U-shaped battery box cover plate broadening extrusion die

Abstract

The utility model discloses a U-shaped battery box cover plate broadsiding extrusion die which comprises a broadsiding material channel and a horizontal flow die, and the broadsiding material channel is composed of a first-stage broadsiding material channel and a second-stage broadsiding material channel; the broadening rate of the first-stage broadening material channel is 55-60%, the broadening rate of the second-stage broadening material channel is 25-30%, and the broadening rate of the whole broadening material channel is 90-99%. By arranging the two stages of broadening material channels, the broadening rate of 99% can be achieved and far exceeds the broadening amplitude of an existing mold, and the effects that large materials can be discharged through a small machine, and the aluminum extrusion production cost is greatly reduced can be achieved.

Description

Technical Field

[0001] This application relates to the technical field of extrusion dies, and particularly to a U-shaped battery case cover wide-spread extrusion die. Background Art

[0002] As a key component of the lithium-ion battery system, the battery case plays a role in fixing and fully sealing the internal electrochemical system. Its structural strength, heat dissipation and other performances are important indicators for measuring the working ability of lithium-ion batteries. Aluminum alloy has good thermal conductivity, strong plasticity, light weight, corrosion resistance, and is easy to recycle and regenerate, and is the preferred material for the battery case.

[0003] The width of the case of a large-capacity lithium-ion battery can reach about 500 mm, and the aluminum extrusion wide-spread technology needs to be used for extrusion molding. The aluminum extrusion wide-spread technology is an important process in the field of aluminum profile processing. Its principle is to set a deflector with a wide-spread function at the front end of the die, so that the round ingot generates pre-deformation during extrusion. Under the action of the deflector, the cross-section of the ingot gradually approaches the profile cross-section size. Through the wide-spread of the diversion hole and subsequent secondary deformation, the production of large-size profiles with an external diameter exceeding the diameter of the extrusion cylinder is realized. The wide-spread amplitude of the existing extrusion die is generally 40%-50%, and it is necessary to use a relatively large-diameter aluminum rod for extrusion in a large extrusion press, resulting in high extrusion energy consumption, large equipment investment, and high production cost. Utility Model Content

[0004] To solve the above technical problems, this application provides a U-shaped battery case cover wide-spread extrusion die.

[0005] The technical solution adopted in this application is:

[0006] A U-shaped battery case cover wide-spread extrusion die includes a wide-spread channel and a flat-flow die. The wide-spread channel consists of a primary wide-spread channel and a secondary wide-spread channel; the wide-spread rate of the primary wide-spread channel is 55-60%, the wide-spread rate of the secondary wide-spread channel is 25-30%, and the wide-spread rate of the entire wide-spread channel is 90-99%.

[0007] Wide-spread rate = (external diameter of the circumcircle at the die outlet - external diameter of the circumcircle at the die inlet) / external diameter of the circumcircle at the die inlet.

[0008] The primary wide-spread channel first contacts the metal during aluminum extrusion, mainly playing the role of initially guiding the metal flow and starting the wide-spread. It provides an initial lateral flow direction and space for the metal to enter the die system. The primary wide-spread channel mainly affects the initial flow direction and speed of aluminum, and plays a guiding role in the wide-spread of aluminum. Its main purpose is to make the aluminum wide-spread faster and reach the size required for the secondary wide-spread.

[0009] The secondary spreading channel plays a role after the metal passes through the primary spreading channel, further adjusting and optimizing the flow state of the metal to make the spreading more uniform and sufficient, ensuring that the metal can better fill the die cavity. Its size design mainly depends on the profile dimensions. Based on the primary spreading channel, it further optimizes the metal flow state to make the spreading more uniform and stable. It has an important impact on the final filling effect of the metal and the product quality. The role of the secondary spreading channel is to perform the final spreading adjustment on the product to ensure the dimensional accuracy and surface quality of the product.

[0010] The primary spreading ratio is greater than the secondary spreading ratio, making the resistance of aluminum in the secondary spreading channel greater than that in the primary spreading channel. According to the principle of metal fluidity, aluminum will preferentially flow to the place with less resistance. Therefore, aluminum will first fill the entire primary spreading channel and then enter the secondary spreading channel for secondary spreading, so that aluminum can enter the flat die evenly and smoothly.

