Anti-collision beam, vehicle door assembly, vehicle and vehicle door manufacturing method

Abstract

The invention relates to an anti-collision beam, a vehicle door assembly, a vehicle and a vehicle door manufacturing method.The anti-collision beam is a variable-cross-section beam body, the variable-cross-section beam body is of a hollow structure and comprises connecting ends arranged at the two ends of the variable-cross-section beam body, and the connecting ends are used for being connected with a mounting support; a plurality of concave parts which are concave towards the inner side and a plurality of convex parts which are convex towards the outer side are alternately formed on the peripheral surface of the connecting end, and the adjacent concave parts and convex parts are in smooth transition connection. The anti-collision beam is a variable cross-section beam body and can be adjusted in a customized mode according to the complex space structure in the vehicle door assembly; a plurality of concave parts and a plurality of convex parts are alternately formed on the peripheral surface of the connecting end used for being connected with the mounting bracket, so that an uneven connecting surface can be formed on the peripheral surface of the connecting end, and when the connecting end is embedded or integrally formed with the mounting bracket, the contact area between the connecting end and the mounting bracket can be increased; and the circumferential firmness and stability of the connection between the end part of the anti-collision beam and the mounting bracket are favorably improved.

Description

Technical Field

[0001] This application relates to the field of vehicle manufacturing technology, specifically to a crash beam, a door assembly, a vehicle, and a method for manufacturing doors. Background Technology

[0002] With increasingly stringent automotive safety regulations, door anti-collision beams, as key components for side-impact safety, are facing ever-higher requirements for structural strength and lightweight design.

[0003] Traditional crash beams are typically made by stamping and welding multiple layers of steel plates. While they have a certain strength, they are heavy and require welding to connect them to the mounting brackets on the inner door panel, resulting in complex processes and low production efficiency.

[0004] Furthermore, the welded joints at both ends of the crash beam are prone to stress concentration, affecting the overall structural strength and durability. If the connection between the crash beam end and the mounting bracket is achieved through embedding or integral molding, the poor stability of the connection between the crash beam end and the mounting bracket can lead to loosening or detachment, thus affecting the overall structural stability and durability. Summary of the Invention

[0005] One objective of this application is to provide a crash beam to solve the technical problem of poor stability and durability when connecting crash beams and mounting brackets in the prior art; a second objective is to provide a door assembly; a third objective is to provide a vehicle; and a fourth objective is to provide a door manufacturing method.

[0006] To achieve the above objectives, the technical solution adopted in this application is as follows: A crash beam is a variable cross-section beam with a hollow structure, including connecting ends disposed at both ends of the variable cross-section beam, the connecting ends being used to connect to a mounting bracket; The outer peripheral surface of the connecting end is alternately formed with multiple recesses facing inward and multiple protrusions facing outward, and adjacent recesses and protrusions are smoothly connected.

[0007] Based on the aforementioned technical means, since the anti-collision beam is a variable cross-section beam, it can be customized according to the complex internal spatial structure of the door assembly. The cross-sectional shape and size of the anti-collision beam can be flexibly changed at different locations according to the layout of components such as the inner door panel, reinforcing plate, and window regulator, to adapt to the layout requirements of the door assembly and the entire vehicle. The variable cross-section beam has a hollow structure, ensuring that all sections are closed, resulting in excellent strength and resistance to bending and torsion, effectively improving side-impact performance. The anti-collision beam includes connecting ends at both ends of the variable cross-section beam. These connecting ends connect to mounting brackets. The outer circumferential surface of the connecting ends alternately forms multiple inward-facing recesses and multiple outward-facing protrusions, creating an uneven connecting surface. When the connecting ends are embedded or integrally formed with the mounting brackets, the contact area between the connecting ends and the mounting brackets is increased, which helps improve the circumferential firmness and stability of the connection between the anti-collision beam ends and the mounting brackets.

[0008] Furthermore, the plurality of protrusions include a plurality of first protrusions and a plurality of second protrusions, wherein the maximum curvature of the first protrusions is greater than the maximum curvature of the second protrusions.

[0009] According to the aforementioned technical means, since the multiple protrusions include multiple first protrusions and multiple second protrusions, and the maximum curvature of the first protrusions is greater than that of the second protrusions, multiple protrusions with different curvatures can be formed on the outer peripheral surface of the connecting end. The larger curvature of the first protrusion allows for a deeper mechanical interlocking structure between the first protrusion and the mounting bracket. When integrally formed with the anti-collision beam via die casting or other methods, the molten metal can better encapsulate the first protrusion, forming a robust mechanical interlock. This interlocking structure effectively prevents the connecting end from separating from the mounting bracket when subjected to tensile or shear forces. The smaller curvature of the second protrusion provides a smoother contact surface, acting as a buffer and transition during stress transmission.

[0010] Furthermore, a straight portion is formed on the outer peripheral surface of the connecting end, and the straight portion smoothly transitions between two adjacent protrusions; Alternatively, the straight portion may smoothly transition between two adjacent recessed portions.

[0011] According to the aforementioned technical means, when the straight section smoothly transitions to an adjacent protrusion or recess, the stress transmission path on the outer circumference of the connection end can be altered. When the connection end is subjected to external force, the stress that might have been concentrated at the apex of the protrusion or the bottom of the recess will be dispersed to a wider area due to the presence of the straight section, avoiding structural damage caused by excessive local stress and improving the overall tensile strength of the connection end. Furthermore, the presence of the straight section provides a flat positioning surface for the connection between the end of the crash beam and the mounting bracket, facilitating accurate connection and fit between the connection end and the mounting bracket, thus improving the tightness and stability of the connection.

[0012] Furthermore, the cross-section of the connecting end is a first closed cross-section, and the first closed cross-section is a symmetrical cross-section.

[0013] Based on the aforementioned technical means, the connection end possesses excellent strength and resistance to bending and torsion due to its first closed section. The first closed section is symmetrical; when the connection end is connected to the mounting bracket and subjected to tension or compression, the symmetrical section ensures a relatively uniform stress distribution in the circumferential direction of the connection end, avoiding localized stress concentration. Under bending or torsional moments, the symmetrical section also guarantees a reasonable stress distribution at the connection end.

[0014] Furthermore, the shape of the first closed section is circular, rhomboid, elliptical, triangular, or trapezoidal.

