Lower vehicle body manufacturing method, lower vehicle body and vehicle

Abstract

The invention relates to a lower vehicle body manufacturing method, a lower vehicle body and a vehicle. The lower vehicle body manufacturing method comprises the steps that a first protection part and a second protection part are manufactured; a front structure is formed through an integrated casting forming technology, and the front structure and the first protection piece form a first integrated structure in the front structure forming process; a rear structure is formed through the integrated casting forming technology, and the rear structure and the second protection piece form a second integrated structure in the rear structure forming process; and a middle part is formed through an integrated casting forming technology, and the two ends of the middle part are combined with the first protection piece and the second protection piece in the middle part forming process, so that the middle part, the first integrated structure and the second integrated structure form the lower vehicle body of the integrated structure. In the embodiment of the invention, the lower vehicle body manufactured through the manufacturing method is of an integrated structure, and the quality and performance of the lower vehicle body of the integrated structure can be guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicles, and in particular to a method for manufacturing a lower vehicle body, a lower vehicle body and a vehicle. Background Art

[0002] In the related art, one of the methods for manufacturing the lower body is to integrally die-cast the entire lower body. In order to realize this manufacturing method, large-scale die-casting equipment with very high design and manufacturing costs is required.

[0003] However, when the entire lower body is die-casted in one piece, the die-casting process is too long, and the quality and performance of the end area of the lower body of the final one-piece structure will be degraded to a certain extent, thereby affecting the overall performance of the lower body. Summary of the Invention

[0004] One of the purposes of the present invention is to provide a lower body to solve the technical problem that the quality and performance of the end area of the lower body of the one-piece structure manufactured in the prior art will be attenuated to a certain extent, thereby affecting the overall performance of the lower body; the second purpose is to provide a method for manufacturing the lower body; and the third purpose is to provide a vehicle.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0006] A method for manufacturing a lower vehicle body, comprising:

[0007] manufacturing a first protective member and a second protective member;

[0008] The front structure is formed by an integral casting process, and during the forming process of the front structure, the front structure and the first protective member are formed into a first integral structure; wherein the first protective member is located at a rear end of the first integral structure for connecting to the middle member;

[0009] The rear structure is formed by an integral casting process, and during the forming process of the rear structure, the rear structure and the second protective member are formed into a second integral structure; wherein the second protective member is located at a front end of the second integral structure for connecting to the middle member;

[0010] A middle component is formed between the first integral structure and the second integral structure through an integral casting process, so that the middle component, the first integral structure and the second integral structure form an integral lower vehicle body; wherein the melting point of the material of the first protective component and the second protective component is higher than the melting point of the material of the middle component.

[0011] Furthermore, after forming the rear structure by the integral casting process and forming the rear structure and the second protective member into a second integral structure during the rear structure forming process, and before forming the middle component between the first integral structure and the second integral structure by the integral casting process and forming the middle component, the first integral structure, and the second integral structure into a lower vehicle body of an integral structure, the method further includes:

[0012] Manufacturing a center insert, and connecting a first end of the center insert to the front structure of the first integral structure, and connecting a second end of the center insert to the rear structure of the second integral structure;

[0013] Forming a middle component between the first integral structure and the second integral structure by an integral casting process so that the middle component, the first integral structure and the second integral structure form an integral lower vehicle body includes:

[0014] A middle component is formed outside the middle insert through an integral casting process, so that the middle component, the middle insert, the first integral structure and the second integral structure form a lower vehicle body with an integral structure.

[0015] A lower vehicle body, the lower vehicle body being manufactured by the above-mentioned lower vehicle body manufacturing method;

[0016] The lower body includes a front structure, a first protective member, a middle structure, a second protective member, and a rear structure connected in sequence, the middle structure includes a middle member, and the melting point of the material of the first protective member and the second protective member is higher than the melting point of the material of the middle member;

[0017] The front structure and the rear structure are each an integrally cast structure, the front structure and the first protective member form a first integral structure, and the rear structure and the second protective member form a second integral structure;

[0018] The middle component is an integrally cast structure, and two ends of the middle component are respectively combined with the first protective component and the second protective component.

[0019] Furthermore, the middle structure further includes a middle insert, which is connected to the front structure and the rear structure;

[0020] The middle component is formed outside the middle insert, and the middle component covers the middle insert.

[0021] Furthermore, the middle member includes two sill side beams, the two sill side beams are opposite to each other along the width direction of the lower vehicle body and both extend along the length direction of the lower vehicle body;

[0022] The middle insert includes two threshold inserts, the threshold side beams correspond to the threshold inserts, and the threshold inserts are embedded in the corresponding threshold side beams.

[0023] Furthermore, the middle member further comprises at least one cross beam, the at least one cross beam being located between the two door sill side beams, and the at least one cross beam extending along the width direction of the lower vehicle body;

[0024] The center insert further includes at least one beam insert, and the at least one beam insert corresponds to at least one beam, and the beam insert is embedded in the corresponding beam.

[0025] Furthermore, the threshold insert has a first cavity, the first cavity passes through the threshold insert along the extension direction of the threshold insert, and the circumference of the first cavity is closed or unclosed;

[0026] And / or, the crossbeam insert has a second cavity, the second cavity penetrates the crossbeam insert along the extension direction of the crossbeam insert, and the circumference of the second cavity is closed or unclosed.

[0027] Furthermore, the middle insert is connected to a connecting piece, and the connecting piece is divided into a front connecting piece and a rear connecting piece. The middle insert is connected to the front structure through the front connecting piece, and the middle insert is connected to the rear structure through the rear connecting piece.

[0028] The middle member covers at least a portion of the front connecting member and / or at least a portion of the rear connecting member.