[0011] Furthermore, the outer diameter of the circumscribed circle of the feed inlet of the primary spreading channel is 5 - 10 mm smaller than the diameter of the extrusion cylinder. The outer diameter of the circumscribed circle of the feed inlet of the secondary spreading channel is concentric with and equal to the outer diameter of the circumscribed circle of the discharge outlet of the primary spreading channel. The shape and size of the middle part of the feed inlet of the secondary spreading channel are smaller than those of the middle part of the discharge outlet of the primary spreading channel.

[0012] It is necessary for all extrusion dies that the outer diameter of the circumscribed circle of the feed inlet is smaller than the diameter of the extrusion cylinder because the aluminum rod needs to be upset in the extrusion cylinder first. With a total diameter of 305 mm, it is upset to a diameter of 313 mm and then enters the feed inlet of the die. If the feed inlet is larger than the diameter of the extrusion cylinder, the aluminum rod may directly enter the die.

[0013] The outer diameter of the circumscribed circle of the feed inlet of the secondary spreading channel is concentric with and equal to the outer diameter of the circumscribed circle of the discharge outlet of the primary spreading channel, which can make aluminum flow smoothly into the secondary spreading channel. The shape and size of the middle part of the feed inlet of the secondary spreading channel are smaller than those of the middle part of the discharge outlet of the primary spreading channel, further increasing the flow resistance of aluminum in the secondary spreading channel, ensuring that aluminum first fills the entire primary spreading channel, and making the flow resistance of aluminum entering the middle part of the secondary spreading channel greater than that at both ends, so that aluminum flows towards both ends as much as possible to improve the forming effect.

[0014] Furthermore, the net height of the feed inlet of the secondary spreading channel is smaller than the net height of the discharge outlet of the primary spreading channel to improve the forming effect.

[0015] Furthermore, the first-stage spreading channel includes a first-stage channel body, in which a first feeding channel is formed. The cross-section of the first feeding channel is U-shaped. The left and right outer side surfaces of the first feeding channel gradually expand from the feeding port to the discharging port, with an expansion angle of 32° - 36°; the upper and lower side surfaces in the middle part of the first feeding channel gradually expand from the feeding port to the discharging port, with an expansion angle of 2° - 5°.

[0016] By adopting the design scheme with a small spreading angle in the middle thickness direction and a large spreading angle in the two side width directions, the aluminum flow resistance in the middle of the profile can be strengthened, driving the aluminum to both sides to better meet the feeding requirements at both ends of the profile, ensuring the overall feeding balance of the profile, enabling the profile to discharge better, and thus ensuring the dimensional accuracy of the profile. The expansion angle is the included angle between the left and right outer side surfaces of the feeding channel and the channel center line.

[0017] Furthermore, the thickness of the first-stage spreading channel is 120 - 160 mm. The thickness of the channel is related to the spreading angle. If the spreading angle is too large, the fluidity of the aluminum will cause uneven filling.

[0018] Furthermore, the second-stage spreading channel includes a second-stage channel body, in which a second feeding channel is formed. The cross-section of the second feeding channel is U-shaped. The left and right outer side surfaces of the second feeding channel gradually expand from the feeding port to the discharging port, with an expansion angle of 18° - 22°; the upper and lower side surfaces in the middle part of the second feeding channel gradually expand from the feeding port to the discharging port, with an expansion angle of 1° - 3°.

[0019] Furthermore, the thickness of the second-stage spreading channel is 160 - 200 mm.

[0020] Furthermore, the first-stage spreading channel, the second-stage spreading channel, and the flat die are sequentially and fixedly connected by pins.

[0021] The pins can provide precise positioning between the various components of the die, ensuring that the relative positions of all parts are accurate after the die is assembled. This is crucial for ensuring the dimensional accuracy and shape accuracy of the aluminum profile. The pin connection has a high connection strength and can withstand the huge pressure and impact force during the aluminum extrusion process. The pins are usually made of high-strength materials, such as alloy steel, which have good hardness and toughness after heat treatment, ensuring that the die will not loosen or be damaged during long-term use.

