Lower automobile body die-casting structure and automobile
By designing the connection method of hollowed-out area and nesting in the die-casting structure of the lower body, the high cost and low efficiency problems caused by waste of space and separate open molding die-casting in the hollow-out design of the lower body are solved, and the material utilization rate and manufacturing efficiency are improved.
Patent Information
- Application Number
- CN202420881797.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-04-25
- Publication Date
- 2025-04-25
- Estimated Expiration
- 2034-04-25
AI Technical Summary
In automotive lightweight design, the hollow design of the lower body is wasted in the die-casting process, and each component is individually opened and die-cast, resulting in high manufacturing costs and low manufacturing efficiency.
A die-cast structure for the lower body is adopted, including the main body part, the first nesting and the second nesting. Through the design of the hollow area and the connection of the nesting, the simultaneous manufacturing of the lower body and other components is realized, reducing the number of molds and improving manufacturing efficiency.
It improves the material utilization rate of the die-cast structure of the lower body, reduces the cost of mold development and production, improves manufacturing efficiency, and ensures the mechanical properties of the die-cast products.
Smart Images
Figure CN222793658U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of automobile technology, and in particular to a lower body die-casting structure and an automobile. Background Art
[0002] In the related art, based on the demand for lightweight design of automobiles, the car body can be manufactured by die casting, for example, the lower body is manufactured by die casting. For electric vehicles using cell to body integration technology (CTB), the body floor and the upper shell of the battery pack are combined into one, and the flat sealing surface formed by the upper cover of the battery, the door sill and the front and rear cross beams is integrated to seal the passenger compartment through sealant, and the bottom is assembled with the battery through the mounting point. That is, the floor of the lower body adopts a hollow design for installing the upper cover of the battery. Since the bottom plate of the lower body is hollow, there is a waste of space in the die casting process. At the same time, in order to further realize the lightweight design of the automobile, other components in the lower body, such as the front subframe, the rear subframe control arm and other components, also need to be manufactured by die casting. However, each component is die-casted separately, which will lead to increased manufacturing costs and low manufacturing efficiency. Utility Model Content
[0003] In order to solve at least one of the above technical problems, the present application provides a lower body die-casting structure, which can improve manufacturing efficiency and reduce die-casting costs. The technical solution adopted is as follows.
[0004] In the first aspect, the present application provides a lower body die-casting structure, including a main body, a first nested piece, and a second nested piece. The main body is provided with a hollow area, the edge of the hollow area includes a thin-walled part and a thick-walled part, and the thickness of the thin-walled part is less than the thickness of the thick-walled part; the first nested piece is arranged in the hollow area, the first nested piece includes a thin-walled area and a thick-walled area, and the thin-walled area of the first nested piece is connected to the thin-walled part through a first connecting part; the second nested piece is arranged in the hollow area, the second nested piece includes a thin-walled area and a thick-walled area, the thick-walled area of the second nested piece is connected to the thick-walled part through a second connecting part, and the second nested piece is also connected to the first nested piece through a third connecting part, and the second connecting part is spaced apart from the third connecting part; the first nested piece and the main body can be cut and separated, and the second nested piece and the main body and the first nested piece can be cut and separated.
[0005] In certain embodiments of the present application, the main body portion includes a front crossbeam, the front crossbeam is provided with a central channel, at least a portion of the central channel is formed in the thin-walled portion, and the first connecting portion is connected to the central channel.
[0006] In some embodiments of the present application, the third connecting portion connects the thin-walled region of the first nested piece and the thin-walled region of the second nested piece.
[0007] In certain embodiments of the present application, the main body portion includes two threshold beams arranged opposite to each other, the two threshold beams respectively forming edges on opposite sides of the hollow area, and the two threshold beams form at least a portion of the thick-walled portion, and the two ends of the second nested piece are respectively connected to the two threshold beams through a second connecting portion.
[0008] In certain embodiments of the present application, two ends of the first nested component are also respectively connected to the two threshold beams through a fourth connecting portion, the fourth connecting portion and the first connecting portion are spaced apart on the first nested component, and the fourth connecting portion and the second connecting portion are spaced apart on the main body.