[0015] Based on the aforementioned technical means, when the first closed section forms a circular cross-section by alternating multiple protrusions and recesses, the degree of unevenness on the outer circumferential surface is relatively small. This ensures that the strength and stiffness of each region in the circumferential direction of the connecting end are basically consistent. The near-circular cross-section is easy to process and manufacture, achieving a balance between mechanical properties and good manufacturability. When the first closed section forms a rhomboid cross-section by alternating multiple protrusions and recesses, the rhomboid cross-section has different mechanical properties in the two diagonal directions. The angle and side length of the rhomboid can be designed according to the actual stress conditions, giving the rhomboid cross-section high strength and stiffness in the main stress directions. In addition, the unique shape of the rhomboid cross-section can provide clear positioning features for installation. When the first closed section forms an elliptical cross-section by alternating multiple protrusions and recesses, the elliptical cross-section combines the characteristics of a circular and a long strip cross-section, exhibiting different mechanical properties in the two principal axis directions. The ratio of the major and minor axes of the ellipse can be adjusted according to the actual stress conditions, ensuring that the cross-section has sufficient strength and stiffness in the main stress directions while also meeting certain performance requirements in other directions. Meanwhile, when spatial constraints exist, an elliptical cross-section can be used to form a flat connection end to accommodate spatial constraints along the minor axis. When the first closed cross-section is connected by multiple protrusions, recesses, and straight sections to form a triangular cross-section, the triangular cross-section exhibits stability and maintains good shape stability under pressure, resulting in high strength and stiffness. When the first closed cross-section is connected by multiple protrusions, recesses, and straight sections to form a trapezoidal cross-section, the shape of the trapezoidal cross-section can be designed according to the actual stress conditions, allowing for a more rational distribution of material in the stress direction. This enables the trapezoidal cross-section to better adapt to load variations and improve the load-bearing capacity of the connection end. By adjusting the dimensions of the upper base, lower base, and height of the trapezoidal cross-section, the torsional resistance and connection stiffness of the connection end can be maximized, meeting the usage requirements under different working conditions.

[0016] Furthermore, the variable cross-section beam also has a main body segment located between the two connecting ends, and the outer peripheral surface of the main body segment includes multiple smoothly transitioned variable curvature surfaces.

[0017] Based on the aforementioned technical means, the outer periphery of the main body segment includes multiple smoothly connected variable curvature surfaces. These surfaces guide the direction of impact force transmission, allowing the impact force to be dispersed and transmitted along a predetermined path. By rationally designing the curvature changes of the surfaces and the smooth transition connections between them, the impact force can be evenly distributed within the main body segment, avoiding damage to the anti-collision beam structure caused by localized stress concentration.

[0018] Furthermore, the main body segment includes a first irregularly shaped segment, which is used to be disposed on the upper part of the door. The cross section of the first irregularly shaped segment is a second closed cross section, and the second closed cross section is a D-shaped cross section.

[0019] According to the above technical means, since the second closed section is a D-shaped section, it can avoid components such as the window lifting mechanism at the top of the car door, and provide the necessary torsional stiffness within the limited arrangement space.

[0020] Furthermore, the main body segment includes a second irregular segment, which is used to be disposed in the middle of the door. The cross section of the second irregular segment is a third closed cross section, which is a flat cross section.

[0021] Based on the aforementioned technical means, since the third closed section is a flat section, its shape allows it to form a large supporting plane in the middle of the door, providing stable rigid support for the inner door panel and related connecting components. When subjected to external loads, this flat section, through its unique geometry, can effectively disperse stress distribution, significantly improving the deformation resistance of the local structure, providing reinforced support for the central area of ​​the door, ensuring efficient load transfer, and enhancing the structural stability and overall rigidity of the door assembly.

[0022] Furthermore, the main body segment includes a third irregular segment, which is used to be installed at the lower part of the door. The cross-section of the third irregular segment is a fourth closed cross-section, which is a circular cross-section or a square cross-section.

[0023] Based on the above technical means, since the fourth closed section is a circular or square section, the radial dimension of the circumcircle of the fourth closed section can be maximized, thereby maximizing the bending strength and crushing energy absorption capacity of the third irregular section. This can more effectively resist the lateral bending force that the lower part of the door may suffer, maintain the stability of the structural shape, and provide reliable lateral support and main safety protection functions for the passenger compartment.

[0024] A door assembly includes the aforementioned anti-collision beam, a mounting bracket, and an inner door panel. The connecting end is inserted into the mounting bracket, and the anti-collision beam, the mounting bracket, and the inner door panel are an integral structure.

[0025] Based on the aforementioned technical means, the alternating recesses and protrusions on the outer circumference of the connecting end significantly increase the contact area between the anti-collision beam and the mounting bracket. Compared to traditional smooth surface connection methods, this special structure can better disperse stress when subjected to external forces.

[0026] Furthermore, there are multiple anti-collision beams, which are arranged sequentially along the height direction of the inner panel of the vehicle door, and adjacent anti-collision beams are arranged at an angle.

[0027] Based on the aforementioned technical means, since multiple anti-collision beams are sequentially arranged along the height direction of the inner door panel, they can effectively cover different height areas of the door. In a side collision, regardless of whether the impact point is located at the upper, middle, or lower part of the door, there are corresponding anti-collision beams to absorb and disperse the impact force, avoiding excessive local deformation of the door due to blind spots and providing more comprehensive protection for the passenger compartment. When two adjacent anti-collision beams are set at an angle, they, together with the inner door panel and other components, form a triangular support structure. Due to the stability of a triangle, this structure can significantly enhance the overall rigidity of the door. When subjected to lateral forces, the triangular support structure can effectively resist deformation, maintain the shape and structural integrity of the door, and prevent excessive inward or outward bulging of the door, thereby better protecting the passenger compartment space.

[0028] A vehicle comprising the aforementioned door assembly.

[0029] Based on the aforementioned technical methods, the reduced mass of the door assembly lowers the vehicle's unsprung mass (i.e., the mass not supported by springs in the suspension system). With reduced unsprung mass, the suspension system can respond more quickly and accurately to road surface changes, allowing the tires to better grip the ground, reducing wheel hop, and thus improving vehicle handling stability and agility. Furthermore, the reduced mass of the door assembly decreases the overall vehicle weight, requiring less power output from the engine and reducing fuel consumption. Simultaneously, the improved side-impact protection of the door assembly allows it to better absorb and disperse collision energy in the event of a side collision, reducing the impact force transmitted to the passenger compartment and protecting the occupants' survival space.