[0029] Furthermore, the front connecting member and the rear connecting member each include a first connecting portion and a second connecting portion, and the first connecting portion and the second connecting portion are bent;

[0030] The first connecting portion and the second connecting portion of the front connecting member are both welded or detachably connected to the front structure, and the first connecting portion and the second connecting portion of the rear connecting member are both welded or detachably connected to the rear structure.

[0031] Furthermore, the front connecting member and the rear connecting member each include a frame and a reinforcement member, the frame has an inner cavity, and the reinforcement member is connected to the frame and is located in the inner cavity.

[0032] Furthermore, the middle insert is a single-layer structure;

[0033] Alternatively, the center insert is a multi-layer structure stacked along the height direction of the lower vehicle body.

[0034] Furthermore, the material of the middle insert is steel, and / or the material of the middle component is aluminum alloy, and / or the material of the first protective member and the second protective member are both steel.

[0035] A vehicle comprises the lower vehicle body described above.

[0036] Beneficial effects of the present invention:

[0037] In the embodiment of the present invention, the front structure forms a first integral structure with the first protective part when integrally cast, the rear structure forms a second integral structure with the second protective part when integrally cast, and the middle part forms an integral lower body with the pre-formed first integral structure and second integral structure when integrally cast. This can avoid a certain attenuation of the quality and performance of the end area of the lower body caused by integral die-casting of the entire lower body, and can ensure the quality and performance of the lower body with an integral structure. The design concept of the lower body with an integral structure combines the integrated die-casting technology with the traditional lower body design concept, and can realize the production of the lower body within the current equipment capabilities, and the manufacturing cost of the lower body is low. In addition, by providing the first protective part and the second protective part, on the one hand, it can prevent the high-temperature molten metal from damaging the front structure and the rear structure when the middle part is integrally cast, thereby avoiding affecting the quality and performance of the lower body, and on the other hand, it can improve the rigidity and collision performance of the lower body. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 A flowchart of a method for manufacturing a lower vehicle body according to an embodiment of the present invention;

[0039] Figure 2 A schematic diagram of the overall structure of the lower vehicle body provided by an embodiment of the present invention;

[0040] Figure 3 A schematic structural diagram of the middle component of the lower vehicle body provided by an embodiment of the present invention;

[0041] Figure 4 A schematic diagram of the structure of the lower vehicle body excluding the middle component provided in an embodiment of the present invention;

[0042] Figure 5 for Figure 4 A magnified schematic diagram of point A in the middle;

[0043] Figure 6 This is a structural schematic diagram of the gate distribution during the integrated low-pressure casting of the middle component of the lower vehicle body provided by an embodiment of the present invention.

[0044] Description of reference numerals:

[0045] 10-front structure, 11-right shock tower, 12-right cabin longitudinal beam, 13-cabin cross beam, 14-left shock tower, 15-left cabin longitudinal beam, 16-front wall cross beam;

[0046] 20- middle structure, 21- middle component, 211- door sill side beam, 212- cross beam, 213- longitudinal beam, 214- second connecting beam, 22- middle insert, 221- door sill insert, 222- cross beam insert;

[0047] 30-Rear structure, 31-Left side member, 32-Left wheel hub cover, 33-Left floor longitudinal member, 34-Floor plane, 35-Right floor longitudinal member, 36-Right wheel hub cover, 37-Right side member, 38-Rear seat cross member;

[0048] 40 - second protective member, 50 - connecting member, 51 - front connecting member, 52 - rear connecting member, 53 - first connecting portion, 54 - second connecting portion, 55 - frame, 56 - reinforcement member, 57 - connecting hole, 60 - gate. DETAILED DESCRIPTION

[0049] The following describes the embodiments of the present invention with reference to the accompanying drawings and preferred embodiments. Those skilled in the art will readily appreciate the other advantages and benefits of the present invention from the disclosure herein. The present invention may also be implemented or applied through various other specific embodiments, and the various details in this specification may be modified or altered based on different viewpoints and applications without departing from the spirit of the present invention. It should be understood that the preferred embodiments are intended only to illustrate the present invention and are not intended to limit the scope of protection of the present invention.

[0050] It should be noted that the illustrations provided in the following embodiments are merely schematic illustrations of the basic concept of the present invention. Therefore, the illustrations only show components related to the present invention and are not drawn according to the number, shape, and size of components in actual implementation. In actual implementation, the type, quantity, and proportion of each component may be changed arbitrarily, and the component layout may also be more complex.

[0051] The traditional method for manufacturing a lower body is to assemble multiple parts into a complete body structure through welding. Although this method is mature, it has certain limitations in terms of material utilization, production efficiency, structural strength, and weight control.

[0052] In the related art, one of the manufacturing methods of the lower body is to die-cast the entire lower body in one piece. In order to realize this manufacturing method, large-scale die-casting equipment with very high design and manufacturing costs is required. Due to the limitations of large-scale die-casting equipment, integrated die-casting is currently mainly used for small and medium-sized vehicle body structural parts. If the entire lower body is to be die-cast, the tonnage of existing die-casting equipment is difficult to achieve. Even if the integrated die-casting of the entire lower body can be achieved through large-scale die-casting equipment, however, when the entire lower body is die-cast in one piece, the quality and performance of the end area of the lower body with the integrated structure that is finally formed will be attenuated to a certain extent due to the long die-casting process, thereby affecting the overall performance of the lower body. In order to solve the above problems, the embodiments of the present invention propose a lower body manufacturing method, a lower body and a vehicle. The above-mentioned lower body manufacturing method, lower body and vehicle are described in detail below.

