Double-injection-position integrated battery shell pouring and discharging system and pouring method

Abstract

The invention relates to the technical field of lower vehicle bodies of electric vehicles, in particular to a double-injection-position integrated battery shell pouring and discharging system and a pouring method. The pouring and discharging system comprises a pouring structure and a cinder ladle; the pouring structures are symmetrically arranged on the two sides, provided with the wheel covers, of the battery shell, each pouring structure comprises a material cake and a transverse pouring channel, the transverse pouring channels are reversely upward in the gravity direction, the sectional areas of the transverse pouring channels are gradually reduced, one ends of the transverse pouring channels are connected with the material cakes, and the other ends of the transverse pouring channels are connected with the battery shell to form inner pouring gates. The flow gates are arranged according to the edge shape of the battery shell; the cinder ladle is positioned on the edge of the middle of the battery shell. Through the design of the double injection positions, the problems in the prior art are solved, the elongation performance of the wheel casing and the connecting position of the tail end and the front floor of the product is improved, the qualified rate of spr connecting points of the product is increased, the defects in the production process are reduced, and the production efficiency and the product quality are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of electric vehicle undercarriages, and in particular to a dual-shot-position integrated battery shell pouring system and a pouring method. Background Art

[0002] In the field of electric vehicle manufacturing, the battery shell is a key structural component, and its production method directly affects the safety, performance and manufacturing cost of the entire vehicle. Traditional battery shell production mainly relies on processes such as extrusion, stamping and welding assembly. These methods are prone to matching and connection problems during the manufacturing process due to the large number of parts (the number of extrusions and stampings for the entire rear body is as many as 50), and it also poses a huge challenge to the control of product size.

[0003] Among the existing technologies, some automobile manufacturers have begun to try to use the pouring system of the one-piece die-cast aluminum rear body to reduce the number of parts and simplify the production process. These systems generally adopt single-side pouring (such as Figure 1 as shown) or center pouring (as shown Figure 2 The method shown in the figure has some inherent disadvantages, such as the gate is far away from the wheel cover and the end of the product, which makes it impossible to guarantee the elongation performance of the end and wheel cover, and increases the risk of cracking in the spr (holeless self-piercing rivet) process. In addition, the traditional one-piece rear body pouring method is limited to the center pouring, which can arrange a small gate area, and the aluminum liquid flow is relatively small, which will increase the overall time of aluminum liquid filling the product. The aluminum liquid temperature drops significantly during the filling process, and the product is prone to defects such as cold shut flow marks.

[0004] Based on the existing technology, the following technical problems can be analyzed:

[0005] 1. Single-side or center-side pouring methods result in insufficient elongation performance at the wheel arch and the end of the product, affecting the stability of the SPR process and the mechanical properties of the product.

[0006] 2. The small area of ​​the inner gate leads to insufficient aluminum liquid flow, which increases the overall time for the aluminum liquid to fill the product, thereby increasing the risk of defects such as cold shut flow marks in the product.

[0007] 3. The traditional pouring system cannot effectively improve the elongation performance of the product at the wheel arch and the connection between the end and the front floor, which limits the mechanical properties and qualification rate of the product. Summary of the invention

[0008] In view of the shortcomings of the prior art, the purpose of an embodiment of the present invention is to provide a dual-shot integrated battery shell pouring system. Through the design of dual-shot positions, the problems in the prior art are solved, the elongation performance of the product at the wheel arch and the connection between the end and the front floor is improved, the qualified rate of the product's SPR connection points is improved, defects in the production process are reduced, and production efficiency and product quality are improved.

[0009] In order to achieve the above objectives, the embodiments of the present invention provide the following technical solutions:

[0010] A dual-shot integrated battery shell pouring system, comprising: a pouring structure and a slag bag; the pouring structure is symmetrically arranged on both sides of the battery shell having a wheel cover, the pouring structure comprises a material cake and a cross runner, the cross runner is upward in the opposite direction of gravity, and the cross-sectional area of ​​the cross runner gradually decreases, one end of the cross runner is connected to the material cake, and the other end of the cross runner is connected to the battery shell to form an inner gate, and the inner gate is arranged according to the edge shape of the battery shell; the slag bag is located at the edge of the middle part of the battery shell.