[0022] Advantages of the present utility model: The difficulty of the spread extrusion design is how to ensure the dimensional accuracy of the extruded product. In this application, by designing that the first-stage spread ratio is greater than the second-stage spread ratio, the resistance of aluminum in the second-stage spread channel is greater than that in the first-stage spread channel. According to the principle of metal fluidity, aluminum will flow preferentially to the place with less resistance. Therefore, aluminum will preferentially fill the entire first-stage spread channel and then enter the second-stage spread channel for secondary spreading, so that aluminum can enter the flat die smoothly and evenly, thereby improving the dimensional accuracy of the product of the spread extrusion. By setting two-stage spread channels in this application, a spread ratio of 99% can be achieved, far exceeding the spread range of existing molds. Using this application can achieve small machines producing large materials, greatly reducing the production cost of aluminum extrusion. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a schematic cross-sectional view of the extrusion of the U-shaped battery box cover plate.

[0024] Figure 2 is a schematic three-dimensional structure view of the spread extrusion die for the U-shaped battery box cover plate of this application.

[0025] Figure 3 is a schematic three-dimensional structure view of the first-stage spread channel of this application.

[0026] Figure 4 is a schematic plan view of the first-stage spread channel of this application.

[0027] Figure 5 is Figure 4 the sectional view taken along the direction A of

[0028] Figure 6 is Figure 4 the sectional view taken along the direction B of

[0029] Figure 7 is a schematic three-dimensional structure view of the second-stage spread channel of this application.

[0030] Figure 8 is a schematic plan view of the second-stage spread channel of this application.

[0031] Figure 9 is Figure 8 the sectional view taken along the direction A of

[0032] Figure 10 is Figure 8 the sectional view taken along the direction B of

[0033] Figure 11 is a schematic plan view of the flat die of this application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0034] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below in conjunction with the accompanying drawings and a preferred embodiment.

[0035] Referring to Figure 2 , this embodiment provides a U-shaped battery box cover plate wide expansion extrusion die, which includes a primary wide expansion channel 10, a secondary wide expansion channel 20, and a flat flow die 30.

[0036] Referring to Figures 3 - 6 , the primary wide expansion channel 10 includes a primary channel body, which is oblate cylindrical. An axial first feed channel 11 is opened inside it. The cross-section of the first feed channel 11 is U-shaped. The feed width at both ends of the U-shaped channel is greater than the feed width at its middle part. The difficulty of the wide expansion extrusion technology is the difficult aluminum feeding at both ends. Therefore, it is necessary to push the aluminum towards both ends. The more aluminum feeding at both ends, the better. Therefore, the width at both ends of the channel is large and the middle is small, increasing the resistance at the middle part.

[0037] The front opening of the first feed channel 11 is the feed port 101 of the primary wide expansion channel 10, and the rear opening is the discharge port 102 of the primary wide expansion channel 10. The center of the circumcircle of the discharge port 102 is concentric with the channel body. The position of the feed port 101 on the channel body is adapted to the position of the extrusion port of the extruder to adapt to the extrusion of the product.

[0038] The diameter of the circumcircle of the feed port 101 is 5 - 10 mm smaller than the diameter of the extrusion cylinder, so that the aluminum rod is first upset in the extrusion cylinder. For example, in this embodiment, an aluminum rod with a diameter of 305 mm is upset to a diameter of 313 mm and then enters the feed port of the die. If the feed port is larger than the diameter of the extrusion cylinder, the aluminum rod will directly enter the die.

