required for the battery case finished product 600, that is, the fillet radius of the forming part of the fourth die cavity 410 is 1.2mm. The inner fillet radius required for the battery case finished product 600 is 1mm. The radius of the fourth punch fillet 421 is 90% of the inner fillet radius required for the battery case finished product 600, that is, the radius of the fourth punch fillet 421 is 0.9mm. After deep drawing, the fourth semi-finished product is formed.

[0058] A perforation 610 is machined into the closed end face of the fourth semi-finished product to form the finished battery casing 600.

[0059] It should be understood that as the deep drawing process progresses, the yield strength of the deep-drawn part 500 increases with the increase of its hardness. Therefore, in the third and fourth deep drawing processes, edge pressing is not required, and the deep-drawn part 500 will not wrinkle. At the same time, the cost of edge pressing dies is saved, and the time spent on die assembly, repair and adjustment is saved, thus improving production efficiency.

[0060] It should be understood that, in this embodiment, during the fourth deep drawing and thinning process, the gap between the fourth punch 420 and the fourth die 410 is 0.45mm to 0.5mm, so that after the fourth deep drawing and thinning, the sidewall thickness of the deep-drawn part 500 is 0.4mm to 0.55mm.

[0061] It also includes the following steps:

[0062] S600: Stamping and blanking of sheet metal with a thickness of 0.6mm±0.06mm to form a blank with a diameter of 145mm~150mm.

[0063] Understandably, the sheet metal with a thickness of 0.6±0.06mm is first stamped to obtain a blank with a diameter of 145mm to 150mm, so that the subsequent deep drawing process can be carried out.

[0064] It also includes the following steps:

[0065] S700: Removes burrs from the end of the fourth semi-finished product furthest from the closed end.

[0066] It is understandable that after the fourth semi-finished product is formed, the end of the fourth semi-finished product that is far from the closed end may not be flat. Therefore, it is necessary to deburr it to make the end of the fourth semi-finished product that is far from the closed end flat.

[0067] It is understandable that the method for removing burrs from the end of the fourth semi-finished product away from the closed end is rotary cutting. For example, as shown in Figures 1-2, in this embodiment, the method for removing burrs from the end of the fourth semi-finished product away from the closed end is rotary cutting, that is, the cylindrical fourth semi-finished product is rotated around a fixed axis, and the cutting edge moves in a feed motion parallel to the axis of the fourth semi-finished product, cutting the end of the fourth semi-finished product away from the closed end radially.

[0068] It should be understood that, in addition to the rotary cutting method mentioned above, burrs can also be removed from the end of the fourth semi-finished product that is far from the closed end by turning or sawing.

[0069] It also includes the following steps:

[0070] S800: Before deep drawing, spray deep drawing oil on the blank, first die 110, second die 210, third die 310 and fourth die.

[0071] Understandably, in this embodiment, before deep drawing, deep drawing oil is sprayed onto the blank, the first die 110, the second die 210, the third die 310, and the fourth die 410. The deep drawing oil provides good lubrication during the deep drawing process, reducing friction between the drawn part 500 and the corresponding dies in the deep drawing process. This not only improves the quality of the drawn part 500 but also extends the service life of the dies during the deep drawing process. The dies here include the first die 110, the first punch 120, the second die 210, the second punch 220, the third die 310, the third punch 320, the fourth die 410, and the fourth punch 420.

[0072] It also includes the following steps:

[0073] S900: Oil spraying for punches used in stamping sheet metal.

[0074] It is understandable that in this embodiment, the stamping of sheet metal is mainly achieved by the punch on the punch press. Spraying oil onto the punch can improve the quality of the blank and also increase the service life of the punch.

[0075] It also includes the following steps:

[0076] S1000: Cleans oil stains on finished battery casing 600.

[0077] It is understood that in this embodiment, the battery casing finished product 600 formed after deep drawing needs to be cleaned of oil stains in order to ensure the cleanliness of the battery casing finished product 600.

[0078] It should be understood that the oil stains on the finished battery casing 600 can be cleaned manually, or the oil removal process on the finished battery casing 600 can be achieved through automated equipment.

[0079] Cleaning oil stains from the finished battery casing 600 also includes the following steps:

[0080] S1100: Place the finished battery casing 600 into an ultrasonic cleaner for cleaning.

[0081] S1200: Dry the cleaned battery casing finished product 600.

