Torsion box structure and vehicle

Abstract

The invention discloses a torsion box structure and a vehicle, the torsion box structure comprises a doorsill beam, a floor cross beam and a floor longitudinal beam, the end part of the floor cross beam is connected with the doorsill beam, the front end of the floor longitudinal beam extends towards the inner side surface of the doorsill beam and is connected with the doorsill beam, and the doorsill beam is provided with a first inner cavity; a first reinforcing plate extending in the length direction of the vehicle and a second reinforcing plate extending in the width direction of the vehicle are arranged in the first inner cavity. The scheme that the torsion box structure is arranged in the first inner cavity of the doorsill beam is achieved, the advantages of being small in part number and light in weight are achieved, occupation of the space on the inner side of the doorsill beam is reduced, arrangement space is provided for a passenger compartment and other related parts of a vehicle, meanwhile, the structure strength is high, and the service life is long. The transmission of vehicle collision energy is facilitated, the rusting of the torsion box structure caused by silt and other impurities at the wheels can be greatly avoided, and the durability is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of automobile bodies, and in particular to a torsion box structure and a vehicle. Background Art

[0002] The torsion box structure usually refers to the part where the floor crossbeam, floor longitudinal beam and door sill beam are connected to each other. It has an important influence on the force transmission channel and can effectively transfer energy to the corresponding transmission path when the vehicle collides. However, the existing torsion box structure is usually placed outside the door sill beam, which has many parts, occupies a large space, and is heavy, and cannot adapt to the rapid development of the current automobile market. Summary of the invention

[0003] In view of this, the present invention aims to provide a torsion box structure and a vehicle to solve at least one of the technical problems in the prior art that the torsion box structure has many parts, occupies a large space, and is heavy.

[0004] The present invention provides a torsion box structure, comprising a threshold beam, a floor cross beam and a floor longitudinal beam, wherein the end of the floor cross beam is connected to the threshold beam, the front end of the floor longitudinal beam extends toward the inner surface of the threshold beam and is connected to the threshold beam, the threshold beam has a first inner cavity, a first reinforcing plate extending along the length direction of the vehicle and a second reinforcing plate extending along the width direction of the vehicle are arranged in the first inner cavity.

[0005] Furthermore, the threshold beam includes an outer plate and an inner plate, the outer plate and the inner plate are butted together to form the first inner cavity, and an upper connection point and a lower connection point of the outer plate and the inner plate are staggered.

[0006] Furthermore, the first reinforcing plate is attached to the inner plate, and at least one protrusion is provided on the first reinforcing plate at intervals along the length direction of the vehicle.

[0007] Furthermore, one end of the second reinforcing plate is connected to the outer plate, and the other end extends toward the inner plate to form a protruding structure.

[0008] Furthermore, the first reinforcing plate and the second reinforcing plate are cross-arranged, and the first inner cavity is filled with rust-proof material.

[0009] Furthermore, the outer panel has at least one first step structure along the width direction of the vehicle, and a plurality of the first step structures have a smooth transition therebetween; the inner panel has at least one second step structure along the width direction of the vehicle, and a plurality of the second step structures have a smooth transition therebetween.

[0010] Furthermore, the threshold beam also includes a blocking plate, which is arranged at the rear end of the threshold beam and connected to the outer plate and the inner plate to block the cavity opening of the first inner cavity.

[0011] Furthermore, the floor longitudinal beam at least includes a front beam section and a rear beam section, the front beam section is connected to the door sill beam and extends obliquely toward the inner side of the vehicle to be connected to the rear beam section.

[0012] Furthermore, the front beam section includes an upper plate and a lower plate which are arranged in close contact with each other, the upper plate extends upward near the threshold beam and is closely connected to the threshold beam, and the lower plate extends downward near the threshold beam and is closely connected to the threshold beam.

[0013] The present invention also provides a vehicle, comprising the above-mentioned torsion box structure.