[0053] In a first aspect, an embodiment of the present invention provides a method for manufacturing a lower vehicle body, wherein the method is used to manufacture the lower vehicle body provided in the first aspect, Figure 1 , the lower car body manufacturing method includes:

[0054] S1, manufacturing a first protective member and a second protective member;

[0055] S2, forming the front structure by an integral casting process, and forming the front structure and the first protective member into a first integral structure during the front structure forming process;

[0056] S3, forming the rear structure through an integral casting process, and forming the rear structure and the second protective member into a second integral structure during the rear structure forming process;

[0057] S4, forming a middle component between the first integral structure and the second integral structure through an integral casting process, so that the middle component, the first integral structure and the second integral structure form an integral lower vehicle body.

[0058] The lower vehicle body manufacturing method is used to manufacture Figures 2 to 5The lower vehicle body is shown. The first protective member is located in the first integral structure for connecting to the rear end of the middle component 21, and the second protective member 40 is located in the second integral structure for connecting to the front end of the middle component 21. The first protective member and the second protective member 40 are prefabricated. The front structure 10 is integrally cast using a first casting device. The first protective member is pre-placed in the first casting device. When the front structure 10 is integrally cast, the front structure 10 is used to connect the rear end of the middle component 21 and is combined with the first protective member, so that the front structure 10 and the first protective member form a first integral structure. The rear structure 30 is integrally cast using a second casting device. The second protective member 40 is pre-placed in the second casting device. When the rear structure 30 is integrally cast, the rear structure 30 is used to connect to the front end of the middle component 21 and is combined with the second protective member 40, so that the rear structure 30 and the second protective member 40 form a second integral structure. The middle component 21 is integrally cast by a third casting device. The first integral structure integrating the first protective member and the front structure 10 and the second integral structure integrating the second protective member 40 and the rear structure 30 are pre-placed into the third casting device. When the middle component 21 is integrally cast, the first protective member and the second protective member 40 are respectively combined at both ends of the middle component 21, so that the middle component 21 and the first integral structure and the second integral structure form an integral lower body.

[0059] The front structure 10 may include a right shock tower 11, a right cabin stringer 12, a cabin cross member 13, a left shock tower 14, a left cabin stringer 15, and a dash cross member 16. The center member 21 may be a frame structure. The rear structure 30 may include a left side member 31, a left wheel hub assembly 32, a left floor stringer 33, a floor plane 34, a right floor stringer 35, a right wheel hub assembly 36, a right side member 37, and a rear seat cross member 38.

[0060] The first and second protective members 40 can be elongated sheets, each extending along the width of the lower vehicle body. When the front structure 10 is integrally cast, the dash cross member 16 and the first protective member form an integral structure. When the rear structure 30 is integrally cast, the front end of the floor plane 34 and the second protective member 40 form an integral structure. The dash cross member 16 has a first side facing the rear structure 30, and the first protective member can cover this first side. The front end of the floor plane 34 has a second side facing the front structure 10, and the second protective member 40 can cover this second side.

[0061] The melting point of the material of the first and second protective members 40 is higher than that of the material of the front structure 10 and higher than that of the material of the rear structure 30. The first and second protective members 40 can both be made of steel. The material of the front structure 10 and the rear structure 30 can be the same as that of the middle member 21. The material of the front structure 10, the middle member 21, and the rear structure 30 can be aluminum alloy.

[0062] The front and rear ends of the center member 21 are provided with a first connecting beam and a second connecting beam 214, respectively. Both the first connecting beam and the second connecting beam 214 extend along the width of the lower body. During the integral casting of the center member 21, the first connecting beam is combined with the first protective member, and the second connecting beam 214 is combined with the second protective member 40. This allows the first connecting beam to be integrally connected to the front structure 10 via the first protective member, while the second connecting beam 214 to be integrally connected to the rear structure 30 via the second protective member 40. As a result, the center member 21, the first integral structure, and the second integral structure form a one-piece lower body.

[0063] Types of one-piece casting include one-piece die-casting and one-piece low-pressure casting. The center section 21 is specifically formed using one-piece low-pressure casting equipment. Currently, one-piece die-casting technology below 10,000 tons is already in mass production. The front structure 10 is specifically formed using one-piece die-casting equipment in the 1,000-ton range, significantly reducing the difficulty and cost of die-casting. The rear structure 30 is specifically formed using one-piece die-casting equipment in the 1,000-ton range, significantly reducing the difficulty and cost of die-casting.

[0064] In this embodiment of the present invention, the front structure 10 is integrally cast with the first protective member to form a first integral structure. The rear structure 30 is integrally cast with the second protective member 40 to form a second integral structure. The middle section 21 is integrally cast with the preformed first and second integral structures to form a one-piece lower body. This avoids the degradation of the quality and performance of the lower body's end regions caused by integral die-casting of the entire lower body, thereby ensuring the quality and performance of the one-piece lower body. Furthermore, the provision of the first and second protective members 40 prevents damage to the front and rear structures 10 and 30 from high-temperature molten metal during the integral casting of the middle section 21, thereby preventing any degradation of the lower body's quality and performance. Furthermore, the rigidity and collision resistance of the lower body are improved.

[0065] In some embodiments, S3, after forming the rear structure through an integrated casting process, and forming the rear structure and the second protective component into a second integrated structure during the rear structure forming process, S4, before forming the middle component between the first integrated structure and the second integrated structure through an integrated casting process, so that the middle component, the first integrated structure and the second integrated structure form an integrated lower body, also includes: manufacturing a middle insert, and connecting the first end of the middle insert to the front structure in the first integrated structure, and connecting the second end of the middle insert to the rear structure in the second integrated structure; forming the middle component between the first integrated structure and the second integrated structure through an integrated casting process, so that the middle component, the first integrated structure and the second integrated structure form an integrated lower body, including: forming the middle component outside the middle insert through an integrated casting process, so that the middle component, the middle insert, the first integrated structure and the second integrated structure form an integrated lower body.