[0030] A method for manufacturing a vehicle door assembly includes the following steps: Closed tube blanks are prepared using high-strength steel plates; After heating the closed tube blank to the austenitizing temperature, it is placed in a hot gas expansion mold and formed into the variable cross-section beam of the anti-collision beam through a hot gas expansion forming process. The variable cross-section beam is then quenched in the hot gas expansion mold. The aluminum alloy raw material is heated to a state in which solid and liquid coexist, forming a semi-solid slurry. After the quenched variable cross-section beam is pre-placed in the die-casting mold, the mold is closed. Semi-solid slurry is injected into a die-casting mold to form an integrated structure of the inner door panel, mounting bracket, and anti-collision beam.

[0031] According to the above-mentioned technical means, when the door inner panel, mounting bracket and anti-collision beam are integrated by die casting process, the molten metal used to form the mounting bracket can cover the outer periphery of the connecting end, fill the recessed part and wrap the protruding part, so that the connecting end and the solidified mounting bracket form a mechanical interlocking structure. This mechanical interlocking structure changes the combination between the connecting end and the mounting bracket from simple surface adhesion to deep mechanical interlocking, which can effectively prevent the connection between the mounting bracket and the anti-collision beam from breaking or falling off.

[0032] Furthermore, the high-strength steel plate is a high-strength hot-formed steel plate with a tensile strength of 1500MPa~2000MPa, and the thickness of the high-strength steel plate is 1.5mm~3.0mm.

[0033] Based on the above technical means, it is possible to avoid the closed tube blank from bursting due to its small wall thickness during the subsequent hot gas expansion process, which would lead to cracks or openings in the variable cross-section beam. It is also possible to avoid the large heat capacity of the variable cross-section beam interfering with the metal fusion during the semi-solid die casting process, which would result in a decrease in the connection strength between the connection end of the anti-collision beam and the mounting bracket, as well as an increase in the weight of the anti-collision beam.

[0034] Furthermore, during the formation of the semi-solid slurry, the nascent solid particles are spheroidized by mechanical stirring.

[0035] Based on the aforementioned technical methods, mechanical stirring spheroidizes the primary solid particles, and the uniformly distributed spherical grains effectively hinder solute diffusion, resulting in a more homogeneous composition. Mechanical stirring, through the shear force generated by rotating blades or stirring rods, breaks down dendrites, increases the number of nucleation points, and refines the grain diameter. This is beneficial for forming dense aluminum alloy castings, significantly improving the material strength and toughness of the castings, and meeting vehicle safety and lightweight requirements.

[0036] Furthermore, during the process of injecting the semi-solid slurry into the die-casting mold, the injection pressure of the semi-solid slurry is 80MPa~150MPa.

[0037] According to the above technical means, the semi-solid slurry can be filled into every corner of the die-casting mold under high pressure injection, thereby achieving complete filling of the corresponding molding cavities of the inner door panel and each mounting bracket, and ensuring that the aluminum alloy mounting bracket and the outer peripheral surface of the end of the anti-collision beam are tightly bonded and rigidly connected after curing, thus forming an integrated molding structure of the inner door panel, mounting bracket and variable cross-section beam.

[0038] The beneficial effects of this application are: (1) In this application, the anti-collision beam is set as a variable cross-section beam, which can be customized according to the complex internal spatial structure of the door assembly. The cross-sectional shape and size of the anti-collision beam can be flexibly changed according to the layout of the door inner panel, reinforcing plate, window regulator and other components to adapt to the layout requirements of the door assembly and the whole vehicle.

[0039] (2) The alternating recesses and protrusions on the outer periphery of the connecting end in this application increase the contact area between the connecting end and the mounting bracket, allowing the shear force to be more evenly distributed on the connecting surface. Compared to the traditional smooth connecting surface, this uneven structure can effectively resist shear deformation and prevent relative sliding between the connecting end and the mounting bracket, thereby improving the shear resistance of the anti-collision beam during the collision process and ensuring that the anti-collision beam can stably perform its energy absorption and buffering functions. When the mounting bracket is integrally formed on the outer periphery of the connecting end by die casting, the molten metal fills the recesses and wraps the protrusions during the die casting process, forming a mechanical interlocking structure. This mechanical interlocking structure changes the connection between the connecting end and the mounting bracket from simple surface adhesion to deep mechanical interlocking, directly increasing the friction coefficient between the connecting end and the mounting bracket. During vehicle operation, vibration and impact can prevent the connection between the anti-collision beam and the mounting bracket from loosening. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of the anti-collision beam provided in an embodiment of this application; Figure 2 This is a schematic diagram of the structure of the door assembly provided in an embodiment of this application; Figure 3 This is a schematic diagram illustrating the connection between the connecting end and the mounting bracket provided in an embodiment of this application; Figure 4 The following are provided for the embodiments of this application: Figure 2 Section of AA Figure 1 ; Figure 5 The following are provided for the embodiments of this application: Figure 2 Section of AA Figure 2 ; Figure 6 The following are provided for the embodiments of this application: Figure 2 Section of AA Figure 3 ; Figure 7 The following are provided for the embodiments of this application: Figure 2 Section of AA Figure 4 ; Figure 8 The following are provided for the embodiments of this application: Figure 2 Section of AA Figure 5 ; Figure 9The following are provided for the embodiments of this application: Figure 2 Cross-sectional view of BB in the middle; Figure 10 The following are provided for the embodiments of this application: Figure 2 Cross-sectional view of CC in the middle; Figure 11 The following are provided for the embodiments of this application: Figure 2 Cross-sectional view of DD.

[0041] Among them, 1. Anti-collision beam; 1a. First anti-collision beam; 1b. Second anti-collision beam; 11. Connecting end; 111. Recessed part; 112. First protruding part; 113. Second protruding part; 114. Third protruding part; 115. First straight part; 116. Second straight part; 12. Main body section; 121. First irregular section; 1211. Vertical part; 1212. C-shaped part; 122. Second irregular section; 123. Third irregular section; 2. Install the bracket; 3. Inner door panel. Detailed Implementation

[0042] The embodiments of this application will be described below with reference to the accompanying drawings and preferred embodiments. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. This application can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. It should be understood that the preferred embodiments are only for illustrating this application and are not intended to limit the scope of protection of this application.

[0043] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this application. Therefore, the drawings only show the components related to this application and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0044] Please see Figures 1 to 11 This application provides an embodiment of a crash beam 1, which is a variable cross-section beam, such as... Figure 1 As shown, it can be customized according to the complex internal spatial structure of the door assembly; the cross-sectional shape and size of the anti-collision beam 1 can be flexibly changed according to the layout of the door inner panel 3, reinforcing plate, window regulator and other components to adapt to the layout requirements of the door assembly and the whole vehicle.