[0039] The left and right outer side surfaces of the first feed channel gradually expand from the feed port 101 to the discharge port 102, and the upper and lower side surfaces in the middle part of the first feed channel gradually expand from the feed port 101 to the discharge port 102. In this embodiment, the diameter of the circumcircle of the feed port 101 is 303 mm, the diameter of the circumcircle of the discharge port 102 is 478.7 mm, the width of the discharge port 102 is 464.5 mm, and the expansion angle of the left and right outer side surfaces is 34°; the narrowest distance in the middle part of the feed port 101 is 41.9 mm, the narrowest distance in the middle part of the discharge port 102 is 56.6 mm, and the expansion angle of the upper and lower side surfaces is 3°. In other embodiments, the expansion angle of the left and right outer side surfaces can be selected within the range of 32° - 36°, and the expansion angle of the upper and lower side surfaces can be selected within the range of 2° - 5°.

[0040] The thickness of the primary channel body is the thickness of the primary spreading channel 10. In this embodiment, the thickness of the primary spreading channel 10 is 140 mm. In other embodiments, the thickness of the primary spreading channel 10 can be selected within the range of 120 - 160 mm.

[0041] Refer to Figures 7 - 10 , the secondary spreading channel 20 includes a secondary channel body. The secondary channel body is in a flat cylindrical shape, and a second feed channel 21 is axially formed inside it. The cross-section of the second feed channel 21 is in a U shape. The front opening of the second feed channel 21 is the feed port 201 of the secondary spreading channel 20, and the rear opening is the discharge port 202 of the secondary spreading channel 20; the circumcircle of the feed port 201, the circumcircle of the discharge port 202, and the circumcircle of the discharge port of the primary spreading channel are concentric. The shape and size of the feed port 201 are basically the same as those of the discharge port 102, except that the size of the middle part of the feed port 201 is smaller than that of the middle part of the discharge port 102.

[0042] The left and right outer side surfaces of the second feed channel gradually expand from the feed port 201 to the discharge port 202, and the upper and lower side surfaces of the middle part of the second feed channel gradually expand from the feed port 201 to the discharge port 202. In this embodiment, the circumcircle diameter of the feed port 201 is 478.7 mm, the circumcircle diameter of the discharge port 202 is 604.2 mm, the width of the feed port 201 is 464.5 mm, the width of the discharge port 202 is 595.5 mm, and the expansion angle of the left and right outer side surfaces is 20°; the narrowest distance of the middle part of the feed port 201 is 36 mm, the narrowest distance of the middle part of the discharge port 202 is 40 mm, and the expansion angle of the upper and lower side surfaces is 1°. In other embodiments, the expansion angle of the left and right outer side surfaces can be selected within the range of 18° - 22°, and the expansion angle of the upper and lower side surfaces can be selected within the range of 1° - 3°.

[0043] The thickness of the secondary channel body is the thickness of the secondary spreading channel 20. In this embodiment, the thickness of the secondary spreading channel 20 is 180 mm. In other embodiments, the thickness of the secondary spreading channel 20 can be selected within the range of 160 - 200.

[0044] In this embodiment, the spreading rate of the primary spreading channel is (478.7 - 303) / 303 = 58%. The spreading rate of the secondary spreading channel is (604.2 - 478.7) / 478.7 = 26%. The spreading rate of the entire spreading channel is (604.2 - 303) / 303 = 99%.

[0045] Refer to Figure 11 , in this embodiment, the thickness of the flat die 30 is 120 mm. The design of the flat die is a prior art. In this application, the discharge state and size of the die are mainly adjusted by adding a baffle block to ensure that the extruded profile meets the dimensional requirements.

[0046] The overall structure of the die is as Figure 2 shown. The first-stage spreading channel 10, the second-stage spreading channel 20 and the flat-flow die 30 are sequentially fixedly connected by screws and pins. After assembly, they are placed together in the die holder of the extruder, aligning the feed port of the first-stage spreading channel 10 with the discharge port of the extrusion cylinder. Aluminum enters from the feed port 101 of the first-stage spreading channel, and after two-stage spreading, it enters the flat-flow die 30 from the discharge port 202, is extruded into the required product cross-sectional shape in the flat-flow die, and then discharges from the discharge port of the flat-flow die.

[0047] This application uses a 4500T extruder with an extrusion cylinder diameter of 313mm. An aluminum rod with a material grade of 6063-T5 and a diameter of 305mm is selected for extrusion. The cross-sectional view of the extruded product is as Figure 1 shown.

