Front floor structure for electric vehicle and dynamic regulation method of force transmission path

Abstract

This invention relates to the field of automotive body structure technology, and more particularly to a front floor structure for electric vehicles and a method for dynamically controlling the force transmission path. The front floor structure includes a floor body, a central channel, a front longitudinal beam, an upper crossbeam, a lower crossbeam, and a sill. The central channel and the front longitudinal beam are longitudinally arranged on the top surface of the floor body, with the central channel located in the middle and the front longitudinal beams located on the left and right sides of the central channel. The upper crossbeam is transversely arranged on the top surface of the floor body and connects to the sills at both ends. The upper crossbeam includes a front crossbeam and a rear crossbeam, with the front crossbeam connecting the rear ends of the central channel and the front longitudinal beam. There are at least three lower crossbeams, with two lower crossbeams located on the bottom sides of the front and rear crossbeams, respectively. The front and rear crossbeams, together with their corresponding lower crossbeams and the floor body, form closed cavity structures. This invention solves the problems of single and discontinuous force transmission paths, increases the moment of inertia of the cross section, and reduces the probability of battery compression.

Description

Technical Field

[0001] This invention relates to the field of automotive body structure technology, and in particular to a front floor structure for electric vehicles and a method for dynamic control of force transmission paths. Background Technology

[0002] The front floor structure is a core component of the vehicle's frame, located at the bottom of the passenger compartment. It connects forward to the engine compartment or front cargo compartment, to the side panels on the left and right, and to the rear floor. Its main functions include supporting occupants and component loads, maintaining body rigidity and modal characteristics, controlling noise and vibration (NVH), absorbing and transferring energy in a collision to protect occupants, and, especially crucially in electric vehicles, protecting the under-mounted battery pack from impact damage.

[0003] Traditional front floor structures typically consist of a floor panel, longitudinal and transverse beams, and sills, and their design directly impacts a vehicle's crash safety and structural performance. The central channel of the longitudinal beams is usually located along the vehicle's longitudinal centerline and protrudes. The upper left / right transverse beams employ a segmented structure. In terms of crash safety, this type of structure relies primarily on predetermined force transmission paths, such as the front longitudinal beams and central channel transferring frontal collision energy rearward to the transverse beam structure. The sill structure is mostly made of steel and has a C-shaped or similar simple cross-section.

[0004] Therefore, the existing front floor structure has the following technical problems:

[0005] First, the single frontal and side force transmission path design is prone to local path overload under collision conditions, leading to fracture or structural instability. It cannot effectively disperse impact energy, resulting in increased deformation of the passenger compartment. At the same time, the discontinuity of the force transmission path and insufficient moment of inertia of the cross section increase the risk of structural bending or fracture during a collision, which may lead to the battery pack being crushed, posing a safety hazard.

[0006] Secondly, the traditional three-dimensional protective framework surrounding the battery area is weak, especially in terms of insufficient side and bottom protection. The sill structure has poor bending resistance, and the crossbeam structure is prone to bending or partial tearing during a collision, making it difficult to effectively resist the threat to the battery pack from impacts from all directions.

[0007] Secondly, the sill structure is relatively heavy, which is detrimental to the lightweight requirements and range improvement of electric vehicles. Furthermore, when traditional structures are made lightweight, it is often difficult to simultaneously guarantee sufficient rigidity, modal characteristics, and collision safety, especially in terms of battery protection.

[0008] Finally, the traditional structure of areas such as seat mounting points is a Z-shaped beam, which is not stiff enough and is prone to large deformation and vibration under dynamic loads, affecting NVH performance and ride comfort. In addition, its connection points are prone to failure due to stress concentration in a collision. Summary of the Invention

[0009] In view of the deficiencies of the existing technology, the purpose of the embodiments of the present invention is to provide a front floor structure for an electric MPV with a multi-path efficient force transmission architecture, a high-rigidity closed cavity cross-section design, a lightweight multi-cavity sill, all-round battery protection, and a compact slide rail assembly, so as to improve the body stiffness, modal, collision safety and lightweight level.

[0010] To achieve the above purpose, the embodiments of the present invention provide the following technical solutions:

[0011] A front floor structure for an electric vehicle, comprising a floor body, a middle channel, front longitudinal beams, upper cross beams, lower cross beams and sills; the middle channel and the front longitudinal beams are longitudinally arranged on the top surface of the floor body, the middle channel is located in the middle, and the front longitudinal beams are located on the left and right sides of the middle channel; the upper cross beams are transversely arranged on the top surface of the floor body and both ends are connected to the sills, the upper cross beams include a front cross beam and a rear cross beam, and the front cross beam is connected to the rear ends of the middle channel and the front longitudinal beams; the lower cross beams are transversely arranged on the bottom surface of the floor body and both ends are connected to the sills, there are at least three lower cross beams, two of the lower cross beams are respectively located on the bottom sides of the front cross beam and the rear cross beam, and the front cross beam, the rear cross beam respectively form a closed cavity structure with the corresponding lower cross beam and the floor body.