[0045] In addition, the variable cross-section beam can be designed specifically according to the magnitude and direction of the collision force borne by the anti-collision beam 1 at different locations. In areas where the expected collision force is large, the cross-sectional size and shape of the anti-collision beam 1 can be optimized, for example, by increasing the thickness of the material or using a more reasonable cross-sectional shape (such as polygons, irregular shapes, etc.) to improve the bending and torsional strength of the area, effectively absorb and disperse collision energy, and reduce the injury to the door and occupants. In areas where the expected collision force is small, the cross-sectional size can be appropriately reduced to reduce weight and achieve the best balance between mechanical performance and material usage.

[0046] The variable cross-section beam is a hollow structure, which ensures that all sections of the beam are closed structures, resulting in excellent strength and resistance to bending and torsion, effectively improving side-impact performance. Figures 4 to 11 As shown.

[0047] Meanwhile, by setting a hollow structure, the use of materials in non-critical areas can be reduced, achieving an overall weight reduction for the anti-collision beam 1. Moreover, the hollow cavity inside the variable cross-section beam provides a controllable deformation space for absorbing collision energy. By optimizing the cavity shape (such as polygonal or irregular shapes) and wall thickness, the anti-collision beam 1 can be guided to collapse along a predetermined path during a collision, avoiding fracture caused by local stress concentration.

[0048] The anti-collision beam 1 includes connecting ends 11 at both ends of the variable cross-section beam. The connecting ends 11 are used to connect to the mounting bracket 2, such as... Figures 1 to 3 As shown, this enables the anti-collision beam 1 to be assembled on the door assembly.

[0049] Multiple recessed portions 111 facing inward and multiple protruding portions facing outward are alternately formed on the outer peripheral surface of the connecting end 11, which can make the outer peripheral surface of the connecting end 11 of the anti-collision beam 1 uneven. When the connecting end 11 is embedded or integrally formed with the mounting bracket 2, the contact area between the connecting end 11 and the mounting bracket 2 can be increased, which is beneficial to improving the circumferential firmness and stability of the connection between the end of the anti-collision beam 1 and the mounting bracket 2, thereby improving the durability of the connection structure between the anti-collision beam 1 and the mounting bracket 2.

[0050] It should be noted that when the anti-collision beam 1 is subjected to external forces such as side impacts, the connecting end 11 will bear a large shear force. The alternating recesses 111 and protrusions increase the contact area between the connecting end 11 and the mounting bracket 2, allowing the shear force to be more evenly distributed on the connecting surface. Compared with the traditional smooth connecting surface, this uneven structure can effectively resist shear deformation and prevent relative sliding between the connecting end 11 and the mounting bracket 2, thereby improving the shear resistance of the anti-collision beam 1 during the collision process and ensuring that the anti-collision beam 1 can stably perform its energy absorption and buffering functions.

[0051] When the mounting bracket 2 is integrally formed onto the outer periphery of the connecting end 11 using die casting, the molten metal fills the recessed portion 111 and wraps around the protruding portion during the die casting process, forming a mechanical interlocking structure. This mechanical interlocking structure transforms the connection between the connecting end 11 and the mounting bracket 2 from simple surface adhesion to deep mechanical engagement, directly increasing the coefficient of friction between the connecting end 11 and the mounting bracket 2. During vehicle operation, this prevents vibration and impact forces from causing the connection between the anti-collision beam 1 and the mounting bracket 2 to loosen.

[0052] The adjacent recesses 111 and protrusions are smoothly connected, which makes the stress distribution in the connection area between the recesses 111 and protrusions more uniform and avoids stress concentration in the connection area between the recesses 111 and protrusions.

[0053] It should be noted that during long-term use, the connection structure between the anti-collision beam 1 and the mounting bracket 2 is subjected to cyclic loads. Even at low stress levels, sharp corners are prone to developing microcracks due to fatigue, which can gradually propagate and lead to fracture. This application eliminates sharp corners in the connection area through a smooth transition between the recessed portion 111 and the protruding portion, reducing the possibility of crack initiation, significantly improving the fatigue limit of the connection end 11, and extending the service life of the anti-collision beam 1.

[0054] In some embodiments of this application, please refer to Figures 4 to 8 The multiple protrusions include multiple first protrusions 112 and multiple second protrusions 113. The maximum curvature of the first protrusions 112 is greater than that of the second protrusions 113, allowing multiple protrusions with different curvatures to be formed on the outer circumferential surface of the connecting end 11. The larger curvature of the first protrusions 112 allows for a deeper mechanical interlocking structure between the first protrusions 112 and the mounting bracket 2. When integrally formed with the anti-collision beam 1 using methods such as die casting, the molten metal can better encapsulate the first protrusions 112, forming a robust mechanical interlock. This interlocking structure effectively prevents the connecting end 11 from separating from the mounting bracket 2 when subjected to tensile or shear forces. The smaller curvature of the second protrusions 113 provides a smoother contact surface, acting as a buffer and transition during stress transmission.

[0055] In some embodiments of this application, please refer to Figures 4 to 8 The first protrusion 112 and the second protrusion 113 are connected by the recess 111, and the first protrusion 112 and the recess 111, as well as the recess 111 and the second protrusion 113, are smoothly connected. Different degrees of unevenness can be formed on the circumferential surface of the connecting end 11, increasing the structural complexity of the outer circumferential surface of the connecting end 11, and further improving the connection firmness when the end of the anti-collision beam 1 and the mounting bracket 2 are integrally formed.

[0056] In addition, when the connection end 11 is subjected to external forces (such as the force transmitted by the mounting bracket 2), this complex end structure can disperse the stress along different paths, reducing the risk of structural damage caused by local stress concentration.

[0057] In some embodiments of this application, please refer to Figure 8 The multiple protrusions also include a third protrusion 114, and the maximum curvatures of the first protrusion 112, the second protrusion 113 and the third protrusion 114 are all different, which can further increase the structural complexity of the outer peripheral surface of the connecting end 11 and increase the complexity of the connection surface between the connecting end 11 and the mounting bracket 2, thereby improving the connection firmness when the end of the anti-collision beam 1 and the mounting bracket 2 are integrally formed.