[0011] The pouring structure is symmetrically arranged on both sides of the battery shell, specifically on both sides of the wheel housing. This design ensures that the molten aluminum can flow into all parts of the battery shell simultaneously and evenly when filling by placing the pouring system symmetrically on both sides of the battery shell. This symmetrical design effectively reduces the unevenness during the filling process, especially in the wheel housing area and the end of the battery shell. This symmetrical arrangement also ensures the consistency of mechanical properties at both ends of the product, thereby reducing the risk of defects caused by uneven filling during the production process.

[0012] The runner is directed upward in the opposite direction of gravity, and the cross-sectional area gradually decreases. This design accelerates the aluminum liquid during the flow process and reaches an ideal flow speed, thereby improving the casting efficiency. The increase in the flow speed of the aluminum liquid helps the aluminum liquid to better fill various parts of the battery shell, especially the wheel cover and the end parts, avoiding the common cold shut flow marks and insufficient filling.

[0013] The fully conformal ingate design allows for more precise control of the aluminum liquid's inflow path, ensuring that the aluminum liquid first fills key parts of the battery shell, such as the wheel cover edge and the end of the battery shell. This precisely arranged ingate effectively prevents the problem of insufficient filling in traditional runner designs. The slag bag is located at the edge of the middle of the battery shell, and its function is to collect the slower cooling aluminum liquid and filter out impurities in the aluminum liquid. The slag bag design can effectively reduce the risk of defects caused by uneven cooling at the end of the product. By setting a slag bag in the middle of the battery shell, the fluidity of the aluminum liquid can be further optimized, ensuring that the aluminum liquid can enter various parts of the battery shell at a suitable temperature and flow rate, and improving the filling quality.

[0014] Optionally, the material cake is a disc-shaped structure, the material cake thickness is 30±5mm, and the material cake diameter is ≥220mm. The thickness within the range of 30±5mm can not only increase the thickness of the gate and improve the stability of the aluminum liquid flow, but also ensure that the material cake is not prone to cracks or deformation during the production process. The design of diameter ≥220mm helps to improve the uniformity and speed of aluminum liquid inflow, and further improve the filling quality of aluminum liquid, especially in the inner gate area. Such a design size can not only effectively support the flow of aluminum liquid, but also ensure that the aluminum liquid will not affect the entire filling process due to the cracking or deformation of the material cake during the die-casting process. The design of thickness and diameter takes into account the stability of aluminum liquid flow. Sufficient thickness can withstand greater pressure and prevent the material cake from bursting during the pouring process, thereby ensuring the safety and stability of the entire pouring system.

[0015] Optionally, the runner is divided into multiple branch runners, and each branch runner is divided into multiple ingates. Specifically, the runner is divided into two branch runners, and each branch runner is divided into 6 ingates. Dividing the runner into two branch runners can make the molten aluminum more evenly distributed in the process of entering the mold, reducing the risk of air bubbles and slag entrainment. Each branch runner is further divided into 6 ingates. This design helps to fill the mold simultaneously at multiple gates, reducing the difference in aluminum liquid flow rate in each part during the filling process, thereby avoiding local overfilling or underfilling. The number and layout of the ingates optimize the filling of the mold and improve the density and surface quality of the molded product. In addition, this runner distribution method also effectively reduces the deformation problem caused by uneven cooling, improves the overall casting stability and mechanical properties of the finished product.

[0016] Optionally, the area of ​​the overall ingate is ≤9000 square millimeters. This area limit can ensure that the aluminum liquid has an appropriate flow rate during the pouring process, help reduce the turbulence of the aluminum liquid, avoid casting defects such as cold shuts and pores, and thus improve product quality and casting efficiency. Setting the ingate area ≤9000 square millimeters can balance the flow rate of the aluminum liquid and the filling effect, ensuring that the aluminum liquid can flow smoothly when entering the mold and fully fill each small structural part, thereby improving the stability and operability of the overall casting system.

[0017] Optionally, the area of ​​the biscuit is S1, the area of ​​the runner is S2, and the area of ​​the ingates is S3. The relationship between S1, S2 and S3 is: S1 = (4-6) S2, S2 = (1-2) S3. First, the area of ​​the biscuit S1 refers to the initial feeding area of ​​the aluminum liquid during the entire casting process. The relationship between the area S1 and the area of ​​the runner S2 is S1 = (4-6) S2, indicating that the area of ​​the biscuit is usually 4 to 6 times the area of ​​the runner. This design can ensure the uniform inflow of aluminum liquid and fully cover the entire mold area during the filling process. Next, the relationship between the area of ​​the runner S2 and the area of ​​the ingates S3 is S2 = (1-2) S3, indicating that the area of ​​the runner is equivalent to 1 to 2 times the area of ​​the ingates. This design prevents the flow rate of aluminum liquid flowing into the ingates from being too large, avoiding uneven filling of aluminum liquid caused by excessive flow rate of the ingates. Through reasonable area ratio design, not only the uniformity of mold filling is improved, but also the casting defects can be effectively reduced and the overall quality of the molded casting can be improved.