[0082] It is understood that in this embodiment, the finished battery casing 600 is first placed in an ultrasonic cleaner for cleaning, and then the cleaned finished battery casing 600 is taken out and dried, thereby removing oil stains from the finished battery casing 600.

[0083] It should be understood that ultrasonic cleaners contain cleaning agents.

[0084] The embodiments of this application have been described in detail above with reference to the accompanying drawings. However, this application is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of this application. Furthermore, unless otherwise specified, the embodiments and features described in the embodiments of this application can be combined with each other.

Claims

1. 46120 type cylindrical battery casing deep drawing process, characterized in that, Includes the following steps: For blanks with a diameter of 145mm to 150mm and a thickness of 0.6mm ± 0.06mm, deep drawing is performed. The deep drawing coefficient ranges from 0.54 to 0.

56. The radius of the first die entry fillet ranges from 7 to 10mm. The radius of the first punch fillet ranges from 7 to 10mm. The blank holder method is flat blank holder. The blank holder force ranges from 2.5T to 3.0T. After deep drawing, the first semi-finished product is formed. The first semi-finished product is deep-drawn with a deep-drawing coefficient ranging from 0.76 to 0.

78. The radius of the second die entry fillet is ranging from 5 to 7 mm, and the radius of the second punch fillet is also ranging from 5 to 7 mm. The feed point of the second die is a first conical opening with a cone angle of 90° to 120°, so that the entry angle of the first semi-finished product is 45° to 60°. The blank holder of the first semi-finished product is a conical blank holder to match the first conical opening, and the blank holder force ranges from 1T to 1.5T. After deep drawing, the second semi-finished product is formed. The second semi-finished product is deep-drawn with a deep-drawing coefficient ranging from 0.8 to 0.

82. The radius of the third die entry fillet is ranging from 3 to 5 mm, and the radius of the third punch fillet is ranging from 3 to 5 mm. The feed point of the third die is a second conical opening with a cone angle of 20° to 40°, so that the entry angle of the second semi-finished product is 10° to 20°. After deep drawing, the third semi-finished product is formed. The third semi-finished product is deep-drawn and thinned, with a deep-drawing coefficient ranging from 0.87 to 0.

91. The radius of the fourth die entry fillet is ranging from 3 to 5 mm. The feed point of the fourth die is a third conical opening with a cone angle of 30° to 60°, so that the entry angle of the third semi-finished product is 15° to 30°. The fillet radius of the fourth die forming part is 80% to 90% of the outer fillet radius required for the finished battery case, and the fillet radius of the fourth punch is 90% to 100% of the inner fillet radius required for the finished battery case. After deep drawing, the fourth semi-finished product is formed. A perforation is machined into the closed end face of the fourth semi-finished product to form the finished battery casing.

2. The deep drawing process for the 46120 type cylindrical battery casing according to claim 1, characterized in that, Includes the following steps: A sheet metal with a thickness of 0.6mm ± 0.06mm is punched and blanked to form a blank with a diameter of 145mm to 150mm.

3. The deep drawing process for the 46120 type cylindrical battery casing according to claim 1, characterized in that, It also includes the following steps: Remove the burrs from the end of the fourth semi-finished product that is furthest from the closed end.

4. The deep drawing process for the 46120 type cylindrical battery casing according to claim 3, characterized in that, The method for removing burrs from the end of the fourth semi-finished product furthest from the closed end is rotary cutting.

5. The deep drawing process for the 46120 type cylindrical battery casing according to claim 1, characterized in that, Includes the following steps: Before deep drawing, deep drawing oil is sprayed onto the blank, the first die, the second die, the third die, and the fourth die.

6. The deep drawing process for the 46120 type cylindrical battery casing according to claim 2, characterized in that, Includes the following steps: Oil is sprayed onto the punch used for stamping the sheet metal.

7. The deep drawing process for the 46120 type cylindrical battery casing according to claim 5, characterized in that, Includes the following steps: Clean the oil stains on the finished battery casing.

8. The deep drawing process for the 46120 type cylindrical battery casing according to claim 7, characterized in that, Cleaning the oil stains on the finished battery casing includes the following steps: The finished battery casing is placed in an ultrasonic cleaner for cleaning.

9. The deep drawing process for the 46120 type cylindrical battery casing according to claim 8, characterized in that, Cleaning the oil stains on the finished battery casing includes the following steps: The cleaned battery casing is then dried.

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