[0058] In some embodiments of this application, please refer to Figure 7 and Figure 8 A straight portion is also formed on the outer peripheral surface of the connecting end 11, which smoothly transitions between two adjacent protrusions; or, the straight portion smoothly transitions between two adjacent recesses 111. When the straight portion smoothly transitions between adjacent protrusions or adjacent recesses 111, it can change the stress transmission path on the outer peripheral surface of the connecting end 11. When the connecting end 11 is subjected to external force, the stress that might originally be concentrated at the apex of the protrusion or the bottom of the recess 111 will be dispersed to a wider area due to the presence of the straight portion, avoiding structural damage caused by excessive local stress and improving the overall tensile strength of the connecting end 11.

[0059] In addition, the presence of the straight section provides a straight positioning surface for the connection between the end of the anti-collision beam 1 and the mounting bracket 2, so that the connection end 11 and the mounting bracket 2 can be accurately connected and matched, which is beneficial to improving the tightness and stability of the connection.

[0060] In some embodiments of this application, please refer to Figure 7 The connecting end 11 has a first straight portion 115, which smoothly transitions between the two first protrusions 112. This allows for stress transfer between the two first protrusions 112 with large curvatures. When the connecting end 11 is subjected to external force, the stress that was originally concentrated in the first protrusions 112 can be evenly distributed to the area between the two protrusions through the first straight portion 115, making the stress distribution of the entire connecting end 11 more uniform and avoiding structural damage caused by excessive local stress.

[0061] In some embodiments of this application, please refer to Figure 8The connecting end 11 has two straight portions: a first straight portion 115 and a second straight portion 116. The first straight portion 115 is connected between two first protrusions 112, and the second straight portion 116 is connected between two third protrusions 114. The first straight portion 115 and the second straight portion 116 are arranged in parallel. The parallel first straight portion 115 and the second straight portion 116 can work together when subjected to force. When subjected to bending or torsional moment, the two straight portions can jointly resist deformation, thereby enhancing the bending and torsional resistance of the connecting end 11.

[0062] In some embodiments of this application, please refer to Figure 2 as well as Figures 4 to 8 The cross-section of the connecting end 11 is a first closed cross-section, giving it excellent strength and resistance to bending and torsion. This first closed cross-section is symmetrical. When the connecting end 11 is connected to the mounting bracket 2 and subjected to tension or compression, the symmetrical cross-section ensures a relatively uniform stress distribution in the circumferential direction of the connecting end 11, avoiding localized stress concentration. Under bending or torsional moments, the symmetrical cross-section also guarantees a reasonable stress distribution in the connecting end 11.

[0063] It should be noted that, due to the good structural stability of the symmetrical cross-section, it can resist deformation and instability caused by various external forces, avoid the additional bending moment caused by the asymmetry of the cross-section, and reduce the torsional and bending deformation of the end structure of the anti-collision beam 1. When the end of the anti-collision beam 1 is subjected to pressure (such as the pressure of die casting injection or external forces during vehicle operation), it can effectively prevent the connection end 11 from deforming and becoming unstable, which is beneficial to improving the overall stability of the structure.

[0064] In some embodiments of this application, please refer to Figures 4 to 8 The shape of the first closed section is circular, rhomboid, elliptical, triangular or trapezoidal.

[0065] Specifically, when the first closed section is formed by alternating multiple protrusions and multiple recesses 111, as shown in the figure... Figure 4 When the circular cross-section is shown, the degree of unevenness on the outer circumferential surface is small, which can make the strength and stiffness of each area of ​​the connection end 11 in the circumferential direction basically consistent, thereby effectively avoiding fracture or deformation caused by stress concentration, improving the reliability and service life of the connection end 11. The near-circular cross-section is easy to process and manufacture, and can achieve a balance between mechanical properties and good manufacturability.

[0066] When the first closed section is formed by alternating multiple protrusions and multiple recesses 111, as shown in the figure Figure 5When a rhombus cross-section is shown, because it has different mechanical properties in the two diagonal directions (i.e., the X and Y directions), the angles and side lengths of the rhombus can be designed according to the actual stress conditions, giving the rhombus cross-section high strength and stiffness in the main stress directions. In addition, the unique shape of the rhombus cross-section can provide clear positioning features for installation. During installation, the position and orientation of the connection end 11 can be quickly and accurately determined by the sides or corners of the rhombus, improving installation efficiency and accuracy.

[0067] When the first closed section is formed by alternating multiple protrusions and multiple recesses 111, as shown in the figure Figure 6 As shown, the elliptical cross-section combines the characteristics of a circular and a rectangular cross-section, exhibiting different mechanical properties in the two principal axis directions (X and Y). The ratio of the major and minor axes of the ellipse can be adjusted according to the actual stress conditions, ensuring sufficient strength and stiffness in the primary stress directions while meeting certain performance requirements in other directions. By changing the dimensions of the major and minor axes of the elliptical cross-section, the bending stiffness can be flexibly adjusted. Furthermore, when spatial constraints exist in the Y direction (which can be the height or width direction, etc.), a flat connecting end 11 can be formed using the elliptical cross-section to accommodate these constraints.

[0068] When the first closed section is formed by connecting multiple protrusions, multiple recesses 111 and straight sections, it is as follows: Figure 7 The triangular cross-section shown in the diagram exhibits good shape stability under pressure, resulting in high strength and stiffness. Especially in situations requiring high pressure, the triangular cross-section effectively disperses pressure, reduces deformation of the connection end 11, and enhances the connection stability between the connection end 11 and the mounting bracket 2.

[0069] When the first closed section is formed by connecting multiple protrusions, multiple recesses 111 and multiple straight sections, it is as follows: Figure 8 When a trapezoidal cross-section is shown, its shape can be designed according to the actual stress conditions, allowing for a more reasonable distribution of material in the stress direction. This enables the trapezoidal cross-section to better adapt to load changes and improve the load-bearing capacity of the connection end 11. By adjusting the dimensions of the upper base, lower base, and height of the trapezoidal cross-section, the torsional resistance and connection stiffness of the connection end 11 can be maximized, meeting the usage requirements under different working conditions.

[0070] It should be noted that the above cross-sectional shapes are all irregular cross-sections with concave and convex surfaces, and each irregular cross-section is symmetrical about the Y-axis. The concave and convex surfaces of the irregular cross-sections can form a mechanical interlock with the mounting bracket 2, and the symmetrical irregular cross-sections can optimize the stress distribution of the connection end 11, thereby improving the circumferential firmness of the connection between the connection end 11 of the anti-collision beam 1 and the mounting bracket 2 while ensuring the mechanical performance of the connection end 11.

