Cold extrusion forming process for round aluminum shell with anti-explosion power battery of new energy automobile

Abstract

The invention relates to the field of cold extrusion forming, and discloses a cold extrusion forming process for a round aluminum shell with an anti-explosion power battery of a new energy automobile, which is characterized by comprising the following steps of: manufacturing a round aluminum blank: designing the size of the blank according to the aluminum shell of the power battery; the manufactured round aluminum blank is subjected to lubricating treatment, specifically, the manufactured aluminum blank is treated, a continuous casting and rolling process is adopted, a round or square blank formed through blanking is treated through a shot blasting process, the lubricating force of the blank before extrusion is increased, then the aluminum blank is subjected to stirring and smearing treatment through light zinc stearate powder through a round throwing cage, and the aluminum blank is subjected to heat treatment; a horizontal multi-connecting-rod toggle rod type cold extrusion press is used for cold extrusion forming, a lower die female die with a notch groove is placed into a female die base with the center automatically adjusted, and the circular aluminum shell with the anti-explosion power battery is formed through one-time cold extrusion. The cold-extruded aluminum shell is more compact in grain structure, the service life of the explosion-proof battery is prolonged, the cold-extruded aluminum shell with the explosion-proof battery is better in heat conductivity and heat stability, and heat dissipation of the battery is facilitated.

Description

Technical Field

[0001] The present invention relates to the field of cold extrusion forming, and in particular to a cold extrusion forming process for a round aluminum shell with an explosion-proof power battery for a new energy vehicle. Background Art

[0002] The core function of the circular explosion-proof aluminum battery casing for new energy vehicles is to prevent explosions through controlled pressure relief in the event of thermal runaway. While meeting the requirements of lightweight, high strength, and sealing, it represents a new, emission-free, environmentally friendly product for the energy industry. Currently, domestic companies employ three main traditional production methods. One involves separate stamping, followed by laser girth welding, and finally explosion-proof processing. This method suffers from a weak spot in the weld seam, resulting in low cost but limited performance, making it suitable for batteries with low energy density. The second method utilizes a spinning process, which involves hot spinning, followed by explosion-proof processing, and finally finishing. The key issue is that while there are no welds, the production cost is high. The third method utilizes a hot extrusion process, which involves high-temperature extrusion, cold rolling to size, and finally explosion-proof processing. This method suffers from coarse grains, making it more suitable for batteries used in low-end power tools.

[0003] Document CN 104096719 A discloses a cold extrusion die and forming method for a power battery aluminum shell. The die consists of an upper die and a lower die. The upper die includes an upper punch, an upper die holder, a spacer, a clamping sleeve, a clamping nut, and fixing bolts. The lower die includes a lower die, a spacer, a die holder, a die nut, multiple clamping blocks, and multiple bolts. This structure can cause the cold-extruded blank to crack during cold extrusion.

[0004] Therefore, a new technical solution is needed to solve the above technical problems. Summary of the Invention

[0005] In order to solve the above problems, the present invention discloses a cold extrusion forming process for a round aluminum shell with an explosion-proof power battery for new energy vehicles. The grain structure of the aluminum shell after cold extrusion is denser, which extends the service life of the explosion-proof battery. The cold-extruded aluminum shell with an explosion-proof battery has better thermal conductivity and thermal stability, which helps to dissipate heat from the battery and greatly improves safety.

[0006] The technical solution of the present invention is: a cold extrusion forming process for a round aluminum shell with an explosion-proof power battery for a new energy vehicle, characterized by comprising the following steps: Step 1: Make aluminum round billet: Design the billet size according to the shape, size, weight and performance parameter requirements of the power battery aluminum shell; Step 2: Lubricate the aluminum round billet: The aluminum billet is processed by continuous casting and rolling process. The round or square billet formed by blanking is subjected to shot blasting process to increase the lubrication of the billet before extrusion. A stirring device is used to stir and apply light zinc stearate powder on the aluminum billet. The light zinc stearate powder is exposed to the sun at 25°C for 3 hours before use. It is moisture-proof and humidity-proof. The dosage is 120g of light zinc stearate powder for every 100kg of billet. The application and stirring are carried out for 18-20 minutes. Step 3: Cold extrusion forming uses a horizontal multi-link elbow-type cold extrusion press, places the grooved lower die into the automatically centering die seat, and the punch is made of carbide material. A disc-type feeding mechanism is used to cold-extrude the aluminum billet that has been stirred and coated with light zinc stearate powder into a round explosion-proof power battery aluminum shell at one time.