[0009] In certain embodiments of the present application, the fourth connection portion includes a connection bridge, and a width of the connection bridge gradually decreases from the threshold beam to the first nesting member.
[0010] In certain embodiments of the present application, a thickness difference between the fourth connecting portion and a connection point of the first nested component is D4, and D4≤5 mm.
[0011] In some embodiments of the present application, the thickness difference between the first connecting portion and the first nested member at the connection point is D1, D1≤5mm; and / or
[0012] The thickness difference between the third connecting portion and the second nested member at the connecting portion is D2, D2≤5mm; and / or
[0013] The thickness difference between the second nested component and the first nested component at the connection point is D3, and D3≤5mm.
[0014] In some embodiments of the present application, the first nested member includes a front subframe, and the second nested member includes a rear subframe.
[0015] In a second aspect, the present application provides an automobile, comprising a lower body, wherein the lower body is obtained by cutting the first nested part and the second nested part from the lower body die-casting structure provided in the first aspect.
[0016] The embodiments of the present application have at least the following beneficial effects: the lower body and other components can be manufactured at the same time, which can improve the material utilization rate of the die-cast structure of the lower body, reduce the number of molds corresponding to the first nested parts and the second nested parts, save the cost of mold development, product die-casting, transportation and management, and improve manufacturing efficiency. By setting the thick-walled area to connect with the thick-walled part and the thin-walled area to connect with the thin-walled part, the thickness difference between the lower body and the nested parts can be reduced, so that the thickness of the connection part between the nested parts and the lower body is roughly the same. In the die-casting process, it is beneficial to improve the condensation of the molten metal after filling, ensure the fluidity and temperature of the molten metal, reduce the shrinkage and stress during the cooling process, ensure the mechanical properties of the die-casting product, and improve the manufacturing yield. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The aspects and advantages described and / or attached in the embodiments of the present application will become apparent and easy to understand in conjunction with the following drawings. It should be noted that the embodiments embodied in the following drawings are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application.
[0018] Figure 1 A schematic diagram of the die-cast structure of the lower vehicle body provided in an embodiment of the present application;
[0019] Figure 2 for Figure 1 AA section view;
[0020] Figure 3 for Figure 1 BB cross-section diagram;
[0021] Figure 4 A schematic diagram of the structure of the lower vehicle body provided in an embodiment of the present application;
[0022] Figure 5 A schematic diagram of the structure of the front subframe provided in an embodiment of the present application;
[0023] Figure 6 A schematic structural diagram of the rear subframe provided in an embodiment of the present application.
[0024] 1. The lower body is provided with a die-cast structure; 2. The main body is provided with a hollow area; 3. The front cross beam is provided with a central channel; 4. The door sill beam is provided with a central channel; 5. The door sill beam is provided with a central channel; 6. The rear cross beam is provided with a central channel; 7. The door sill beam is provided with a central channel; 8. The rear cross beam is provided with a central channel; 9. The rear cross beam is provided with a central channel; 10. The first nested part is provided with a first connecting part; 11. The fourth connecting part is provided with a central channel; 12. The door sill beam is provided with a central channel; 13. The door sill beam is provided with a central channel; 14. The rear cross beam is provided with a central channel; 15. The first nested part is provided with a first connecting part; 16. The fourth connecting part is provided with a central channel; 17. The second nested part is DETAILED DESCRIPTION
[0025] Combine the following Figures 1 to 6Embodiments of the present application are described in detail, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application.
[0026] In the description of the present application, it should be understood that if the terms "center", "middle", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "axial", "radial", "circumferential" and the like appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present application, unless otherwise specified, "multiple" means two or more.
[0027] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.