[0071] In some embodiments of this application, please refer to Figure 1 The variable cross-section beam also has a main body segment 12 located between the two connecting ends 11. The outer periphery of the main body segment 12 includes multiple smoothly transitioning variable curvature surfaces. These surfaces guide the direction of impact force transmission, allowing the impact force to be dispersed and transmitted along a predetermined path. By rationally designing the curvature changes of the surfaces and the smooth transition connections between them, the impact force can be evenly distributed within the main body segment 12, avoiding structural damage to the anti-collision beam 1 caused by local stress concentration.

[0072] Compared with traditional uniform or simple variable cross-section anti-collision beams 1, the main body segment 12 with variable curvature surface design can reduce the use of unnecessary materials by optimizing the surface shape and thickness distribution while ensuring structural strength and rigidity. This reduces the weight of the anti-collision beam 1, which is beneficial to reducing vehicle energy consumption and improving fuel economy or driving range.

[0073] It should be noted that when designing the variable cross-section beam, its cross-sectional shape, size and cavity structure are optimized in a coordinated manner according to the mechanical requirements of different areas and the overall vehicle layout space. Specifically, the variable cross-section beam can be designed, stress analyzed and optimized using tools such as 3D modeling software and finite element analysis software, so that the variable cross-section beam meets the layout requirements and mechanical performance requirements of the anti-collision beam 1.

[0074] In some embodiments of this application, please refer to Figure 2 and Figure 9 The main body section 12 includes a first irregular section 121, which is used to be installed on the upper part of the door. The cross section of the first irregular section 121 is a second closed section, which is a D-shaped section. It can avoid components such as the window lifting mechanism on the upper part of the door and provide the necessary torsional stiffness within the limited arrangement space.

[0075] Specifically, the cross-section of the first irregular segment 121 includes a vertical portion 1211 extending along the Y direction, which can be used to fit with components such as the window lifting mechanism. The cross-section of the first irregular segment 121 also includes a C-shaped portion 1212 protruding away from components such as the window lifting mechanism, which can further enhance the local structural strength of the first irregular segment 121.

[0076] In some embodiments of this application, please refer to Figure 2 and Figure 10 The main body segment 12 includes a second irregularly shaped segment 122, which is positioned in the main collision area in the middle of the door. The cross-section of the second irregularly shaped segment 122 is a third closed cross-section, which is a flat cross-section (i.e., an optimized flat closed cross-section). The shape of the flat cross-section allows it to form a large supporting plane in the middle of the door, providing stable rigid support for the inner door panel and related connecting components. When subjected to external loads, this cross-section, through its unique geometry, can effectively disperse stress distribution, significantly improving the deformation resistance of the local structure, providing reinforced support for the middle area of ​​the door, ensuring efficient transmission of the overall load, and enhancing the structural stability and overall rigidity of the door assembly.

[0077] In some embodiments of this application, please refer to Figure 2 and Figure 11 The main body section 12 includes a third irregular section 123, which is used to be installed at the lower part of the door. The cross section of the third irregular section 123 is a fourth closed section, which is a circular or square section. This maximizes the radial dimension of the circumcircle of the fourth closed section, thereby maximizing the bending strength and crushing energy absorption capacity of the third irregular section 123. It can more effectively resist the lateral bending force that the lower part of the door may suffer, maintain the stability of the structural shape, and provide reliable lateral support and main safety protection functions for the passenger compartment.

[0078] It should be noted that the second, third, and fourth closed sections do not have sharp connection points, which avoids stress concentration points in the main body section 12 of the anti-collision beam 1 and improves the overall load-bearing capacity of the anti-collision beam 1. The second, third, and fourth closed sections are irregularly shaped sections designed to match the arrangement space of the anti-collision beam 1. Their cross-sectional shapes can be designed and optimized through simulation verification to achieve a balance between vehicle layout and mechanical performance.

[0079] In the above embodiments, the anti-collision beam 1 can be designed with irregular cross-sections, variable cross-sections, etc., according to the overall vehicle layout, so as to meet the needs of various vehicle models.

[0080] Please see Figures 1 to 11 This application also proposes a door assembly, including the anti-collision beam 1 described in the above embodiments, as well as a mounting bracket 2 and a door inner panel 3. A connecting end 11 is inserted into the mounting bracket 2, and the anti-collision beam 1, mounting bracket 2, and door inner panel 3 are an integral structure. The recessed portion 111 and protruding portion on the outer peripheral surface of the connecting end 11 are alternately arranged, significantly increasing the contact area between the anti-collision beam 1 and the mounting bracket 2. Compared to traditional smooth surface connection methods, this special structure can better disperse stress when subjected to external forces.

[0081] When the door inner panel 3, mounting bracket 2 and anti-collision beam 1 are integrated through die casting, the molten metal used to form the mounting bracket 2 can cover the outer periphery of the connecting end 11, fill the recessed part 111 and wrap the protruding part, so that the connecting end 11 and the solidified mounting bracket 2 form a mechanical interlocking structure. This mechanical interlocking structure changes the connection between the connecting end 11 and the mounting bracket 2 from simple surface adhesion to deep mechanical interlocking, which can effectively prevent the connection between the mounting bracket 2 and the anti-collision beam 1 from breaking or falling off.

[0082] In some embodiments of this application, the inner door panel 3 and the mounting bracket 2 are made of aluminum alloy, which can reduce the overall weight of the door assembly; the inner door panel 3 and the mounting bracket 2 are semi-solid die-cast using a die-casting mold, which can form a tight connection with the anti-collision beam 1 and achieve structural integration.

[0083] In some embodiments of this application, please refer to Figure 2 There are multiple anti-collision beams 1, which are arranged sequentially along the height direction of the inner panel 3 of the door, effectively covering different height areas of the door. In a side collision, regardless of whether the impact point is located at the upper, middle, or lower part of the door, there are corresponding anti-collision beams 1 to absorb and disperse the impact force, avoiding excessive local deformation of the door due to blind spots, and providing more comprehensive protection for the passenger compartment.

[0084] Meanwhile, when the car door is subjected to lateral forces, multiple anti-collision beams 1 can distribute the stress over a larger area. Each anti-collision beam 1 can bear a portion of the stress, avoiding structural damage caused by localized stress concentration.

[0085] The two adjacent anti-collision beams 1 are angled together in the vertical direction. This angled arrangement, together with components such as the inner door panel 3, forms a triangular support structure. Due to the stability of a triangle, this structure significantly enhances the overall rigidity of the door. Under lateral forces, the triangular support structure effectively resists deformation, maintaining the shape and structural integrity of the door, preventing excessive inward or outward bulging, and thus better protecting the passenger compartment space.