[0007] By adopting the above technical solution, the lubrication adhesion of the billet before extrusion is increased, and the ability of plastic deformation during metal extrusion is improved. Then the billet is slinged by a circular cage to prevent the billet from colliding with it during lubrication, and the billet is not easily deformed.

[0008] Preferably, the aluminum billet is cold extruded in step 3 by forward extrusion, i.e., bottom forming, reverse extrusion, i.e., sidewall forming, and radial local extrusion.

[0009] By adopting the above technical solution, the blank can be formed in one piece without welds, and the explosion-proof ribs can be formed simultaneously with high consistency, while the material can achieve the highest utilization rate.

[0010] Preferably, corresponding grooves are provided in the lower die and at the top of the punch rod used for radial local extrusion, and the grooves of the lower die and at the top of the punch rod are adapted to each other.

[0011] Preferably, the groove at the end of the punch rod is cross-shaped as a whole, the center of the groove is circular, the circle is a groove lower than the surface of the punch rod, and there is a circle of bulges around the circle. The cross is a waist-shaped groove sunken into the surface of the punch rod, and the corresponding grooves of the lower die and the punch rod are in opposite directions.

[0012] By adopting the above technical solution, the extruded product has an explosion-proof function. When the pressure of a single battery aluminum can exceeds a certain level, the battery aluminum can explodes, preventing all batteries from exploding. This effectively reduces or avoids vehicle explosions caused by battery problems. It is also beneficial to find problems with a single battery and replace it, thereby improving convenience.

[0013] Preferably, the punch rod is located in the punch rod chuck, and the outside of the punch rod chuck is fastened by a punch cylinder seat nut. A punch rod pad and a pad are sequentially provided at the bottom of the punch rod, and a punch cylinder seat pad is provided on one side of the pad.

[0014] Preferably, the lower die cavity is located in the integral die, the lower die cavity is located in the die seat, a die seat cushion block is provided on one side of the die seat, and the die seat fastens the lower die cavity through a clamping block and a tightening screw.

[0015] By adopting the above technical solution, the punch and the lower die groove cooperate with each other to cold extrude the blank into a product.

[0016] Preferably, the shape between the lower die and the punch conforms to the shape of the product, the new energy vehicle power battery aluminum can, and the aluminum round billets used for cold extrusion are mostly first-series pure aluminum.

[0017] By adopting the above technical solution, the punch is made of carbide material and uses a disc-type feeding mechanism, which makes the feeding and extrusion more precise. The upper and lower molds are made of carbide material, which is more durable and has more stable dimensions. The mold has higher red hardness and greater reliability.

[0018] The benefits of the present invention are as follows: 1. The present invention provides corresponding explosion-proof grooves on the punch and the die, and the blank enters the punch and the die for cold extrusion molding. The extruded product has an explosion-proof function. When a single battery aluminum can exceeds a certain pressure, the battery aluminum can explodes, avoiding the explosion of all batteries, effectively reducing or avoiding vehicle explosions caused by battery problems.

[0019] 2. The present invention uses shot blasting process to increase the lubrication adhesion of the billet before extrusion and improve the ability of plastic deformation during metal extrusion. Then the billet is thrown into a circular cage to prevent the billet from colliding with it during lubrication, and the billet is not easily deformed.

[0020] 3. The grain structure of the aluminum shell after cold extrusion of the present invention is denser, which prolongs the service life of the explosion-proof battery. The thermal conductivity and thermal stability of the cold-extruded explosion-proof battery aluminum shell are better, which helps to dissipate heat from the battery and greatly improves safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of cold extrusion of the present invention; Figure 2 It is a structural schematic diagram of the lower die concave die of the present invention; Figure 3 For the present invention Figure 2 A schematic structural diagram of the enlarged view of part A; Figure 4 This is a schematic structural diagram of a top view of the lower die concave die of the present invention; Figure 5 It is a structural schematic diagram of the punch rod of the present invention; Figure 6 For the present invention Figure 4 Schematic diagram of the structure of the enlarged view of part B.