[0028] First, see Figures 1 to 3The present application provides a lower body die-casting structure 100, including a main body 10, a first nested piece 20 and a second nested piece 30, the main body 10 is provided with a hollow area 11, the edge of the hollow area 11 includes a thin-walled portion and a thick-walled portion, and the thickness of the thin-walled portion is less than the thickness of the thick-walled portion; the first nested piece 20 is arranged in the hollow area 11, the first nested piece 20 includes a thin-walled area and a thick-walled area, and the thin-walled area of the first nested piece 20 is connected to the thin-walled portion through a first connecting portion 21; the second nested piece 30 is arranged in the hollow area 11, the second nested piece 30 includes a thin-walled area and a thick-walled area, the thick-walled area of the second nested piece 30 is connected to the thick-walled portion through a second connecting portion 31, and the second nested piece 30 is also connected to the first nested piece 20 through a third connecting portion 32, and the second connecting portion 31 and the third connecting portion 32 are arranged at intervals; the first nested piece 20 and the main body 10 can be cut and separated, and the second nested piece 30 and the main body 10 and the first nested piece 20 can be cut and separated. For electric vehicles using cell-to-body integration technology (CTB), the body floor and the upper shell of the battery pack are combined into one, and the flat sealing surface formed by the battery upper cover, the door sill and the front and rear cross beams 14 is integrated to seal the passenger compartment through sealant, and the bottom is assembled with the battery through the mounting point. Therefore, for the lower body 200 of the CTB car, its floor adopts a hollow design, and the hollow area 11 is used to install the battery upper cover. When manufacturing the lower body 200, the hollow area 11 is used to simultaneously manufacture the first nested part 20 and the second nested part 30. After die-casting, the first nested part 20 and the second nested part 30 are cut and separated to obtain the lower body 200 with the hollow area 11 and the corresponding parts of the first nested part 20 and the second nested part 30. In this way, the lower body 200 and other parts can be manufactured at the same time, which can improve the material utilization rate of the lower body die-casting structure 100, reduce the number of molds corresponding to the first nested part 20 and the second nested part 30, save the cost of mold development, product die-casting, transportation and management, and improve manufacturing efficiency. Using the third connecting portion 32 to connect the second nested piece 30 to the first nested piece 20 can improve the stability of the two nested pieces in the hollow area 11. Before the two nested pieces are cut off, it helps to maintain the uniformity and balance of the forces on the two nested pieces in the hollow area 11, thereby improving the die-casting effect of the two nested pieces.
[0029] At the same time, due to the differences in volume, cross-sectional thickness and other factors between the first nested parts 20 and the second nested parts 30 and the edge of the hollow area 11, there may be stress concentration, shrinkage, undercasting, cold shut, cracks and other problems in the die-casting process. In order to overcome these problems, it is also necessary to consider the thickness of the connection between the first nested parts 20 and the second nested parts 30 and the edge of the hollow area 11. The present application considers that the thickness of the edge of the hollow area 11 of the lower body 200 has a thick-walled portion and a thin-walled portion. Correspondingly, the first nested part 20 and the second nested part 30 themselves also have a thick-walled area with a larger thickness and a thin-walled area with a smaller thickness. Therefore, by setting the thick-walled area of the first nested part 20 and the second nested part 30 to be connected to the thick-walled portion, and setting the thin-walled area of the first nested part 20 and the second nested part 30 to be connected to the thin-walled portion, the thickness difference between the lower body 200 and the nested part can be reduced, so that the thickness of the connecting part between the nested part and the lower body 200 is roughly the same. In the die-casting process, it is beneficial to enhance the coagulation of the molten metal (such as aluminum liquid, aluminum alloy liquid) after filling, ensure the fluidity and temperature of the molten metal, reduce the shrinkage and stress in the cooling process, solve the problems of stress concentration, shrinkage of castings, undercasting, etc. in the die-casting process, ensure the mechanical properties of the die-casting product (lower body 200, first nested part 20, second nested part 30), and improve the manufacturing yield.
[0030] For example, see Figures 4 to 6 The first nested part 20 may be a front subframe 201, and the second nested part 30 may be a rear subframe 202, or a rear subframe control arm. Of course, the first nested part 20 and the second nested part 30 may also be other die-casting parts of the automobile such as a battery anti-collision beam. The hollow area 11 may be set in the front floor area of the lower body 200.