[0018] Optionally, the volume of the slag ladle is 5% to 10% of the total weight of the product. The slag ladle is a key component used to capture impurities, scale and gas during the pouring of aluminum liquid, which can effectively prevent these impurities from entering the casting, thereby improving the purity and quality of the casting. According to actual casting experience, the volume of the slag ladle is closely related to the quality of the aluminum liquid. If the volume of the slag ladle is too small, it may not be able to fully capture impurities in the aluminum liquid, resulting in a decrease in the quality of the casting; if it is too large, it may affect the fluidity of the aluminum liquid and even cause cold shut defects during the pouring process. Setting the slag ladle volume to 5% to 10% of the product weight helps to optimize the flow state of the aluminum liquid and the impurity capture effect, ensure the stability of the aluminum liquid when filling the mold, and effectively control the quality of the aluminum liquid. Through this design, it can ensure that the quality of the aluminum liquid meets the requirements during the casting process, reduce the later finishing work, and improve production efficiency and product quality.

[0019] An embodiment of the present invention also provides a casting method, which uses the double-shot integrated battery shell casting system as described above for casting, forming symmetrical filling of the integrated rear body. During filling, two streams of aluminum liquid instantly impact and offset each other, causing the aluminum liquid to fuse.

[0020] Optionally, the molten aluminum first enters the edge of the wheel arch flange to preferentially fill the edge of the wheel arch; and then the molten aluminum enters the rear body from the edge of the rear body wheel arch to fill the integrated rear body.

[0021] Optionally, the overall filling time of the product is ≤70ms.

[0022] One or more technical solutions provided in the embodiments of the present invention have at least the following technical effects or advantages:

[0023] The pouring system has two runner systems, which can greatly improve the elongation performance of the product at the wheel cover and the connection between the end and the front floor, and greatly improve the qualification rate of the spr connection point of the product. The molten aluminum enters the cross runner from the material cake, accelerates the flow through the cross runner and finally enters the inner gate of the battery shell. Due to the design of the cross runner and the conformal arrangement of the inner gate, the molten aluminum can efficiently and evenly fill the entire battery shell, especially in the wheel cover and the end, significantly improving the elongation and mechanical properties of these areas. Through this innovative pouring system, defects such as cold shut flow marks and cracks during the filling process are significantly reduced, improving the quality and reliability of the product.

[0024] During pouring, the pouring system forms a symmetrical filling for the integrated rear body, which greatly expands the die-casting process window, reduces the debugging difficulty of on-site process personnel, and greatly shortens the distance from the inner gate to the edge of the battery shell. At the same time, after filling, the two streams of molten aluminum instantly impact and collide with each other, generating a large impact energy, which effectively causes the molten aluminum to fuse, reduces aluminum liquid defects, and greatly improves the mechanical properties of the product, especially the tensile strength and elongation performance of the parts that need to be supported at both ends of the battery shell, thereby greatly reducing the risk of cracking at the bolt support parts.

[0025] Advantages of additional aspects of the present invention will be given in the following description, and in part will become obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. In addition, the spacing or size between the components is exaggerated to show the positions of the components, and the schematic diagram is only used for illustration.

[0027] Figure 1 It is a schematic diagram of the single-side pouring of the existing one-piece rear body;

[0028] Figure 2 It is a schematic diagram of the existing one-piece rear body single-side center pouring;

[0029] Figure 3 It is a schematic diagram of a dual-shot integrated battery shell pouring system provided by an embodiment of the present invention;

[0030] Figure 4 is a top view of a dual-shot integrated battery shell pouring system provided by an embodiment of the present invention;

[0031] Figure 5 is a schematic diagram of installation points provided by an embodiment of the present invention;

[0032] In the figure: 1. First material cake; 2. Second material cake; 3. First horizontal runner; 4. Second horizontal runner; 5. Battery shell; 6. Slag bag; 7. Ingate; 8. Wheel cover; 9. Single-side pouring; 10. Mounting point; DETAILED DESCRIPTION

[0033] It should be noted that the following detailed descriptions are illustrative and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those of ordinary skill in the art to which the present invention belongs. In addition, it should also be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0034] Example 1

[0035] In order to solve the technical problems mentioned in the background technology, this embodiment proposes a one-mold-one-cavity integrated battery shell pouring system produced by double injection positions, such as Figure 3 , Figure 4 , Figure 5 As shown, the pouring system has two sets of runner systems, which can greatly improve the elongation performance of the product at the wheel cover 8 and the connection between the end and the front floor, and greatly improve the qualified rate of the product's SPR connection points.