[0066] Among them, the middle part 21 and the middle insert 22 form the middle structure 20, and the middle structure 20 is used to connect the battery pack. The first end of the middle insert 22 is also the end of the middle insert 22 used to connect to the front structure 10, and the second end of the middle insert 22 is also the end of the middle insert 22 used to connect to the rear structure 30. The middle insert 22 can be a frame structure. The material of the middle insert 22 is metal, and the melting point of the material of the middle insert 22 is higher than the melting point of the material of the middle part 21. The material of the middle insert 22 can be steel, for example, high-strength steel. The middle insert 22 can be directly connected to the front structure 10 and the rear structure 30, or it can be connected to the front structure 10 and the rear structure 30 through the connector 50. The middle insert 22 can include a door sill insert 221 and a crossbeam insert 222.

[0067] The front structure 10 is integrally die-cast and formed with the first protective member to form a first integral structure. Assembly holes and surfaces are then machined, and standard components are installed. After testing, the front structure 10 is connected to the center insert 22. The rear structure 30 is integrally die-cast and formed with the second protective member 40 to form a second integral structure. Assembly holes and surfaces are then machined, and standard components are installed. After testing, the rear structure 30 is connected to the center insert 22 after passing the testing.

[0068] The method of forming the middle component 21 outside the middle insert 22 by the one-piece casting process specifically includes: forming the middle component 21 outside the middle insert 22 by the one-piece low-pressure casting process. In the process of forming the middle component 21 outside the middle insert 22 by the one-piece low-pressure casting process, a multi-point pouring method can be used. The distribution of the gate 60 during the one-piece low-pressure casting of the middle component 21 can be referred to. Figure 6 The number of gates 60 can be adjusted according to the number and size of the beam inserts 222 .

[0069] In this embodiment, the provision of the center insert 22 can, on the one hand, improve the rigidity and collision performance of the lower body; on the other hand, by pre-connecting the front structure 10 and the rear structure 30 through the center insert 22, the relative position between the front structure 10 and the rear structure 30 can be ensured to be accurate and stable during the integral casting process of the center component 21.

[0070] Secondly, refer to Figures 2 to 4 The lower body provided by the embodiment of the present invention is manufactured by the lower body manufacturing method provided by the first aspect, and the lower body includes a front structure 10, a first protective member, a middle structure 20, a second protective member 40 and a rear structure 30 connected in sequence, the middle structure 20 includes a middle component 21, and the melting points of the materials of the first protective member and the second protective member 40 are both higher than the melting point of the material of the middle component 21; the front structure 10 and the rear structure 30 are each an integral casting structure, the front structure 10 and the first protective member form a first integral structure, and the rear structure 30 and the second protective member 40 form a second integral structure; the middle component 21 is an integral casting structure, and the two ends of the middle component 21 are respectively combined with the first protective member and the second protective member 40.

[0071] Among them, the lower body is applied to the vehicle. In the description of this embodiment, the front and rear directions are consistent with the front and rear directions of the vehicle, and the left and right directions are consistent with the left and right directions of the vehicle. The middle structure 20 is used to connect the battery pack. The middle structure 20 can be composed of only the middle component 21, or it can be composed of the middle component 21 and other components located between the front structure 10 and the rear structure 30. Along the length direction of the lower body, the front structure 10, the first protective member, the middle structure 20, the second protective member 40 and the rear structure 30 are connected in sequence. The length direction of the lower body is consistent with the length direction of the entire vehicle, and the length direction of the lower body can be referred to. Figure 2 The arrow in B shows the direction.

[0072] The front structure 10 may include a right shock tower 11, a right cabin longitudinal beam 12, a cabin cross beam 13, a left shock tower 14, a left cabin longitudinal beam 15 and a front wall cross beam 16. The cabin cross beam 13 and the front wall cross beam 16 are located at the front and rear ends of the front structure 10 respectively. The cabin cross beam 13 and the front wall cross beam 16 both extend along the width direction of the lower body. The width direction of the lower body is consistent with the width direction of the entire vehicle. The width direction of the lower body can be referred to Figure 2 The right cabin longitudinal beam 12 and the left cabin longitudinal beam 15 are connected to the front collision beam. The size of the front collision beam can be adjusted according to the size of the vehicle model to achieve the platform expansion of the lower body.

[0073] The center member 21 can be a frame structure. The rear structure 30 can include a left side member 31, a left wheel hub cover 32, a left floor rail 33, a floor plane 34, a right floor rail 35, a right wheel hub cover 36, a right side member 37, and a rear seat cross member 38. The left and right floor rails 33 and 35 connect to the rear impact beam, the size of which can be adjusted according to the vehicle model to achieve a platform-like expansion of the lower body.

[0074] The first protective member is located at the rear end of the front structure 10 near the center section 21, and the second protective member 40 is located at the front end of the rear structure 30 near the center section 21. During molding, the front structure 10 and the first protective member form a first integral structure, while during molding, the rear structure 30 and the second protective member 40 form a second integral structure. The first and second protective members 40 can be elongated, sheet-like structures, each extending along the width of the lower vehicle body. When the front structure 10 is integrally cast, the dash cross member 16 and the first protective member form an integral structure. When the rear structure 30 is integrally cast, the front end of the floor plane 34 and the second protective member 40 form an integral structure. The dash cross member 16 has a first side facing the rear structure 30, and the first protective member can cover this first side. The front end of the floor plane 34 has a second side facing the front structure 10, and the second protective member 40 can cover this second side.