[0086] As a specific embodiment of this application, please refer to Figure 2 A first anti-collision beam 1a and a second anti-collision beam 1b are provided in the height direction of the inner panel 3 of the door, and the included angle between the first anti-collision beam 1a and the second anti-collision beam 1b is 10°~30°. This arrangement can optimize the collision force transmission path of the door assembly, enhance the torsional stiffness of the structure, and adapt to the interior space layout, which is conducive to further improving the performance and lightweight effect of the integrated structure.

[0087] This application also proposes a vehicle including the door assembly described in the above embodiments. Because the mass of the door assembly is reduced, the unsprung mass of the vehicle (i.e., the mass not supported by springs in the suspension system) can be reduced. With a reduced unsprung mass, the suspension system can respond more quickly and accurately to changes in road surface, allowing the tires to better contact the ground, reducing wheel bounce, and thus improving the vehicle's handling stability and agility. Furthermore, the reduced mass of the door assembly decreases the overall mass of the vehicle, reducing the power output required by the engine and lowering fuel consumption.

[0088] At the same time, due to the improved side impact protection performance of the door assembly, the optimized door assembly can better absorb and disperse collision energy in the event of a side collision, reducing the impact force transmitted to the passenger compartment and protecting the occupants' survival space.

[0089] This application also proposes a method for manufacturing a vehicle door, used to manufacture the vehicle door assembly described in the above embodiments, comprising the following steps: Step 1: Prepare a closed tube blank using high-strength steel plate; specifically, the high-strength steel plate is a high-strength hot-formed steel plate with a tensile strength of 1500MPa~2000MPa, which is made into a closed tube blank through tube rolling and welding processes, and the wall thickness of the closed tube blank can be designed according to the strength requirements of the door anti-collision beam 1.

[0090] In some preferred embodiments of this application, the thickness of the high-strength steel plate is 1.5mm to 3.0mm. This is because when the thickness of the high-strength steel plate is less than 1.5mm, the closed tube blank is prone to bursting during the subsequent hot gas expansion process due to its small wall thickness, resulting in cracks or openings in the variable cross-section beam. Furthermore, the finished anti-collision beam 1 has insufficient resistance to local buckling, making it difficult to meet the collision performance requirements. When the wall thickness of the high-strength steel plate is greater than 3mm, the excessive heat capacity during the subsequent die-casting process will interfere with the metal fusion in the semi-solid die-casting process, leading to a decrease in the connection strength between the connecting end 11 of the anti-collision beam 1 and the mounting bracket 2. This also increases the weight of the anti-collision beam 1, which does not meet the lightweighting target.

[0091] Step 2: After heating the closed tube blank to the austenitizing temperature (usually 900℃~950℃), place it in a hot gas expansion mold and form the variable cross-section beam of the anti-collision beam 1 through the hot gas expansion molding process.

[0092] Specifically, after the closed tube blank heated to the preset temperature is placed in the hot gas expansion mold, the closed tube blank is expanded inside the hot gas expansion mold by high pressure gas (such as nitrogen or air) until the outer surface of the closed tube blank is completely attached to the inner cavity of the hot gas expansion mold, forming a main body segment 12 and a connecting end 11 (i.e., variable cross-section beam) with a precise profile.

[0093] Step 3: The variable cross-section beam is quenched in a hot gas expansion mold to improve the strength of the anti-collision beam 1.

[0094] Specifically, the variable cross-section beam, which is completely fitted with the inner cavity of the hot gas expansion mold, is cooled at a rate higher than the martensitic critical cooling rate of the steel used (typically higher than 27°C / s). This allows the variable cross-section beam to be quenched and shaped inside the hot gas expansion mold, further enhancing the strength of the anti-collision beam 1. The formed variable cross-section beam has closed sections throughout, exhibiting excellent torsional resistance.

[0095] Step 4: Heat the aluminum alloy raw material to a state where solid and liquid coexist, forming a semi-solid slurry, so that the inner door panel 3, mounting bracket 2 and anti-collision beam 1 can be integrally formed by die casting.

[0096] Specifically, selecting suitable aluminum alloy raw materials (usually grades such as A356 and A357 with good fluidity and mechanical properties) is beneficial to improving the fluidity of the molten metal and ensuring the mechanical properties of the mounting bracket 2 and the inner door panel 3 after curing. Pre-treatment of the aluminum alloy raw materials, such as degassing and slag removal, ensures the purity of the semi-cured metal slurry after molten metal. If necessary, grain refiners and modifiers can be added to refine the grain size.

[0097] The aluminum alloy raw material is heated to between the solid and liquid phase lines to form a state where solid and liquid coexist (usually 580℃-620℃). The holding time is determined according to the type of alloy and the preparation method, generally 10-30 minutes, to ensure uniform temperature. When forming the semi-solid slurry, mechanical stirring is used to spheroidize the primary solid particles, making the semi-solid slurry more uniform.

[0098] It should be noted that in traditional casting, dendritic primary phases easily lead to the enrichment (segregation) of solute elements between dendrites, forming loose pores. This application utilizes mechanical stirring to spheroidize the primary solid phase particles. The uniformly distributed spherical grains effectively hinder solute diffusion, resulting in a more homogeneous composition. Mechanical stirring breaks down dendrites through the shear force generated by rotating blades or stirring rods, increasing the number of nucleation points and refining the grain diameter. This is beneficial for forming dense aluminum alloy castings, significantly improving the material strength and toughness of the castings, and meeting vehicle safety and lightweight requirements.

[0099] Step 5: Place the quenched variable cross-section beam into the die-casting mold and then close the mold.

[0100] Specifically, the die-casting mold is preheated first, and then the variable cross-section beam (i.e., anti-collision beam 1) obtained in step three is placed inside the die-casting mold, so that the connecting end 11 of the variable cross-section beam is inserted into the forming cavity of the die-casting mold used to prepare the mounting bracket 2, and the mold is closed after the anti-collision beam 1 is fixed.

[0101] Step 6: Inject the semi-solid slurry into the die-casting mold to form an integrated structure of the inner door panel 3, mounting bracket 2, and anti-collision beam 1.