[0012] Optionally, the cross-sections of the middle channel and the front longitudinal beams are both M-shaped closed cavity structures, and the middle parts of the top surfaces of the middle channel and the front longitudinal beams are recessed downward.

[0013] Optionally, the front cross beam, the rear cross beam and the corresponding lower cross beam and the floor body form a closed cavity structure in the shape of a Chinese character "ri".

[0014] Optionally, the cross-section of the sill is a multi-cavity structure.

[0015] Optionally, it further includes a slide rail assembly, the slide rail assembly includes an upper cover plate, a mounting plate and a reinforcing plate arranged in sequence from top to bottom, the front part of the reinforcing plate is connected to the front cross beam, the middle part is connected to the rear cross beam, the outer side of the rear part is connected to the sill, and the inner side is connected to the floor body; the mounting plate is located above the reinforcing plate and there is a cavity structure between the two; the upper cover plate is installed on the reinforcing plate and the mounting plate, and forms a flat floor surface with the floor body.

[0016] Optionally, it further includes a seat mounting structure, the seat mounting structure is a box-shaped welded part, is arranged on the floor body or the upper cross beam, and is connected to the lower cross beam or the rear cross beam.

[0017] Optionally, the front longitudinal beams, the middle channel and the front cross beam constitute three forward force transmission paths, and the sills, the upper cross beams and the lower cross beams constitute three lateral force transmission paths, jointly forming a three-dimensional protection framework around the battery pack.

[0018] This invention also provides a method for dynamic control of the force transmission path in the front floor structure of an electric vehicle as described above, comprising:

[0019] Acquire acceleration data and vehicle deflection angle during a vehicle collision;

[0020] The collision resultant force direction angle is calculated based on acceleration components, and the collision type is identified by combining the vehicle body deflection angle.

[0021] Real-time detection of deformation parameters at key points of the three force transmission paths, and calculation of load rate for each path;

[0022] Based on the collision type and path load rate deviation, a current control command is output to the intelligent material actuator at the force transmission path connection point to change the damping characteristics of the connection point.

[0023] Optionally, the collision type identification includes: when both the resultant force direction angle and the vehicle body deflection angle are within the preset standard collision range, it is determined to be a standard frontal collision; when the resultant force direction angle exceeds the standard collision range but is less than the preset threshold, it is determined to be an offset collision; when the vehicle body deflection angle exceeds the preset threshold, it is determined to be an oblique collision.

[0024] Optionally, the output current control command includes: when the load rate of a single path is detected to exceed a set threshold, increasing the current of the actuator corresponding to the low-load path to improve its stiffness.

[0025] One or more technical solutions provided in the embodiments of the present invention have at least the following technical effects or advantages:

[0026] 1. In the front floor structure of this invention, the base plate body serves as the basic load-bearing component, connecting the front and rear structures and the left and right thresholds, providing an installation reference for other components. A central channel is located in the middle, with front longitudinal beams on both sides, both arranged longitudinally. These, along with the transverse upper and lower crossbeams, form a crisscrossing frame structure. The front crossbeam connects the central channel and the rear end of the front longitudinal beam, while two lower crossbeams correspond to the bottom sides of the front and rear crossbeams, respectively, allowing the front and rear crossbeams to form closed cavities with their corresponding lower crossbeams and the floor body. This front floor structure, through the coordinated layout of longitudinal and transverse components, constructs a multi-directional force transmission foundation: the longitudinal central channel and front longitudinal beams connect with the transverse front crossbeams to form a positive force transmission path, while the thresholds connect with the upper and lower crossbeams to form a lateral force transmission path. Compared to traditional open or simple cross-section structures, the closed cavity structure improves the structure's moment of inertia and bending resistance, reducing local deformation during collisions. Meanwhile, the components form a surrounding layout around the battery installation area, providing a structural foundation for battery protection. Compared with the traditional segmented structure, this structure solves the problem of single and discontinuous force transmission paths, improving structural integrity. The enclosed cavity increases the moment of inertia of the cross section, reducing the risk of beam bending. The multi-beam layout constructs a three-dimensional protection zone around the battery pack, reducing the probability of battery compression.

[0027] 2. The threshold has a multi-cavity cross-section, forming multiple independent small chambers inside. These multiple cavities can absorb lateral impact energy through the sequential collapse of each chamber, extending the impact force's duration. Simultaneously, the multi-cavity structure enhances the overall stiffness of the threshold, making it more stable when transmitting lateral forces to the upper and lower crossbeams, preventing force transmission interruption caused by excessive deformation of the threshold itself, and solving the problems of low moment of inertia and poor bending resistance of traditional C-shaped thresholds.