[0075] The melting point of the material of the first and second protective members 40 is higher than that of the material of the front structure 10 and higher than that of the material of the rear structure 30. The first and second protective members 40 can both be made of steel. The material of the front structure 10 and the rear structure 30 can be the same as that of the middle member 21. The material of the front structure 10, the middle member 21, and the rear structure 30 can be aluminum alloy.

[0076] The front and rear ends of the center member 21 are provided with a first connecting beam and a second connecting beam 214, respectively. Both the first connecting beam and the second connecting beam 214 extend along the width of the lower body. During the integral casting of the center member 21, the first connecting beam is combined with the first protective member, and the second connecting beam 214 is combined with the second protective member 40. As a result, the first connecting beam is integrally connected to the front structure 10 via the first protective member, and the second connecting beam 214 is integrally connected to the rear structure 30 via the second protective member 40. As a result, the center member 21, the first integral structure, and the second integral structure form the lower body.

[0077] In the embodiment of the present invention, the front structure 10 is integrally cast with the first protective member to form a first integral structure, the rear structure 30 is integrally cast with the second protective member 40 to form a second integral structure, and the middle component 21 is integrally cast with the pre-formed first and second integral structures to form the lower body. This avoids the degradation of the quality and performance of the end region of the lower body caused by integral die-casting of the entire lower body, thereby ensuring the quality and performance of the lower body as a one-piece structure. The design concept of the lower body with this one-piece structure combines integrated die-casting technology with traditional lower body design concepts, enabling the production of the lower body within the capabilities of current equipment and at a low manufacturing cost. In addition, the provision of the first and second protective members 40 prevents, on the one hand, the high-temperature molten metal from damaging the front structure 10 and rear structure 30 during the integral casting of the middle component 21, thereby preventing the quality and performance of the lower body from being affected. On the other hand, it improves the rigidity and collision resistance of the lower body.

[0078] In some embodiments, reference Figure 4 The middle structure 20 also includes a middle insert 22, which is connected to the front structure 10 and the rear structure 30; when the middle component 21 is formed, the middle component 21 is formed outside the middle insert 22, and the middle component 21 covers the middle insert 22.

[0079] The lower body is formed by the middle component 21, the middle insert 22, the first integral structure, and the second integral structure. The middle insert 22 may be a frame structure. The material of the middle insert 22 is metal, and the melting point of the material of the middle insert 22 is higher than the melting point of the material of the middle component 21. The material of the middle insert 22 may be steel, for example, high-strength steel. The middle insert 22 may be directly connected to the front structure 10 and the rear structure 30, or it may be connected to the front structure 10 and the rear structure 30 via a connector 50. The front end of the middle insert 22 is connected to both ends of the front cross member 16, and the rear end of the middle insert 22 is specifically connected to the left beam 31 and the right beam 37 of the rear structure 30.

[0080] The front structure 10 is integrally die-cast and formed with the first protective member to form a first integral structure. Assembly holes and surfaces are then machined, and standard components are installed. After testing, the front structure 10 is connected to the center insert 22. The rear structure 30 is integrally die-cast and formed with the second protective member 40 to form a second integral structure. Assembly holes and surfaces are then machined, and standard components are installed. After testing, the rear structure 30 is connected to the center insert 22 after passing the testing.

[0081] In this embodiment, the provision of the center insert 22 can, on the one hand, improve the rigidity and collision performance of the lower body; on the other hand, by pre-connecting the front structure 10 and the rear structure 30 through the center insert 22, the relative position between the front structure 10 and the rear structure 30 can be ensured to be accurate and stable during the integral casting process of the center component 21.

[0082] In some embodiments, reference Figure 3 and Figure 4 The middle component 21 includes two sill side beams 211, which are opposite to each other along the width direction of the lower vehicle body and extend along the length direction of the lower vehicle body; the middle insert 22 includes two sill inserts 221, the sill side beams 211 correspond to the sill inserts 221, and the sill inserts 221 are embedded in the corresponding sill side beams 211.

[0083] The two sill side beams 211 are located one on the left and one on the right, and the two sill inserts 221 are located one on the left and one on the right. The sill side beams 211 are hollow, and the sill inserts 221 are located within the sill side beams 211. In this embodiment, the sill inserts 221 are embedded in both sill side beams 211, thereby improving the rigidity and collision resistance of the lower vehicle body.

[0084] In some embodiments, reference Figure 3 and Figure 4 The middle component 21 also includes at least one cross beam 212, at least one cross beam 212 is located between the two door sill side beams 211, and at least one cross beam 212 extends along the width direction of the lower vehicle body; the middle insert 22 also includes at least one cross beam insert 222, at least one cross beam insert 222 corresponds to at least one cross beam 212, and the cross beam insert 222 is embedded in the corresponding cross beam 212.

[0085] The number of crossbeams 212 can be two, three, four, five, or other. Along the length of the lower body, at least one crossbeam 212 is located between the first connecting beam and the second connecting beam 214. The number of crossbeam inserts 222 is equal to the number of crossbeams 212, and they correspond one to one. The ends of the crossbeam inserts 222 are respectively connected to the two door sill inserts 221, which can be connected by welding. In this embodiment, in addition to the door sill inserts 221, a corresponding crossbeam insert 222 is embedded in each crossbeam 212, further improving the rigidity and crash resistance of the lower body.

[0086] In some embodiments, reference Figure 3 The middle member 21 further includes a longitudinal beam 213 , which is located between the two sill side beams 211 . The longitudinal beam 213 extends along the length direction of the lower vehicle body and is connected to each cross beam 212 .