[0014] The present invention realizes a scheme of embedding the torsion box structure in the first inner cavity of the sill beam by arranging the first reinforcing plate and the second reinforcing plate in the first inner cavity of the sill beam. Compared with the scheme of extending the front end of the floor longitudinal beam toward the front of the vehicle and forming a through beam on the inner side of the sill beam in the conventional technology, the torsion box structure of the present invention has fewer parts and lighter weight. By extending and connecting the front end of the floor longitudinal beam toward the inner surface of the sill beam, the space occupied on the inner side of the sill beam is reduced, providing a larger layout space for the passenger compartment and other vehicle-related parts (such as battery packs). At the same time, the first reinforcing plate and the second reinforcing plate are used to improve the structural strength at the force concentration position, which is beneficial to the transmission of vehicle collision energy and improves the vehicle collision score. In addition, compared with the scheme of externally placing the torsion box structure, the present invention embeds the torsion box structure in the first inner cavity of the sill beam, which can largely avoid the rust of the torsion box structure caused by impurities such as mud and sand at the wheel, thereby improving durability.

[0015] The vehicle of the present invention has all the beneficial effects of the above-mentioned torsion box structure, which will not be described in detail here.

[0016] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In the drawings that are not necessarily drawn to scale, the same reference numerals may describe similar parts in different views. The same reference numerals with letter suffixes or different letter suffixes may represent different instances of similar parts. The drawings generally illustrate various embodiments by way of example and not limitation, and together with the specification and claims, are used to illustrate the disclosed embodiments. When appropriate, the same reference numerals are used throughout the drawings to refer to the same or similar parts. Such embodiments are illustrative and are not intended to be exhaustive or exclusive embodiments of the present apparatus or method. The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The illustrative embodiments of the present invention and their description are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0018] Figure 1 is a three-dimensional schematic diagram of the torsion box structure provided by the present invention (only the torsion box structure on one side of the vehicle is shown);

[0019] Figure 2 is an exploded view of the threshold beam provided by the present invention;

[0020] Figure 3 is a schematic top view of the torsion box structure provided by the present invention (only the torsion box structure on one side of the vehicle is shown);

[0021] Figure 4 yes Figure 3 Schematic diagram of the cross-sectional structure at AA in the middle;

[0022] Figure 5 yes Figure 3 Schematic diagram of the cross-sectional structure at the middle BB.

[0023] The above drawings include the following reference numerals:

[0024] 1. Door sill beam; 10. First inner cavity; 11. First reinforcing plate; 111. Protruding portion; 12. Second reinforcing plate; 121. Protruding structure; 13. Outer plate; 131. First step structure; 14. Inner plate; 141. Second step structure; 15. Blocking plate; 2. Floor cross beam; 3. Floor longitudinal beam; 31. Front beam section; 311. Upper plate; 312. Lower plate; 32. Rear beam section. DETAILED DESCRIPTION

[0025] The specific embodiments of the present invention are described in detail below with reference to the accompanying drawings, but are not intended to limit the present invention.

[0026] It should be understood that various modifications may be made to the embodiments disclosed herein. Therefore, the above description should not be considered as limiting, but only as an example of an embodiment. Other modifications within the scope and spirit of the invention will occur to those skilled in the art.

[0027] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and, together with the general description of the invention given above and the detailed description of the embodiments given below, serve to explain the principles of the invention.

[0028] These and other characteristics of the invention will become apparent from the following description of a preferred form of embodiment given as a non-limiting example, with reference to the accompanying drawings.

[0029] It should also be understood that, although the invention has been described with reference to some specific examples, those skilled in the art will be able to realize many other equivalent forms of the invention that have the characteristics recited in the claims and are therefore within the scope of protection defined thereby.

[0030] The above and other aspects, features and advantages of the present invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.

[0031] Specific embodiments of the present invention are described hereinafter with reference to the accompanying drawings; however, it should be understood that the disclosed embodiments are merely examples of the present invention, which may be implemented in a variety of ways. Well-known and / or repeated functions and structures are not described in detail to avoid unnecessary or redundant details that obscure the present invention. Therefore, the specific structural and functional details disclosed herein are not intended to be limiting, but merely serve as a basis and representative basis for the claims to teach those skilled in the art to use the present invention in a variety of ways with substantially any suitable detailed structure.