[0022] Among them: 1. tightening screw, 2. die seat pad, 3. die seat, 4. clamping block, 5. die pad, 6. lower die, 7. punch cylinder seat nut, 8. punch rod pad, 9. pad, 10. punch cylinder seat, 11. punch cylinder seat pad, 12. integral die, 13. punch rod, 14. punch rod chuck, 15. groove, 15-1, round, 15-2, waist-shaped. DETAILED DESCRIPTION

[0023] The technical solutions in the embodiments of the present invention will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present invention.

[0024] like Figure 1 As shown, a cold extrusion forming process for a round aluminum shell with an explosion-proof power battery for a new energy vehicle is characterized by comprising the following steps: Step 1: Make aluminum round billet: Design the billet size according to the shape, size, weight and performance parameter requirements of the power battery aluminum shell; Step 2: Lubricate the aluminum round billet: The aluminum billet is processed by continuous casting and rolling process. The round or square billet formed by blanking is subjected to shot blasting process to increase the lubrication of the billet before extrusion. Light zinc stearate powder is stirred and applied to the aluminum billet using a stirring device; Step 3: Cold extrusion forming uses a horizontal multi-link elbow-type cold extrusion press, places the grooved lower die 6 into the automatically centering die base 3, the punch 13 is made of cemented carbide material, and uses a disc-type feeding mechanism. The aluminum billet is stirred and coated with light zinc stearate powder and is cold-extruded into a round explosion-proof power battery aluminum shell in one go using a circular cage.

[0025] Stir and apply light zinc stearate powder in step 2, and expose it to the sun at 25°C for 3 hours before use. Store it in a moisture-proof and humidity-proof manner to increase the lubrication adhesion of the billet before extrusion and improve the ability of plastic deformation during metal extrusion. Then use a round sling cage to prevent the billet from colliding with it during lubrication, so that the billet is not easily deformed.

[0026] In step 3, the aluminum billet is cold extruded through forward extrusion, i.e. bottom forming, reverse extrusion, i.e. side wall forming, and radial local extrusion. The billet can be formed as a whole without welds, and can be formed simultaneously with explosion-proof ribs, with high consistency and the highest material utilization rate.

[0027] like Figure 2-6 As shown, corresponding grooves 15 are provided in the lower die 6 and at the top of the punch 13 used for radial local extrusion, and the grooves 15 on the lower die 6 and the top of the punch 13 are adapted to each other.

[0028] The groove 15 at the end of the punch rod 13 is cross-shaped as a whole, and the center of the groove 15 is circular. The circle 15-1 is a groove lower than the surface of the punch rod 13, and there is a circle of bulges around the circle 15-1. The cross is a waist-shaped 15-2 sunken in the surface of the punch rod 13. The grooves 15 corresponding to the lower die 6 and the punch rod 13 are in opposite directions. The extruded product has an explosion-proof function. When a single-cell battery aluminum can exceeds a certain pressure, the battery aluminum can explodes alone to avoid the explosion of all batteries, effectively reducing or avoiding vehicle explosions caused by battery problems, and is also conducive to finding problems with single batteries, which can be replaced to improve convenience.

[0029] The punch rod 13 is located in the punch rod chuck 14, and the outside of the punch rod chuck 14 is fastened by the nut of the punch cylinder seat 10. The bottom of the punch rod 13 is provided with a punch rod pad 11 and a pad 9 in sequence, and a cylinder seat pad 11 is provided on one side of the pad 9. The lower die cavity 6 is located in the overall cavity 12, and the lower die cavity 6 is located in the cavity seat 3. A cavity seat pad 2 is provided on one side of the cavity seat 3. The cavity seat 3 fastens the lower die cavity 6 through the clamping block 4 and the tightening screw 1. The punch rod 13 and the lower die groove 6 cooperate with each other to cold extrude the blank into a product.

[0030] The shape between the lower die 6 and the punch 13 conforms to the product's new energy vehicle power battery aluminum can. The aluminum round billets used for cold extrusion are mostly first-series pure aluminum. The punch 13 is made of carbide material and uses a disc-type feeding mechanism, which makes the feeding and extrusion more precise. The upper and lower dies are made of carbide material, which is more durable and has more stable dimensions. The mold has higher red hardness and greater reliability.