[0087] In some embodiments, the sill insert 221 has a first cavity, which penetrates the sill insert 221 along the extension direction of the sill insert 221, and the first cavity is circumferentially closed or unclosed; and / or, the beam insert 222 has a second cavity, which penetrates the beam insert 222 along the extension direction of the beam insert 222, and the second cavity is circumferentially closed or unclosed.

[0088] The circumference of the first cavity refers to the direction of a circle around the boundary of the sill insert 221 within a cross section perpendicular to the extension direction of the sill insert 221, and the circumference of the second cavity refers to the direction of a circle around the boundary of the sill insert 222 within a cross section perpendicular to the extension direction of the crossbar insert 222. When the first cavity is circumferentially closed, the sill insert 221 may have a square cross-sectional shape and may include an upper plate portion, a lower plate portion, a left side plate portion, and a right side plate portion. The upper plate portion and the lower plate portion are opposite each other, and the left side plate portion and the right side plate portion are opposite each other. The upper, lower, left, and right side plates form the first cavity. When the first cavity is not circumferentially closed, the sill insert 221 may have a C-shaped cross-sectional shape and may include an upper plate portion, a lower plate portion, a right side plate portion, a left upper section, and a left lower section. The upper, lower, right side plate portion, left upper section, and left lower section form the first cavity. The left upper section and the left lower section are spaced apart, and the spaced apart portion forms a side opening of the first cavity.

[0089] When the second cavity is circumferentially closed, the cross-section of the cross-beam insert 222 can be square. The cross-beam insert 222 can include an upper plate, a lower plate, a front side plate, and a rear side plate, with the front side plate opposing the rear side plate, and the upper, lower, front side plate, and rear side plate forming the second cavity. When the second cavity is not circumferentially closed, the cross-section of the cross-beam insert 222 can be C-shaped. The cross-beam insert 222 can include an upper plate, a lower plate, a rear side plate, a front upper section, and a front lower section, and the upper, lower plate, rear side plate, front upper section, and front lower section forming the second cavity. The front upper section and the front lower section are spaced apart, and the spaced apart portion forms a side opening of the second cavity.

[0090] The rocker insert 221 and crossbeam insert 222 can be stamped, specifically from high-strength steel. The thickness and width of the rocker insert 221 and crossbeam insert 222 can be adjusted based on the lower body rigidity and crash performance requirements, and their length can be adjusted based on the size of the battery pack to achieve platform-based design. In this embodiment, the rocker insert 221 has a first cavity, and the crossbeam insert 222 has a second cavity, achieving lightweight design while still meeting performance requirements.

[0091] In some embodiments, reference Figure 2 and Figure 4 The middle insert 22 is connected to a connecting member 50, and the connecting member 50 is divided into a front connecting member 51 and a rear connecting member 52. The middle insert 22 is connected to the front structure 10 through the front connecting member 51, and the middle insert 22 is connected to the rear structure 30 through the rear connecting member 52; the middle part 21 covers at least part of the front connecting member 51 and / or at least part of the rear connecting member 52.

[0092] During molding, the center member 21, the center insert 22, the connector 50, the first integral structure, and the second integral structure form a monolithic lower body. The connector 50 connected to the front end of the center insert 22 is the front connector 51, and the connector 50 connected to the rear end of the center insert 22 is the rear connector 52. The center insert 22 and the connector 50 can be connected by welding, specifically by welding the rocker insert 221 in the center insert 22 to the connector 50. The connector 50 can be made of steel, such as high-strength steel. The structure of the rear connector 52 is identical to that of the front connector 51, differing only in location and connected components.

[0093] The number of front connecting parts 51 can be two, and the two front connecting parts 51 are respectively located on the left and right sides of the center insert 22. The front connecting part 51 on the left and the front connecting part 51 on the right are symmetrically arranged. The center insert 22 is connected to the left end of the front panel cross beam 16 through the front connecting part 51 on the left, and is connected to the right end of the front panel cross beam 16 through the front connecting part 51 on the right.

[0094] There can be two rear connectors 52, one located on the left and one on the right side of the center insert 22. The left rear connector 52 is symmetrically arranged with the right rear connector 52. The center insert 22 is connected to the left side beam 31 via the left rear connector 52, and to the right side beam 37 via the right rear connector 52. In this embodiment, in addition to the connection between the center insert 22 and the connector 50, the center member 21 covers at least a portion of the front connector 51 and / or at least a portion of the rear connector 52, thereby improving the connection reliability between the center structure 20 and the connector 50.

[0095] Before the rocker insert 221 and the crossbeam insert 222 are welded to form the center insert 22 and the center insert 22 is connected to the front structure 10 and the rear structure 30 via the connector 50, the first integral structure integrating the first protective member and the front structure 10 and the second integral structure integrating the second protective member 40 and the rear structure 30 can be placed on the positioning fixture. The positioning structure on the positioning fixture for positioning the front structure 10 and the rear structure 30 is consistent with the corresponding positioning structure in the body-in-white positioning fixture. Place the door sill insert 221, the crossbeam insert 222 and the connecting piece 50 on the positioning tool, then weld the door sill insert 221 to the crossbeam insert 222, weld the door sill insert 221 to the connecting piece 50, and connect the connecting piece 50 to the front structure 10 and the rear structure 30 to ensure the accuracy and consistency of the positions of the first integral structure integrating the first protective part and the front structure 10, the middle insert 22, the connecting piece 50, and the second integral structure integrating the second protective part 40 and the rear structure 30 after connection.

[0096] In some embodiments, reference Figure 5The front connecting member 51 and the rear connecting member 52 both include a first connecting portion 53 and a second connecting portion 54, and the first connecting portion 53 and the second connecting portion 54 are bent; the first connecting portion 53 and the second connecting portion 54 in the front connecting member 51 are both welded or detachably connected to the front structure 10, and the first connecting portion 53 and the second connecting portion 54 in the rear connecting member 52 are both welded or detachably connected to the rear structure 30.