[0048] The specific method is as follows:

[0049] First, the aluminum rod to be extruded is placed in a single-rod furnace and heated to 480°C. At the same time, the die is also placed in a die furnace, heated to 480°C and kept warm for 4h, and the extrusion cylinder is heated to 450°C.

[0050] After the heating and heat preservation are completed, the die is placed in the die holder of the extruder, and the aluminum rod is sent into the extrusion cylinder by a manipulator to start extrusion.

[0051] After the aluminum rod is upset in the extrusion cylinder, it first enters the first-stage spreading channel 10. After passing through the first-stage spreading channel, the size of the aluminum rod spreads from 303mm to 478.7mm. Subsequently, it enters the second-stage spreading channel 20, and finally spreads to 604.2mm at a spreading angle of 20°. Finally, it enters the flat-flow die 30. The discharge speed of the profile is selected as 5m / min, and the formed product is extruded from the discharge port of the flat-flow die.

[0052] Through the above design scheme, we have successfully extruded profiles that originally required a 6000T extruder using a 4000T extruder, achieving the extrusion of large profiles with a small machine, and greatly reducing the production cost of aluminum extrusion.

[0053] The above is only the preferred embodiment of this application. It should be noted that for those of ordinary skill in the art, without departing from the principle of this application, several improvements and refinements can still be made, and these improvements and refinements are also within the protection scope of this application.

Claims

1. A U-shaped battery box cover stretching extrusion die, comprising a stretching material channel and a flat flow die, characterized in that, The spreading channel is composed of a primary spreading channel and a secondary spreading channel; the spreading rate of the primary spreading channel is 55 - 60%, the spreading rate of the secondary spreading channel is 25 - 30%, and the spreading rate of the whole spreading channel is 90 - 99%.

2. The U-shaped battery box cover plate stretching extrusion die according to claim 1, characterized in that, The diameter of the circumscribed circle of the inlet of the primary spreading channel is 5 - 10 mm smaller than the diameter of the extrusion cylinder. The circumscribed circle of the inlet of the secondary spreading channel is concentric with and has the same diameter as the circumscribed circle of the outlet of the primary spreading channel. The shape and size of the middle part of the inlet of the secondary spreading channel are smaller than those of the middle part of the outlet of the primary spreading channel.

3. The U-shaped battery box cover plate stretching extrusion die according to claim 2, wherein, The net height of the middle part of the inlet of the secondary spreading channel is smaller than that of the middle part of the outlet of the primary spreading channel.

4. A U-shaped battery box cover stretching extrusion die according to claim 1 or 2, characterized in that, The primary spreading channel includes a primary channel body. A first feeding channel is arranged in the primary channel body. The cross-section of the first feeding channel is U-shaped. The left and right outer side surfaces of the first feeding channel gradually expand from the inlet to the outlet, and the expansion angle is 32° - 36°. The upper and lower side surfaces of the middle part of the first feeding channel gradually expand from the inlet to the outlet, and the expansion angle is 2° - 5°.

5. A U-shaped battery box cover plate stretching extrusion die according to claim 4, characterized in that, The thickness of the primary spreading channel is 120 - 160 mm.

6. A U-shaped battery box cover stretching extrusion die according to claim 1 or 2, characterized in that The secondary spreading channel includes a secondary channel body. A second feeding channel is arranged in the secondary channel body. The cross-section of the second feeding channel is U-shaped. The left and right outer side surfaces of the second feeding channel gradually expand from the inlet to the outlet, and the expansion angle is 18° - 22°. The upper and lower side surfaces of the middle part of the second feeding channel gradually expand from the inlet to the outlet, and the expansion angle is 1° - 3°.

7. An extended extrusion die for the U-shaped battery box cover plate according to claim 6, characterized in that, The thickness of the secondary spreading channel is 160 - 200 mm.

8. An extended extrusion die for the U-shaped battery box cover plate according to claim 1 or 2, characterized in that The primary spreading channel, the secondary spreading channel, and the flat flow die are sequentially fixedly connected by pins.

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