[0028] 3. The seat mounting structure adopts a box-shaped structure, which improves the rigidity of the seat mounting point: the force of the seat is distributed to the lower crossbeam or rear crossbeam through the box, avoiding deformation of the mounting point caused by local stress concentration; the closed structure reduces the transmission of vibration between the seat and the body, reduces the resonance amplitude, and improves NVH performance; the connection with the body frame enhances the overall structural load-bearing capacity, which can reduce the intrusion of the passenger compartment caused by the deformation of the seat mounting structure during a collision, and solves the problem of insufficient rigidity of traditional seat mounting structures.

[0029] 4. The dynamic force transmission path control method provides a basis for load distribution through collision type identification, calculates the load rate to reflect the real-time status of the path, and uses current control commands to adjust the path stiffness as needed. In non-standard collisions, it can avoid load imbalance of fixed paths, improve energy absorption efficiency, and solve the problem of poor adaptability of traditional static paths in complex collisions.

[0030] Advantages of additional aspects of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. In addition, the dimensions or spacing between the components are exaggerated to show the position of each component, and the schematic diagrams are for illustrative purposes only.

[0032] Figure 1 This is a schematic diagram of the front floor structure provided in an embodiment of the present invention;

[0033] Figure 2 This is an exploded view (top surface) of the front floor structure provided in an embodiment of the present invention.

[0034] Figure 3 This is an exploded view (bottom surface) of the front floor structure provided in an embodiment of the present invention.

[0035] Figure 4This is a schematic cross-sectional view of the floor structure at point Y0 provided in an embodiment of the present invention;

[0036] Figure 5 This is a schematic diagram of the X-direction cross-section of the floor structure provided in an embodiment of the present invention;

[0037] Figure 6 This is a schematic diagram of the threshold provided in an embodiment of the present invention;

[0038] Figure 7 This is a schematic diagram of the seat installation structure provided in an embodiment of the present invention;

[0039] Figure 8 This is a schematic diagram of the slide rail assembly provided in an embodiment of the present invention;

[0040] Figure 9 This is a diagram illustrating the installation effect of the front floor structure provided in this embodiment of the invention on a complete vehicle.

[0041] Figure 10 This is a top view of the front floor structure provided in an embodiment of the present invention;

[0042] Figure 11 This is a rendering of the bottom surface of the front floor structure provided in an embodiment of the present invention;

[0043] Figure 12 This is an installation effect diagram of the reinforcing plate provided in an embodiment of the present invention;

[0044] Figure 13 This is an installation effect diagram of the mounting plate provided in an embodiment of the present invention;

[0045] Figure 14 This is an installation effect diagram of the top cover plate provided in an embodiment of the present invention;

[0046] In the diagram: 1. Front longitudinal beam; 2. Central aisle; 3. Front crossbeam; 4. Rear crossbeam; 5. Sill; 6. Lower crossbeam; 7. Seat mounting structure; 8. Floor body; 9. Slide rail assembly; 10. Top cover plate; 11. Reinforcing plate; 12. Mounting plate; Detailed Implementation

[0047] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0048] Example 1

[0049] like Figure 1 , Figure 2 , Figure 3 , Figure 10 , Figure 11 As shown, this embodiment proposes a front floor structure for electric vehicles, including a floor body, a central channel 2, a front longitudinal beam 1, an upper crossbeam, a lower crossbeam 6, and a sill 5. The central channel 2 and the front longitudinal beam 1 are longitudinally arranged on the top surface of the floor body, with the central channel 2 located in the middle and the front longitudinal beam 1 located on the left and right sides of the central channel 2. The upper crossbeam is transversely arranged on the top surface of the floor body and connected to the sill 5 at both ends. The upper crossbeam includes a front crossbeam 3 and a rear crossbeam 4. The front crossbeam 3 connects the rear ends of the central channel 2 and the front longitudinal beam 1. The lower crossbeam 6 is transversely arranged on the bottom surface of the floor body and connected to the sill 5 at both ends. There are at least three lower crossbeams 6, with two lower crossbeams 6 located on the bottom sides of the front crossbeam 3 and the rear crossbeam 4, respectively. The front crossbeam 3 and the rear crossbeam 4 form closed cavity structures with the corresponding lower crossbeams 6 and the floor body 8.

[0050] The floor panel serves as the basic support, upon which a central channel 2 and front longitudinal beams 1 are installed. The central channel 2 is located in the middle, with the front longitudinal beams 1 positioned on either side, forming a stable longitudinal structure. The upper crossbeam, comprising the front crossbeam 3 and the rear crossbeam 4, traverses the top surface of the floor panel and connects to the sill 5, while the lower crossbeam 6 is located on the bottom surface of the floor panel, connecting to the sill 5 and forming a closed cavity with the upper crossbeam and the floor panel 8. This front floor structure allows collision energy to be transmitted along multiple paths, avoiding localized stress concentration and enhancing the overall rigidity and stability of the vehicle body. The various components work together to form a complete force transmission network, effectively dispersing collision energy, reducing the risk of passenger compartment deformation, and protecting the safety of occupants, especially excelling in battery protection.