[0097] The first connecting portion 53 is preferably perpendicular to the second connecting portion 54. Both the front connecting member 51 and the rear connecting member 52 include a frame 55 having an inner cavity with an outer opening. The second connecting portion 54 is opposite to the outer opening of the inner cavity. The first connecting portion 53 is specifically the top plate of the frame 55.

[0098] The first connecting portion 53 and the second connecting portion 54 of the front connecting member 51 are preferably detachably connected to the front structure 10, preferably by bolting. The first connecting portion 53 and the second connecting portion 54 of the rear connecting member 52 are preferably detachably connected to the rear structure 30, preferably by bolting. The first connecting portion 53 and the second connecting portion 54 are each provided with a connecting hole 57 for passing a bolt. In this embodiment, the front connecting member 51 forms a double-sided connection with the front structure 10, providing high connection reliability. The rear connecting member 52 forms a double-sided connection with the rear structure 30, providing high connection reliability.

[0099] In some embodiments, reference Figure 5 The front connecting member 51 and the rear connecting member 52 both include a frame 55 and a reinforcement member 56 . The frame 55 has an inner cavity. The reinforcement member 56 is connected to the frame 55 and is located in the inner cavity.

[0100] The frame 55 is specifically a square frame, and the inner cavity of the frame 55 is square. The frame 55 can be manufactured from high-strength steel plates through a stamping and welding process. The reinforcement 56 is rib-shaped. There are multiple reinforcements 56, at least some of which extend along the height direction of the lower body, and at least some of which extend along the length direction of the lower body. The multiple reinforcements 56 form a grid structure. In this embodiment, the provision of the reinforcements 56 can enhance the strength and rigidity of the front connector 51 and the rear connector 52.

[0101] In some embodiments, the center insert 22 has a single-layer structure; alternatively, the center insert 22 has a multi-layer structure stacked along the height of the lower vehicle body. In the case of a multi-layer structure, each layer of the center insert 22 has an identical structure. The multi-layer structure can be a double-layer structure, a triple-layer structure, or other structures. The multi-layer structure can improve the rigidity and crash performance of the center insert 22.

[0102] In some embodiments, the middle component 21 is an integral low-pressure casting structure.

[0103] In the process of forming the middle part 21 outside the middle insert 22 by the one-piece low pressure casting process, a multi-point pouring method can be used. The distribution of the gate 60 during the one-piece low pressure casting of the middle part 21 can be referred to Figure 6 The number of gates 60 can be adjusted according to the number and size of the beam inserts 222 .

[0104] The low-pressure casting process has been applied to the production of engine cylinder heads and has been mass-produced. The internal quality of engine cylinder heads produced based on this process is dense and can meet the various operating conditions of the engine. Because the height of the middle component 21 is lower than that of the engine cylinder head, the current low-pressure casting equipment can easily realize the casting and molding of the middle component 21. The low-pressure casting process design uses multi-point pouring, low-speed filling, and high-pressure solidification. In this embodiment, the middle component 21 adopts an integrated low-pressure casting molding method to ensure the filling quality. The multi-point pouring method can ensure uniform filling, thereby ensuring uniform quality of each part of the middle component 21, avoiding the problem of low end quality caused by the die casting process.

[0105] In some embodiments, the center insert 22 is made of steel, and / or the center member 21 is made of aluminum alloy, and / or both the first and second protective members 40 are made of steel. Steel, which is high in strength, improves the rigidity and crash resistance of the lower vehicle body. Aluminum alloy is used for center member 21, achieving lightweight performance while still meeting performance requirements.

[0106] As an example, the manufacturing method of the lower vehicle body may include:

[0107] A first protective member and a second protective member 40 are manufactured; a front structure 10 is formed by an integrated die-casting process, and during the molding process of the front structure 10, the front structure 10 and the first protective member form a first integrated structure; a rear structure 30 is formed by an integrated die-casting process, and during the molding process of the rear structure 30, the rear structure 30 and the second protective member 40 form a second integrated structure; a center insert 22 is manufactured, and the center insert 22 is connected to the front structure 10 and the rear structure 30 by a connector 50; an assembly formed by connecting the center insert 22, the connector 50, the first integrated structure integrating the first protective member and the front structure 10, and the second integrated structure integrating the second protective member 40 and the rear structure 30 is placed on a low-pressure casting device, and the low-pressure casting device is used to mold the center component 21 outside the center insert 22 by an integrated low-pressure casting process, and during the molding process of the center component 21, the center component 21, the center insert 22, the connector 50, the first integrated structure and the second integrated structure form an integrated lower body. The positioning structures on the low-pressure casting equipment for positioning the front structure 10 and the rear structure 30 are consistent with the corresponding positioning structures in the body-in-white positioning tooling.

[0108] In a third aspect, an embodiment of the present invention provides a vehicle comprising the lower vehicle body provided in the second aspect. The vehicle is an electric vehicle including a battery pack, such as a pure electric vehicle, a plug-in hybrid vehicle, or the like.

[0109] Since the vehicle includes the above-mentioned lower body, it also has the beneficial effects of the above-mentioned lower body, which will not be described in detail here.

[0110] The above embodiments are only preferred embodiments for fully illustrating the present invention, and the protection scope of the present invention is not limited thereto. Any equivalent substitution or modification made by those skilled in the art based on the present invention is within the protection scope of the present invention.