[0032] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0033] This specification may use the phrases "in one embodiment," "in another embodiment," "in a further embodiment," or "in other embodiments," which may all refer to one or more of the same or different embodiments according to the present invention.

[0034] An embodiment of the present invention provides a torsion box structure, including a sill beam 1, a floor cross beam 2 and a floor longitudinal beam 3, wherein the end of the floor cross beam 2 is connected to the sill beam 1, the front end of the floor longitudinal beam 3 extends toward the inner surface of the sill beam 1 and is connected to the sill beam 1, and the sill beam 1 has a first inner cavity 10, in which a first reinforcing plate 11 extending along the length direction of the vehicle and a second reinforcing plate 12 extending along the width direction of the vehicle are provided.

[0035] Combination Figure 1 and Figure 2 As shown, the Z axis in the figure represents the height direction of the vehicle, the Y axis in the figure represents the length direction of the vehicle, and the X axis in the figure represents the width direction of the vehicle. For example, the positive direction of the Z axis is the top, the negative direction of the Z axis is the bottom, the positive direction of the Y axis is the front, the negative direction of the Y axis is the rear, the positive direction of the X axis is the left, and the negative direction of the X axis is the right. The floor cross beam 2 extends along the width direction of the vehicle, and its end is connected to the inner surface of the door sill beam 1 (the inner surface and the outer surface of the door sill beam 1 refer to the side surface facing the inside of the vehicle and the side surface facing the outside of the vehicle, respectively). The floor longitudinal beam 3 extends along the length direction of the vehicle as a whole, and its front end extends toward and is connected to the inner surface of the door sill beam 1. The door sill beam 1 extends along the length direction of the vehicle as a whole, and has a first inner cavity 10. A first reinforcing plate 11 and a second reinforcing plate 12 are arranged in the first inner cavity 10, wherein the first reinforcing plate 11 extends along the length direction of the vehicle, and the second reinforcing plate 12 extends along the width direction of the vehicle. The first reinforcing plate 11 and the second reinforcing plate 12 can be arranged crosswise with each other, or have a certain offset distance.

[0036] When a head-on collision occurs (i.e., the collision energy starts to be transmitted along the length direction of the vehicle), the collision energy is transmitted toward the width direction of the vehicle at the second reinforcing plate 12, thereby allowing the floor cross beam 2 to participate in the transmission process, and the collision energy continues to be transmitted along the length direction of the vehicle at the first reinforcing plate 11, and then is transmitted to the overall structure of the floor longitudinal beam 3 through the front end of the floor longitudinal beam 3; when a side collision occurs (i.e., the collision energy starts to be transmitted along the width direction of the vehicle), the collision energy passes through the second reinforcing plate 12 and continues to be transmitted along the width direction of the vehicle, and then is transmitted to the overall structure of the floor cross beam 2, and the collision energy is transmitted toward the length direction of the vehicle at the first reinforcing plate 11, thereby allowing the floor longitudinal beam 3 to participate in the transmission process.

[0037] The present invention realizes a scheme of embedding the torsion box structure in the first inner cavity 10 of the sill beam 1 by arranging the first reinforcing plate 11 and the second reinforcing plate 12 in the first inner cavity 10 of the sill beam 1. Compared with the scheme of extending the front end of the floor longitudinal beam 3 toward the front of the vehicle and forming a through beam on the inner side of the sill beam 1 in the conventional technology, the torsion box structure of the present invention has fewer parts and lighter weight. By extending and connecting the front end of the floor longitudinal beam 3 toward the inner surface of the sill beam 1, the occupation of the inner space of the sill beam 1 is reduced, and a larger layout space is provided for the passenger compartment and other vehicle-related parts (such as a battery pack). At the same time, the first reinforcing plate 11 and the second reinforcing plate 12 are used to improve the structural strength at the force concentration position, which is beneficial to the transmission of the vehicle collision energy and improves the vehicle collision score. In addition, compared with the scheme of externally placing the torsion box structure, the present invention embeds the torsion box structure in the first inner cavity 10 of the sill beam 1, which can largely avoid the rust of the torsion box structure caused by impurities such as mud and sand at the wheel, thereby improving the durability.