[0031] In some embodiments, the main body 10 includes a front cross beam 12, and the front cross beam 12 is provided with a central channel 121, at least a portion of the central channel 121 is formed in a thin-walled portion, and the first connecting portion 21 is connected to the central channel 121. Since the thickness of the central channel 121 is smaller than the design thickness of other parts of the front cross beam 12, the central channel 121 forms a portion of a thin-walled portion, and the thin-walled portion is used to connect with the thin-walled area of the first nested piece 20, which can reduce the thickness difference between the two, so that the mechanical properties of the central channel 121 and the first nested piece 20 at the connection are consistent, which is conducive to ensuring that the two can be well formed during the die-casting process and improving the die-casting effect. Exemplarily, the first connecting portion 21 can be formed by a portion of the central channel 121 extending to the hollow area 11, or a portion of the first nested piece 20 extending outward from the thin-walled area, or a connecting bridge set between the first nested piece 20 and the central channel 121. When the first nested piece 20 is cut, the first connecting portion 21 may be retained to form a portion of the central channel 121 , or to form a portion of the front subframe 201 , or the first connecting portion 21 may be cut off, which is not limited here.
[0032] In some embodiments, the third connection part 32 connects the thin-walled area of the first nested part 20 and the thin-walled area of the second nested part 30. The third connection part 32 is used to connect the thin-walled areas of the first nested part 20 and the second nested part 30, respectively, so that the thickness of the entire third connection part 32 can be roughly consistent, and the thickness difference between the first nested part 20, the second nested part 30 and the third connection part 32 is reduced, so that the force of the two nested parts at the connection part is more uniform, which helps to avoid the stress concentration problem during the die-casting process and improve the die-casting effect. Optionally, the third connection part 32 can be connected to the first nested part 20 and the second nested part 30 in the form of a connecting bridge, or in other examples, the thin-walled area of the second nested part 30 can be arranged toward the thin-walled area of the first nested part 20 to shorten the length of the connecting bridge. Alternatively, the thin-walled area of the second nested part 30 and the thin-walled area of the first nested part 20 are directly connected, and the connecting part forms the third connection part 32, which is not limited here.
[0033] In some embodiments, the main body 10 includes two threshold beams 13 arranged opposite to each other, the two threshold beams 13 respectively form the edges of the opposite sides of the hollow area 11, and the two threshold beams 13 are formed as at least a portion of thick-walled portions, and the two ends of the second nested piece 30 are respectively connected to the two threshold beams 13 through the second connecting portions 31. By connecting the two ends of the second nested piece 30 to the two threshold beams 13 respectively, the connection strength of the second nested piece 30 with the main body 10 can be improved, and the connection stability of the second nested piece 30 with the main body 10 can be improved, and the stability of the second nested piece 30 can be improved. Generally, the thickness of the threshold beam 13 is greater than the thickness of the central channel 121 of the front cross beam 12, so connecting the two ends of the second nested piece 30 with a larger thickness to the threshold beam 13 can reduce the thickness difference between the two and improve the casting effect. Optionally, the third connection portion 32 may be located on the perpendicular bisector of the line connecting the two ends of the second nested piece 30, so that the line connecting the connection point of the second nested piece 30 with the third connection portion 32 and the connection points of the two second connection portions 31 is roughly in the shape of an isosceles triangle, further improving the stability of the second nested piece 30 connected to the main body 10. Exemplarily, the second connection portion 31 may also be provided in the form of a connecting bridge.
[0034] Optionally, the main body 10 further includes a rear cross beam 14, which is arranged opposite to the front cross beam 12 to form the edges of the front and rear sides of the hollow area 11. The front cross beam 12, the rear cross beam 14 and the two door sill beams 13 enclose the hollow area 11.