Claims

1. A method for manufacturing a lower vehicle body, characterized in that: include: manufacturing a first protective member and a second protective member; The front structure is formed by an integral casting process, and during the forming process of the front structure, the front structure and the first protective member are formed into a first integral structure; wherein the first protective member is located at a rear end of the first integral structure for connecting to the middle member; The rear structure is formed by an integral casting process, and during the forming process of the rear structure, the rear structure and the second protective member are formed into a second integral structure; wherein the second protective member is located at a front end of the second integral structure for connecting to the middle member; A middle component is formed between the first integral structure and the second integral structure through an integral casting process, so that the middle component, the first integral structure and the second integral structure form an integral lower vehicle body; wherein the melting point of the material of the first protective component and the second protective component is higher than the melting point of the material of the middle component.

2. The method for manufacturing a lower vehicle body according to claim 1, wherein: After the rear structure is formed by the integral casting process and the rear structure and the second protective member are formed into a second integral structure during the rear structure forming process, and before the middle component is formed between the first integral structure and the second integral structure by the integral casting process and the middle component, the first integral structure and the second integral structure form a lower vehicle body of an integral structure, the method further includes: Manufacturing a center insert, and connecting a first end of the center insert to the front structure of the first integral structure, and connecting a second end of the center insert to the rear structure of the second integral structure; Forming a middle component between the first integral structure and the second integral structure by an integral casting process so that the middle component, the first integral structure and the second integral structure form an integral lower vehicle body includes: A middle component is formed outside the middle insert through an integral casting process, so that the middle component, the middle insert, the first integral structure and the second integral structure form a lower vehicle body with an integral structure.

3. A lower vehicle body, characterized in that: The lower vehicle body is manufactured by the lower vehicle body manufacturing method according to claim 1 or 2; The lower vehicle body comprises a front structure (10), a first protective member, a middle structure (20), a second protective member (40) and a rear structure (30) connected in sequence, the middle structure (20) comprises a middle member (21), and the melting points of the materials of the first protective member and the second protective member (40) are both higher than the melting point of the material of the middle member (21); The front structure (10) and the rear structure (30) are each an integrally cast structure, the front structure (10) and the first protective member form a first integral structure, and the rear structure (30) and the second protective member (40) form a second integral structure; The middle component (21) is an integrally cast structure, and two ends of the middle component (21) are respectively combined with the first protective component and the second protective component (40).

4. The lower vehicle body according to claim 3, characterized in that: The middle structure (20) further includes a middle insert (22), and the middle insert (22) is connected to the front structure (10) and the rear structure (30); The middle component (21) is formed outside the middle insert (22), and the middle component (21) covers the middle insert (22).

5. The lower vehicle body according to claim 4, characterized in that: The middle component (21) includes two door sill side beams (211), the two door sill side beams (211) are opposite to each other along the width direction of the lower vehicle body, and both extend along the length direction of the lower vehicle body; The middle insert (22) includes two threshold inserts (221), the threshold side beam (211) corresponds to the threshold inserts (221), and the threshold inserts (221) are embedded in the corresponding threshold side beams (211).

6. The lower vehicle body according to claim 5, characterized in that: The middle component (21) further includes at least one crossbeam (212), the at least one crossbeam (212) being located between the two door sill side beams (211), and the at least one crossbeam (212) extending along the width direction of the lower vehicle body; The center insert (22) further includes at least one crossbeam insert (222), wherein at least one crossbeam insert (222) corresponds to at least one crossbeam (212), and the crossbeam insert (222) is embedded in the corresponding crossbeam (212).

7. The lower vehicle body according to claim 6, characterized in that: The threshold insert (221) has a first cavity, the first cavity passes through the threshold insert (221) along the extension direction of the threshold insert (221), and the circumference of the first cavity is closed or unclosed; And / or, the crossbeam insert (222) has a second cavity, the second cavity passes through the crossbeam insert (222) along the extension direction of the crossbeam insert (222), and the second cavity is circumferentially closed or unclosed.

8. The lower vehicle body according to any one of claims 4 to 7, characterized in that: The middle insert (22) is connected to a connecting piece (50), and the connecting piece (50) is divided into a front connecting piece (51) and a rear connecting piece (52). The middle insert (22) is connected to the front structure (10) through the front connecting piece (51), and the middle insert (22) is connected to the rear structure (30) through the rear connecting piece (52). The middle part (21) covers at least a portion of the front connecting part (51) and / or at least a portion of the rear connecting part (52).

9. The lower vehicle body according to claim 8, characterized in that: The front connecting member (51) and the rear connecting member (52) both include a first connecting portion (53) and a second connecting portion (54), and the first connecting portion (53) and the second connecting portion (54) are arranged in a bent manner; The first connecting portion (53) and the second connecting portion (54) in the front connecting member (51) are both welded or detachably connected to the front structure (10), and the first connecting portion (53) and the second connecting portion (54) in the rear connecting member (52) are both welded or detachably connected to the rear structure (30).

10. The lower vehicle body according to claim 8, characterized in that: The front connecting member (51) and the rear connecting member (52) both include a frame (55) and a reinforcement member (56); the frame (55) has an inner cavity; the reinforcement member (56) is connected to the frame (55) and is located in the inner cavity.

11. The lower vehicle body according to any one of claims 4 to 7, characterized in that: The middle insert (22) is a single-layer structure; Alternatively, the center insert (22) is a multi-layer structure stacked along the height direction of the lower vehicle body.

12. The lower vehicle body according to any one of claims 4 to 7, characterized in that: The material of the middle insert (22) is steel, and / or the material of the middle component (21) is aluminum alloy, and / or the material of the first protection component and the second protection component (40) are both steel.

13. A vehicle, characterized in that: Comprising the lower vehicle body according to any one of claims 3 to 12.

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