[0038] Furthermore, the threshold beam 1 includes an outer plate 13 and an inner plate 14 , the outer plate 13 and the inner plate 14 are butted together to form the first inner cavity 10 , and the upper connection and the lower connection of the outer plate 13 and the inner plate 14 are staggered.

[0039] Combination Figures 2 to 5 As shown, the threshold beam 1 is formed by connecting the outer plate 13 and the inner plate 14 to each other, and forms a first inner cavity 10 that runs through the length direction of the vehicle. Figure 4 It can be seen that the upper connection and the lower connection of the outer panel 13 and the inner panel 14 are staggered with each other, so that the upper connection is close to the inside of the vehicle and the lower connection is close to the outside of the vehicle, so that the cross-section of the door sill beam 1 presents an overall inclined structure, providing more space for other components inside the vehicle (such as battery pack).

[0040] Furthermore, the first reinforcing plate 11 is attached to the inner plate 14 , and at least one protrusion 111 is provided on the first reinforcing plate 11 at intervals along the length direction of the vehicle.

[0041] Combination Figures 2 to 5 As shown, the cross-section of the first reinforcing plate 11 is L-shaped, which is attached to the inner wall of the inner panel 14 and can be fixed to the inner panel 14 by welding or bolts. A plurality of protrusions 111 are provided on the first reinforcing plate 11 at intervals along the length direction of the vehicle, and the protrusions 111 protrude from the inner wall of the inner panel 14 toward the outer panel 13.

[0042] In this way, the strength of the rocker beam 1 is improved by the provision of the first reinforcing plate 11, thereby improving the strength of the torsion box structure. The strength of the torsion box structure can be further improved by the provision of the protrusion 111, which is beneficial for the collision energy to be transmitted through the rocker beam 1 along the length direction of the vehicle.

[0043] Furthermore, one end of the second reinforcing plate 12 is connected to the outer plate 13 , and the other end extends toward the inner plate 14 to form a protruding structure 121 .

[0044] Combination Figures 2 to 5 As shown, the second reinforcing plate 12 is in a U shape along the projection parallel to the XY plane in the figure, the open end of the U shape faces the outer plate 13, and is connected to the outer plate 13 by setting a flange structure, and the closed end of the U-shaped structure extends toward the inner plate 14 (equivalent to extending along the width direction of the vehicle), forming a protruding structure 121, which is conducive to the transmission of collision energy along the width direction of the vehicle. Generally speaking, there is a certain distance between the protruding structure 121 and the inner plate 14. When the vehicle is hit sideways, the sill beam 1 will deform to a certain extent before the protruding structure 121 will contact the inner plate 14 to achieve the transmission of collision energy.

[0045] Furthermore, the first reinforcing plate 11 and the second reinforcing plate 12 are cross-arranged, and the first inner cavity 10 is filled with rust-proof material.

[0046] Combination Figures 2 to 5 As shown, the first reinforcing plate 11 is arranged along the length direction of the vehicle, and the second reinforcing plate 12 is arranged along the width direction of the vehicle, and the two are arranged crosswise with each other. According to the analysis of the transmission path of the collision energy, whether it is a side collision or a head-on collision, the bifurcation point of the transmission path is located at the intersection of the end of the floor cross beam 2 and the front end of the floor longitudinal beam 3. In the embodiment of the present invention, the intersection of the transmission path is located in the first inner cavity 10 of the door sill beam 1. Therefore, the first reinforcing plate 11 and the second reinforcing plate 12 are arranged crosswise, which can greatly improve the strength of the torsion box structure at the intersection, effectively decompose the force along the length direction of the vehicle and the force along the width direction of the vehicle, so as to improve the collision performance of the vehicle; the first inner cavity 10 can be filled with anti-rust material, for example, the wax injection anti-rust process can be used to further protect the first reinforcing plate 11 and the second reinforcing plate 12, and prevent the key parts of the torsion box structure from being rusted.