[0035] In some embodiments, the two ends of the first nested part 20 are also connected to the two door sill beams 13 respectively through the fourth connection part 22. The fourth connection part 22 and the first connection part 21 are arranged at intervals on the first nested part 20, and the fourth connection part 22 and the second connection part 31 are arranged at intervals on the main body 10. By setting the fourth connection part 22, the connection points between the first nested part 20 and the main body 10 can be increased, the connection stability of the first nested part 20 can be improved, and it is ensured that the first nested part 20 and the lower body 200 can be well formed during the die casting process. The first connection part 21 and the fourth connection part 22 are arranged at intervals on the first nested part 20, which can ensure that the two connection parts do not interfere with each other. The fourth connection part 22 and the second connection part 31 are arranged at intervals on the main body 10, which can also ensure that the two are arranged independently. Exemplarily, the fourth connection part 22 is connected to the thick wall area of the first nested part 20 to reduce the thickness difference between the two and improve the die casting effect.
[0036] In some embodiments, the fourth connection portion 22 includes a connection bridge, and the width of the connection bridge gradually decreases from the door sill beam 13 to the first nested member 20. In this way, it is possible to ensure that there is a sufficient connection area between the connection bridge and the door sill beam 13 and improve the connection strength of the first nested member 20. The gradually decreasing width of the connection bridge can also make the width of the connection between the connection bridge and the first nested member 20 roughly equal, saving the material of the connection bridge while meeting the connection strength.
[0037] It can be understood that the thin-walled portion and the thick-walled portion of the edge of the hollow area 11 are relative. When the thickness of the edge of the hollow area 11 is not uniformly designed, thick-walled portions and thin-walled portions are generated accordingly. Similarly, the thin-walled area and the thick-walled area in the first nested part 20 and the second nested part 30 are also relative. According to the structural design of the first nested part 20 and the second nested part 30 themselves, there are areas with larger thickness and areas with smaller thickness. This example does not limit the absolute value of the thickness of the thin-walled area, the thick-walled area, the thin-walled portion, and the thick-walled portion. Similarly, in other examples, the thick-walled area of the first nested part 20 and the second nested part 30 is not limited to its two ends, but can also be other parts. For the first nested part 20 and the second nested part 30, the division of its thick-walled area and thin-walled area is related to the structural design of the specific components of the first nested part 20 and the second nested part 30, and this example does not limit it. The thick-walled areas of the first nested piece 20 and the second nested piece 30 are arranged toward the door sill beam 13 , which can reduce the thickness difference at the connection between the first nested piece 20 , the second nested piece 30 and the door sill beam 13 , thereby improving the die-casting effect.
[0038] In some embodiments, the thickness difference between the fourth connection portion 22 and the first nested member 20 is D4, D4 ≤ 5 mm, for example, D4 is 5 mm, 4 mm, 3 mm, 1 mm, etc., or the thicknesses of the two are the same. By controlling the thickness difference between the fourth connection portion 22 and the first nested member 20, it is helpful to condense the molten metal during the die casting filling process, prevent shrinkage and cracks caused by stress concentration, avoid undercasting, cold shut and other phenomena, and improve the die casting effect.
[0039] In some embodiments, the thickness difference between the first connection part 21 and the first nested part 20 is D1, D1≤5mm, the thickness difference between the third connection part 32 and the second nested part 30 is D2, D2≤5mm, and the thickness difference between the second nested part 30 and the first nested part 20 is D3, D3≤5mm. Similarly, D1, D2, and D3 can be 5mm, 4mm, 3mm, 1mm, etc., or zero, that is, the thickness of the two interconnected parts is the same. By controlling the thickness difference between the first connection part 21 and the first nested part 20, the thickness difference between the third connection part 32 and the second nested part 30, and the thickness difference between the second nested part 30 and the first nested part 20, it is helpful to condense the metal liquid during the die casting filling process, prevent shrinkage and cracks caused by stress concentration, avoid undercasting, cold shut and other phenomena, and improve the die casting effect.
[0040] Optionally, the raw material used for die casting can be aluminum liquid, aluminum alloy liquid or other alloy metal liquid, which can be flexibly set according to the material design of the lower body 200 and the first nested part 20 and the second nested part 30, and is not limited here. For example, when the metal liquid is a zinc alloy, the thickness difference at the connection can be controlled at 1 to 3 mm, when the metal liquid is an aluminum-magnesium alloy, the thickness difference at the connection can be 1.5 to 4 mm, and when the metal liquid is a copper alloy, the thickness difference at the connection can be 2 to 4 mm.