[0036] The pouring system includes:

[0037] First cake 1: The cake thickness is about 30±5mm, and the diameter is ≥220mm. This size can greatly improve the gate ratio of the pouring system, increase the thickness of the inner gate during die casting, and prevent the cake from bursting during the production process. The second cake 2 has the same design as the first cake 1.

[0038] The first runner 3: The runner goes upward in the opposite direction of gravity, and the cross-sectional area gradually decreases, and then it is divided into two branches. The cross-sectional areas of the two runners gradually decrease, so as to improve the acceleration effect of the aluminum liquid in the runner. Each branch runner is divided into six inner gates, and the aluminum liquid can enter the edge of the wheel cover flange first, forming a priority filling of the wheel cover edge.

[0039] Compared with the traditional center-injection and single-side-injection wheel cover, the filling end of this pouring system becomes the filling starting position, thereby reducing the risk of insufficient filling. In addition, the edge of the wheel cover is close to the gate, which can obtain sufficient boosting capacity, and the density of the wheel cover edge is higher, which can reduce the risk of defects at the edge of the product wheel cover, thereby improving the mechanical properties of the product. The aluminum liquid then enters the rear body from the edge of the rear body wheel cover to fill the integrated rear body, and the filling distance is also close. The second runner 4 has the same function as the first runner 3, and the double runner filling increases the area of ​​the inner gate.

[0040] The inner gate 7 is designed in a completely conformal manner, and the entire gate is arranged completely according to the edge shape of the battery shell 5, which not only greatly increases the filling area of ​​the inner gate, but also directly fills the mounting points 10 at both ends of the battery shell at a close distance, effectively improving the elongation, tensile strength and other mechanical properties of both sides of the battery shell, and greatly reducing the risk of cracking at the mounting point 10.

[0041] The area of ​​the overall inner gate is ≤9000 square millimeters, the aluminum liquid flow rate is about twice that of the original product, and the overall filling time of the product is ≤70ms. During the filling process, the temperature of the aluminum liquid decreases slightly, and the risk of defects such as cold shut flow marks in the product is greatly reduced.

[0042] The relationship between the cake area S1, the runner area S2, and the inner gate area S3 is as follows: S1 = (4-6) S2, S2 = (1-2) S3, which can ensure the acceleration ratio of the aluminum alloy liquid during the filling process.

[0043] The slag bag 6 is located in the middle of the product, where the aluminum liquid converges. The volume of the slag bag is about 5% to 10% of the total weight of the product. It can effectively collect the aluminum liquid temperature at the end of the product to reduce the relatively low temperature of the product.

[0044] The integrated battery shell adopts a double-shot pouring system, which adopts a completely symmetrical pouring system to form a symmetrical filling for the integrated rear body. Compared with the traditional single-sided filling method with a filling time of ≥100ms, the double-shot filling time in this embodiment can be shortened to ≤70ms, which greatly expands the die-casting process window and reduces the debugging difficulty of on-site process personnel. According to the relationship (functional relationship) between force (F) and work (W), as shown below: W=F*S, where S is the flow distance of the aluminum liquid, the energy required for each part of the aluminum liquid to fill each place is Wn, and the total energy required for the entire product to be filled is Fn. The overall work Wn is the integral of the force Fn and the distance Sn, as shown in the following integral formula: Wn=F1*S1+F2*S2+……+Fn*Sn

[0045] The above formula can be equivalent to the following integral formula: Wn = ∫Fndx*∫Sndy. According to the above formula, under the premise that the overall quality of the product remains unchanged, the distance is shortened and the energy of product filling is reduced.