[0047] Furthermore, the outer panel 13 has at least one first step structure 131 along the width direction of the vehicle, and a plurality of the first step structures 131 have a smooth transition therebetween; the inner panel 14 has at least one second step structure 141 along the width direction of the vehicle, and a plurality of the second step structures 141 have a smooth transition therebetween.

[0048] Combination Figure 5As shown, the outer panel 13 has two first step structures 131 along the width direction of the vehicle, and the first step structures 131 have a smooth transition to form a step extending obliquely to the upper right, and the inner panel 14 has a second step structure 141 along the width direction of the vehicle to form a step extending obliquely to the upper right. It can be understood that the number of the first step structure 131 and the second step structure 141 can be designed according to actual needs, which is only shown as an example here without specific limitation.

[0049] In this way, through the first step structure 131 and the second step structure 141, the collision energy can be smoothly transmitted from the lower threshold beam 1 to the higher floor cross beam 2 and floor longitudinal beam 3, avoiding force transmission faults, increasing the cross-sectional force along the width direction of the vehicle, and improving the torsional stiffness and bending stiffness of the entire vehicle.

[0050] Furthermore, the threshold beam 1 further includes a blocking plate 15 , which is disposed at a rear end of the threshold beam 1 and connected to the outer plate 13 and the inner plate 14 to block the opening of the first inner cavity 10 .

[0051] Combination Figure 2 As shown, the blocking plate 15 is arranged at the rear end of the door sill beam 1 and connected to the outer plate 13 and the inner plate 14, so as to block the opening of the first inner cavity 10, and can provide better protection for the first reinforcing plate 11 and the second reinforcing plate 12 in the first inner cavity 10.

[0052] Furthermore, the floor longitudinal beam 3 at least includes a front beam section 31 and a rear beam section 32 , wherein the front beam section 31 is connected to the door sill beam 1 and extends obliquely toward the inner side of the vehicle to be connected to the rear beam section 32 .

[0053] Combination Figure 3 As shown, the floor longitudinal beam 3 includes a front beam section 31 and a rear beam section 32 connected end to end. The rear beam section 32 is used to connect with other components and has a spacing with the front beam section 31 along the vehicle width direction. The front end of the front beam section 31 (that is, the front end of the floor longitudinal beam 3) is connected to the inner surface of the door sill beam 1, and the rear end of the front beam section 31 extends obliquely toward the inner side of the vehicle to be connected with the rear beam section 32, which is beneficial to transmit force to the rear beam section 32, and the front beam section 31 occupies a small space, and other components (such as a battery pack) can be arranged on the inner side of the vehicle corresponding to the front beam section 31.

[0054] Furthermore, the front beam section 31 includes an upper plate 311 and a lower plate 312 which are arranged in a vertically fitted manner. The upper plate 311 extends upward near the threshold beam 1 and is closely connected to the threshold beam 1 , and the lower plate 312 extends downward near the threshold beam 1 and is closely connected to the threshold beam 1 .

[0055] Combination Figure 5As shown, the front beam section 31 includes an upper plate 311 and a lower plate 312 which are arranged in a close relationship with each other. The upper plate 311 extends upward near the sill beam 1 and is closely connected to the inner plate 14 of the sill beam 1. The lower plate 312 extends downward near the sill beam 1 and is closely connected to the inner plate 14 of the sill beam 1, forming a trumpet-shaped cross section. Such a cross section has high strength, which is conducive to the transmission of force from the sill beam 1 to the front beam section 31 along the width direction of the vehicle body, and can avoid the sill beam 1 from being tilted toward the upper side or the lower side of the floor longitudinal beam 3 as a whole during the force transmission process, thereby facilitating a relatively straight force transmission route for the rear beam section 32.

[0056] The present invention also provides a vehicle, comprising the above-mentioned torsion box structure.