[0031] A horizontal multi-link toggle-type cold extrusion press is used to cold-extrude aluminum round billets into round explosion-proof power battery aluminum shells suitable for new energy vehicles that meet the requirements in one go, replacing the traditional process. Depending on the product size, the one-time extrusion forming speed of round explosion-proof power battery aluminum shells for new energy vehicles can generally be 50-70 pieces per minute, achieving a material utilization rate of up to 95%, which is about 20% higher than the current traditional process and reducing production costs. The one-time cold extrusion forming process of this process has good plastic deformation of the aluminum shell, improved tensile strength, compressive strength and bending strength, and enhanced the mechanical properties of the battery shell; through forward extrusion (bottom forming) + reverse extrusion (sidewall forming) + radial local extrusion (with explosion-proof valve grooves), one-piece forming is seamless, and explosion-proof ribs can be formed simultaneously with high consistency; the grain structure of the aluminum shell after cold extrusion is denser, extending the service life of the explosion-proof battery, and the cold-extruded explosion-proof battery aluminum shell has better thermal conductivity and thermal stability, which helps dissipate heat from the battery and greatly improves safety.

[0032] Those skilled in the art will understand that the embodiments of the present invention described above and shown in the accompanying drawings are intended to be illustrative only and are not intended to limit the present invention. The objectives of the present invention have been fully and effectively achieved. The functional and structural principles of the present invention have been demonstrated and illustrated in the embodiments. Any variations or modifications may be made to the embodiments of the present invention without departing from the principles described.

Claims

1. A cold extrusion forming process for a round aluminum shell with explosion-proof power battery for new energy vehicles, characterized in that: The following steps are involved: Step 1: Make aluminum round billet: Design the billet size according to the shape, size, weight and performance parameter requirements of the power battery aluminum shell; Step 2: Lubricate the aluminum round billet: The aluminum billet is processed by continuous casting and rolling process. The round or square billet formed by blanking is subjected to shot blasting process to increase the lubrication of the billet before extrusion. A stirring device is used to stir and apply light zinc stearate powder on the aluminum billet. The light zinc stearate powder is exposed to the sun at 25°C for 3 hours before use. It is moisture-proof and humidity-proof. The dosage is 120g of light zinc stearate powder for every 100kg of billet. The application and stirring are carried out for 18-20 minutes. Step 3: Cold extrusion forming uses a horizontal multi-link elbow-type cold extrusion press, places the grooved lower die into the automatically centering die seat, and the punch is made of carbide material. A disc-type feeding mechanism is used to cold-extrude the aluminum billet that has been stirred and coated with light zinc stearate powder into a round explosion-proof power battery aluminum shell at one time.

2. The cold extrusion forming process of a round explosion-proof power battery aluminum shell for new energy vehicles according to claim 1 is characterized in that: In step 3, the aluminum billet is cold extruded through forward extrusion, i.e., bottom forming, reverse extrusion, i.e., sidewall forming, and radial local extrusion.

3. The cold extrusion forming process of a round explosion-proof power battery aluminum shell for new energy vehicles according to claim 2 is characterized in that: The lower die used for the radial local extrusion and the top of the punch are provided with corresponding grooves, and the grooves of the lower die and the top of the punch are adapted to each other.

4. The cold extrusion forming process of a round explosion-proof power battery aluminum shell for new energy vehicles according to claim 3 is characterized in that: The groove at the end of the punch rod is cross-shaped as a whole, the center of the groove is a circle, the circle is a groove lower than the surface of the punch rod, and there is a circle of bulges around the circle. The cross is a waist shape sunken into the surface of the punch rod, and the grooves corresponding to the lower die and the punch rod are in opposite directions.

5. The cold extrusion forming process of a round explosion-proof power battery aluminum shell for new energy vehicles according to claim 3 is characterized in that: The punch rod is located in the punch rod chuck, and the outside of the punch rod chuck is fastened by a punch cylinder seat nut. A punch rod pad and a pad are sequentially provided at the bottom of the punch rod, and a punch cylinder seat pad is provided on one side of the pad.

6. The cold extrusion forming process of a round explosion-proof power battery aluminum shell for new energy vehicles according to claim 3 is characterized in that: The lower die cavity is located in the integral die, and the lower die cavity is located in the die seat. A die seat cushion block is provided on one side of the die seat, and the die seat fastens the lower die cavity through a clamping block and a tightening screw.

7. The cold extrusion forming process of a round explosion-proof power battery aluminum shell for new energy vehicles according to claim 1 is characterized in that: The shape between the lower die and the punch conforms to the shape of the new energy vehicle power battery aluminum can, and the aluminum round billets used for cold extrusion are mostly pure aluminum.

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