[0046] In addition, the entire gate is laid out along the outer contour of the battery shell and adopts a conformal gate to form a completely symmetrical structure, which can greatly shorten the distance from the inner gate to the edge of the battery shell. At the same time, after filling, the two streams of aluminum liquid instantly impact and hedge, generating a large impact energy, effectively fusing the aluminum liquid, reducing aluminum liquid defects, and greatly improving the mechanical properties of the product, especially the tensile strength and elongation performance of the parts that need to be supported at both ends of the battery shell, thereby greatly reducing the risk of cracking at the bolt support part. Compared with single-shot production, double-shot production is adopted, and the installation points at both ends are near the gate side, the filling distance is short, and the filling distance on both sides is consistent, which can ensure the consistency of the performance of the installation points at both ends of the product and ensure the stability of the product's qualified rate.

[0047] Embodiment 2:

[0048] The dual-shot integrated battery shell pouring system as described in Example 1 is used for pouring, and the filling of the integrated rear body is symmetrically filled. During the filling, the two streams of aluminum liquid instantly impact and hedge, so that the aluminum liquid fuses. In this method, the aluminum liquid enters the mold through the designed cross runner and inner gate, and is injected simultaneously from two directions near the key position of the mold, producing an instantaneous impact. The hedging effect of the two streams of aluminum liquid allows the aluminum liquid to merge quickly in a short time, ensuring that the aluminum liquid can evenly fill all parts of the mold and reduce casting defects such as cold shut and pores that may occur during the filling process. This casting method can effectively improve the filling efficiency of aluminum liquid in the mold, reduce the pouring time, and at the same time reduce the gas or impurities that may be brought into the aluminum liquid during the flow process through the hedging effect, thereby improving the quality and stability of the casting.

[0049] The molten aluminum first enters the edge of the wheel cover flange and fills the edge of the wheel cover first; then the molten aluminum enters the rear body from the edge of the wheel cover to fill the one-piece rear body. By designing the molten aluminum to enter the edge of the wheel cover flange first, it can ensure that the key areas of the wheel cover are fully filled during the initial pouring process to avoid defects such as thin walls and pores. Subsequently, the molten aluminum enters other areas of the rear body from the edge of the wheel cover to complete the filling of the entire one-piece rear body. This priority filling design can ensure the casting quality of each part of the body, especially the structural strength and stability of the wheel cover flange.

[0050] Although the above describes the specific implementation mode of the present invention in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art on the basis of the technical solution of the present invention without creative work are still within the scope of protection of the present invention.

Claims

1. A dual-shot integrated battery shell pouring system, characterized in that: include: Casting structures and slag bags; The casting structure is symmetrically arranged on both sides of the wheel cover of the battery shell, and the casting structure includes a material cake and a cross runner. The cross runner is upward in the opposite direction of gravity, and the cross-sectional area of ​​the cross runner gradually decreases. One end of the cross runner is connected to the material cake, and the other end of the cross runner is connected to the battery shell to form an inner gate, and the inner gate is arranged according to the edge shape of the battery shell; the slag bag is located at the edge of the middle part of the battery shell.

2. The dual-shot integrated battery shell pouring system according to claim 1, characterized in that: The material cake is a disc-shaped structure, the thickness of the material cake is 30±5mm, and the diameter of the material cake is ≥220mm.

3. The dual-shot integrated battery shell pouring system according to claim 1, characterized in that: The runner is divided into a plurality of branch runners, and each branch runner is divided into a plurality of ingates.

4. The dual-shot integrated battery shell pouring system according to claim 3, characterized in that: The runner is divided into two branch runners, and each branch runner is divided into 6 inner gates.

5. The dual-shot integrated battery shell pouring system according to claim 1, characterized in that: The area of ​​the overall gate is ≤9000 square millimeters.

6. The dual-shot integrated battery shell pouring system according to claim 1, characterized in that: The area of ​​the cake is S1, the area of ​​the runner is S2, the area of ​​the inner gate is S3, and the relationship between S1, S2 and S3 is: S1 = (4-6) S2, S2 = (1-2) S3.

7. The dual-shot integrated battery shell pouring system according to claim 1, characterized in that: The volume of the slag bag is 5% to 10% of the total weight of the product.

8. A casting method, characterized in that: The dual-shot integrated battery shell pouring system as described in any one of claims 1 to 7 is used for pouring, so that the integrated rear body is filled symmetrically. During the filling, two streams of aluminum liquid instantly impact and offset each other, causing the aluminum liquid to fuse.

9. The pouring method according to claim 8, characterized in that The molten aluminum first enters the edge of the wheel arch flange and fills the edge of the wheel arch first; then the molten aluminum enters the rear body from the edge of the rear body wheel arch and fills the integrated rear body.

10. The pouring method according to claim 8, characterized in that: The overall filling time of the product is ≤70ms.

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