[0102] Specifically, during the process of injecting the semi-solid slurry into the die-casting mold, the injection pressure of the semi-solid slurry is 80MPa~150MPa, which allows the semi-solid slurry to fill all corners of the die-casting mold under high pressure injection, thereby achieving complete filling of the corresponding molding cavities of the inner door panel 3 and each mounting bracket 2, and ensuring that the aluminum alloy mounting bracket 2 after curing and molding is tightly bonded and rigidly connected to the outer peripheral surface of the end of the anti-collision beam 1, thus forming an integrated molding structure of the inner door panel 3, mounting bracket 2 and anti-collision beam 1.

[0103] Step 7: After the aluminum alloy casting has cooled and solidified, remove it and perform necessary cutting, grinding and surface treatment to obtain an integrated door structure (i.e., the door inner panel 3, mounting bracket 2 and anti-collision beam 1 are integrally formed structure) that meets the requirements of dimensional accuracy and surface quality.

[0104] It should be noted that this application uses a die-casting process to solidify the inner door panel 3 and the mounting bracket 2 inside the die-casting mold, and achieves the wrapping of the end of the anti-collision beam 1 by the mounting bracket 2. This eliminates the need for welding, bolting, or other methods to achieve a rigid connection between the anti-collision beam 1 and the mounting bracket 2, thus improving connection strength while simplifying the assembly process. In the above manufacturing process, the hot air expansion process and the die-casting process can be pre-set simultaneously, which helps to shorten the production cycle and achieve mass production.

[0105] The door assemblies manufactured using the aforementioned methods can be widely used in both new energy vehicles and traditional fuel-powered vehicles, and are particularly suitable for luxury sedans, SUVs, and MPVs that prioritize lightweight design and side-impact performance. Taking a mid-to-large-sized sedan as an example, replacing the original stamping and welding method with a hot-expansion process and semi-solid aluminum alloy unibody molding achieves a 5.4% weight reduction, a 7.1% reduction in intrusion, an 18% improvement in side-impact performance, and a reduction in assembly time of approximately 30%, demonstrating promising prospects for industrial application.

[0106] The above embodiments are merely preferred embodiments provided to fully illustrate this application, and the scope of protection of this application is not limited thereto. Equivalent substitutions or modifications made by those skilled in the art based on this application are all within the scope of protection of this application.

Claims

1. A crash beam (1), characterized in that, The anti-collision beam (1) is a variable cross-section beam, and the variable cross-section beam is a hollow structure, including connecting ends (11) at both ends of the variable cross-section beam, and the connecting ends (11) are used to connect with the mounting bracket (2); The outer peripheral surface of the connecting end (11) is alternately formed with a plurality of recessed portions (111) facing inward and a plurality of protruding portions facing outward, and adjacent recessed portions (111) and protruding portions are smoothly connected.

2. The anti-collision beam (1) according to claim 1, characterized in that, The plurality of protrusions include a plurality of first protrusions (112) and a plurality of second protrusions (113), wherein the maximum curvature of the first protrusions (112) is greater than the maximum curvature of the second protrusions (113).

3. The anti-collision beam (1) according to claim 1, characterized in that, A straight portion is also formed on the outer peripheral surface of the connecting end (11), and the straight portion is smoothly connected between two adjacent protrusions; Alternatively, the straight portion may be smoothly connected between two adjacent recessed portions (111).

4. The anti-collision beam (1) according to any one of claims 1 to 3, characterized in that, The cross section of the connecting end (11) is a first closed cross section, and the first closed cross section is a symmetrical cross section.

5. The anti-collision beam (1) according to claim 4, characterized in that, The shape of the first closed section is circular, rhomboid, elliptical, triangular or trapezoidal.

6. The anti-collision beam (1) according to any one of claims 1 to 3, characterized in that, The variable cross-section beam also has a main body segment (12) located between the two connecting ends (11), and the outer peripheral surface of the main body segment (12) includes multiple smoothly transitioned variable curvature surfaces.

7. The anti-collision beam (1) according to claim 6, characterized in that, The main body segment (12) includes a first irregular segment (121), which is used to be installed on the upper part of the door. The cross section of the first irregular segment (121) is a second closed cross section, which is a D-shaped cross section.

8. The anti-collision beam (1) according to claim 6, characterized in that, The main body segment (12) includes a second irregular segment (122), which is used to be set in the middle of the door. The cross section of the second irregular segment (122) is a third closed cross section, which is a flat cross section.

9. The anti-collision beam (1) according to claim 6, characterized in that, The main body segment (12) includes a third irregular segment (123), which is used to be installed at the lower part of the door. The cross section of the third irregular segment (123) is a fourth closed cross section, which is a circular cross section or a square cross section.

10. A vehicle door assembly, characterized in that, The system includes a crash beam (1) as described in any one of claims 1 to 9, a mounting bracket (2) and a door inner panel (3), wherein the connecting end (11) is inserted into the mounting bracket (2), and the crash beam (1), the mounting bracket (2) and the door inner panel (3) are an integral structure.

11. The door assembly according to claim 10, characterized in that, The number of anti-collision beams (1) is multiple, and the multiple anti-collision beams (1) are arranged sequentially along the height direction of the inner panel (3) of the car door, and the two adjacent anti-collision beams (1) are arranged at an angle.

12. A vehicle, characterized in that, Includes the door assembly as described in claim 10 or 11.

13. A method for manufacturing a car door, characterized in that, The method for manufacturing the door assembly as described in claim 10 or 11 includes the following steps: Closed tube blanks are prepared using high-strength steel plates; After heating the closed tube blank to the austenitizing temperature, it is placed in a hot gas expansion mold and formed by hot gas expansion molding process to form the variable cross-section beam of the anti-collision beam (1), and the variable cross-section beam is quenched in the hot gas expansion mold. The aluminum alloy raw material is heated to a state in which solid and liquid coexist, forming a semi-solid slurry. After the quenched variable cross-section beam is pre-placed in the die-casting mold, the mold is closed. The semi-solid slurry is injected into the die-casting mold to form an integrated structure of the inner door panel (3), mounting bracket (2) and anti-collision beam (1).

14. The method for manufacturing a car door according to claim 13, characterized in that, The high-strength steel plate is a high-strength hot-formed steel plate with a tensile strength of 1500MPa~2000MPa and a thickness of 1.5mm~3.0mm.

15. The method for manufacturing a car door according to claim 13, characterized in that, When forming the semi-solid slurry, the primary solid particles are spheroidized by mechanical stirring.

16. The method for manufacturing a vehicle door according to any one of claims 13 to 15, characterized in that, During the process of injecting the semi-solid slurry into the die-casting mold, the injection pressure of the semi-solid slurry is 80MPa~150MPa.

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