[0041] Second, see Figure 4 The present application also provides a car, which includes a lower body 200, and the lower body 200 is obtained by cutting a first nested part 20 and a second nested part 30 from the lower body die-casting structure 100 provided in the first aspect.
[0042] In the description of this specification, if the reference terms "one embodiment", "some examples", "some embodiments", "illustrative embodiment", "example", "specific example", or "some examples" appear, it means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.
[0043] The above describes the implementation methods of the present application in detail in conjunction with the accompanying drawings, but the present application is not limited to the above implementation methods. Various changes can be made within the knowledge scope of ordinary technicians in the technical field without departing from the purpose of the present application.
[0044] In the description of this application, if "," appears in the patent name, it means an "and" relationship, not an "or" relationship. For example, if the patent name is "a kind of A, B", it means that the content required to be protected by this application is: the technical solution with the subject name A and the technical solution with the subject name B.
Claims
1. A lower body die-casting structure, characterized in that: include A main body, wherein the main body is provided with a hollow area, an edge of the hollow area includes a thin-walled portion and a thick-walled portion, and the thickness of the thin-walled portion is less than the thickness of the thick-walled portion; A first nested piece is arranged in the hollow area, the first nested piece includes a thin-walled area and a thick-walled area, and the thin-walled area of the first nested piece is connected to the thin-walled part through a first connecting part; A second nested piece is arranged in the hollow area, the second nested piece includes a thin-walled area and a thick-walled area, the thick-walled area of the second nested piece is connected to the thick-walled area via a second connecting portion, and the second nested piece is also connected to the first nested piece via a third connecting portion, and the second connecting portion is spaced apart from the third connecting portion; The first nesting piece and the main body can be cut and separated, and the second nesting piece, the main body and the first nesting piece can be cut and separated.
2. The lower body die-casting structure according to claim 1, characterized in that: The main body portion includes a front cross beam, the front cross beam is provided with a central channel, at least a portion of the central channel is formed in the thin-walled portion, and the first connecting portion is connected to the central channel.
3. The lower vehicle body die-casting structure according to claim 1, characterized in that: The third connection portion connects the thin-walled region of the first nested piece and the thin-walled region of the second nested piece.
4. The lower body die-casting structure according to claim 1, characterized in that: The main body includes two threshold beams arranged opposite to each other, the two threshold beams respectively form edges on opposite sides of the hollow area, and the two threshold beams form at least a portion of the thick-walled portion, and the two ends of the second nested piece are respectively connected to the two threshold beams through second connecting parts.
5. The lower vehicle body die-casting structure according to claim 4, characterized in that: Both ends of the first nesting member are also connected to the two door sill beams respectively through fourth connecting parts. The fourth connecting part and the first connecting part are spaced apart on the first nesting member, and the fourth connecting part and the second connecting part are spaced apart on the main body.
6. The lower vehicle body die-casting structure according to claim 5, characterized in that: The fourth connection portion includes a connection bridge, and the width of the connection bridge gradually decreases from the threshold beam to the first nesting member.
7. The lower vehicle body die-casting structure according to claim 5, characterized in that: The thickness difference between the fourth connecting portion and the connecting portion of the first nested component is D4, and D4≤5mm.
8. The lower vehicle body die-casting structure according to any one of claims 1 to 7, characterized in that: The thickness difference between the first connecting portion and the first nested member at the connection point is D1, D1≤5mm; and / or The thickness difference between the third connecting portion and the second nested member at the connecting portion is D2, D2≤5mm; and / or The thickness difference between the second nested component and the first nested component at the connection point is D3, and D3≤5mm.
9. The lower vehicle body die-casting structure according to any one of claims 1 to 7, characterized in that: The first nest includes a front subframe and the second nest includes a rear subframe.
10. An automobile, characterized in that: It comprises a lower body, which is obtained by cutting the first nesting part and the second nesting part from the lower body die-casting structure according to any one of claims 1 to 9.