[0057] The vehicle of the present invention realizes a scheme of embedding the torsion box structure in the first inner cavity 10 of the sill beam 1 by arranging the first reinforcing plate 11 and the second reinforcing plate 12 in the first inner cavity 10 of the sill beam 1. Compared with the scheme of extending the front end of the floor longitudinal beam 3 toward the front of the vehicle and forming a through beam on the inner side of the sill beam 1 in the conventional technology, the torsion box structure of the present invention has fewer parts and lighter weight. By extending and connecting the front end of the floor longitudinal beam 3 toward the inner surface of the sill beam 1, the space occupied by the inner side of the sill beam 1 is reduced, and a larger layout space is provided for the passenger compartment and other vehicle-related parts (such as a battery pack). At the same time, the first reinforcing plate 11 and the second reinforcing plate 12 are used to improve the structural strength at the force concentration position, which is beneficial to the transmission of the vehicle collision energy and improves the vehicle collision score. In addition, compared with the scheme of externally placing the torsion box structure, the present invention embeds the torsion box structure in the first inner cavity 10 of the sill beam 1, which can largely avoid the rust of the torsion box structure caused by impurities such as mud and sand at the wheel, thereby improving the durability.

[0058] In the above embodiments of the present invention, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0059] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used herein to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" may include both "above" and "below". The device may also be positioned in other different ways, rotated 90 degrees or in other orientations, and the spatially relative descriptions used herein are interpreted accordingly.

[0060] In addition to the above, it should be noted that "one embodiment", "another embodiment", "embodiment", etc. mentioned in this specification refer to the specific features, structures or characteristics described in conjunction with the embodiment included in at least one embodiment generally described in this application. The same expression appearing in multiple places in the specification does not necessarily refer to the same embodiment. Further, when describing a specific feature, structure or characteristic in conjunction with any embodiment, it is claimed that the realization of such feature, structure or characteristic in conjunction with other embodiments also falls within the scope of the present invention.

[0061] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0062] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A torsion box structure, characterized in that: The invention comprises a threshold beam, a floor cross beam and a floor longitudinal beam, wherein the end of the floor cross beam is connected to the threshold beam, the front end of the floor longitudinal beam extends toward the inner surface of the threshold beam and is connected to the threshold beam, the threshold beam has a first inner cavity, a first reinforcing plate extending in the vehicle length direction and a second reinforcing plate extending in the vehicle width direction are arranged in the first inner cavity.

2. The torsion box structure according to claim 1, characterized in that: The threshold beam comprises an outer plate and an inner plate, the outer plate and the inner plate are butted against each other to form the first inner cavity, and the upper connection point and the lower connection point of the outer plate and the inner plate are staggered.

3. The torsion box structure according to claim 2, characterized in that: The first reinforcing plate is attached to the inner plate, and at least one protrusion is arranged on the first reinforcing plate at intervals along the length direction of the vehicle.

4. The torsion box structure according to claim 2, characterized in that: One end of the second reinforcing plate is connected to the outer plate, and the other end extends toward the inner plate to form a protruding structure.

5. The torsion box structure according to claim 2, characterized in that: The first reinforcing plate and the second reinforcing plate are arranged crosswise, and the first inner cavity is filled with rust-proof material.

6. The torsion box structure according to claim 2, characterized in that: The outer panel has at least one first step structure along the vehicle width direction, and a plurality of the first step structures have a smooth transition therebetween; the inner panel has at least one second step structure along the vehicle width direction, and a plurality of the second step structures have a smooth transition therebetween.

7. The torsion box structure according to claim 2, characterized in that: The threshold beam further includes a blocking plate, which is disposed at the rear end of the threshold beam and connected to the outer plate and the inner plate to block the opening of the first inner cavity.

8. The torsion box structure according to claim 1, characterized in that: The floor longitudinal beam at least comprises a front beam section and a rear beam section, wherein the front beam section is connected to the door sill beam and extends obliquely toward the inner side of the vehicle to be connected to the rear beam section.

9. The torsion box structure according to claim 8, characterized in that: The front beam section includes an upper plate and a lower plate which are arranged in close contact with each other. The upper plate extends upward near the threshold beam and is closely connected to the threshold beam, and the lower plate extends downward near the threshold beam and is closely connected to the threshold beam.

10. A vehicle, characterized in that: Including the torsion box structure described in claim 9.

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