[0051] like Figure 5 As shown, both the central channel 2 and the front longitudinal beam 1 have M-shaped closed cavity structures in cross-section, with the top surface of both the central channel 2 and the front longitudinal beam 1 recessed downwards. Compared to the traditional C-shaped cross-section, the M-shaped structure increases the moment of inertia by approximately 30%, significantly enhancing bending resistance. Upon impact, it effectively resists bending moments, prevents component deformation, maintains structural integrity, and thus improves the stiffness mode of the vehicle body frame.

[0052] like Figure 4 As shown, the front crossbeam 3, the rear crossbeam 4, the corresponding lower crossbeam 6, and the floor body 8 form a U-shaped closed cavity structure. The U-shaped closed cavity structure is formed by the front crossbeam 3, the rear crossbeam 4, the corresponding lower crossbeam 6, and the floor body 8 respectively enclosing the cavity, forming a cavity with two layers and a middle separation.

[0053] The multi-partition design of the H-shaped cavity allows the force to be dispersed and transmitted through multiple cavity walls when the structure is subjected to lateral forces, reducing stress concentration in one direction. After being connected with the longitudinal components of the M-shaped cross section, the longitudinal and lateral closed cavities support each other to form a three-dimensional rigid frame, which allows the energy of frontal or side collisions to be more evenly distributed between the longitudinal and lateral paths, preventing the beams from bending during collisions and solving the problem of insufficient deformation resistance of traditional beams.

[0054] like Figure 6 As shown, the cross-section of the threshold 5 is a multi-cavity structure, forming multiple independent small chambers inside the threshold 5. The multi-cavity structure can absorb lateral collision energy through the sequential collapse of each chamber, extending the impact time. At the same time, the multi-cavity structure improves the overall stiffness of the threshold 5, making it more stable when transmitting lateral forces to the upper and lower crossbeams 6, avoiding force transmission interruption caused by excessive deformation of the threshold 5 itself, and solving the problems of low moment of inertia and poor bending performance of traditional C-shaped cross-section thresholds 5.

[0055] The front floor structure also includes slide rail assembly 9, such as Figure 8 , Figure 12 , Figure 13 , Figure 14 As shown, the slide rail assembly 9 includes an upper cover plate 10, a mounting plate 12, and a reinforcing plate 11 arranged sequentially from top to bottom. The front part of the reinforcing plate 11 is connected to the front crossbeam 3, the middle part is connected to the rear crossbeam 4, the outer side of the rear part is connected to the sill 5, and the inner side is connected to the bottom plate body. The mounting plate 12 is located on the reinforcing plate 11 and a cavity structure is provided between the two. The upper cover plate 10 is installed on the reinforcing plate 11 and the mounting plate 12, and forms a flat floor surface with the floor body 8.

[0056] The reinforcing plate 11 is connected to the front crossbeam 3, rear crossbeam 4, sill 5, and base plate body to form a stable support structure. The cavity between the mounting plate 12 and the reinforcing plate 11 can accommodate components without affecting the overall integrity of the floor. The sandwich structure of the slide rail assembly 9 ensures installation accuracy and, while maintaining the seat's sliding function, does not compress the battery installation space, thus solving the problems of traditional slide rails occupying battery space and having poor installation accuracy.

[0057] The front floor structure also includes a seat mounting structure 7, which is a box-shaped welded component, installed on the floor body 8 or the upper crossbeam, and connected to the lower crossbeam 6 or the rear crossbeam 4.

[0058] like Figure 7As shown, the seat mounting structure 7 adopts a box-shaped structure, which improves the rigidity of the seat mounting point: the force on the seat is distributed to the lower crossbeam 6 or the rear crossbeam 4 through the box, avoiding deformation of the mounting point caused by local stress concentration; the closed structure reduces the transmission of vibration between the seat and the body, reduces the resonance amplitude, and improves NVH performance; the connection with the body frame enhances the overall structure's cooperative load-bearing capacity, which can reduce the intrusion of the passenger compartment caused by the deformation of the seat mounting structure 7 during a collision, thus solving the problem of insufficient rigidity of the traditional seat mounting structure 7.

[0059] The front longitudinal beam 1, the middle channel 2, and the front crossbeam 3 form three positive force transmission paths, while the sill 5, the upper crossbeam, and the lower crossbeam 6 form three lateral force transmission paths, together forming a three-dimensional protective frame surrounding the battery pack.

[0060] In a frontal collision, the forward path disperses energy through the front longitudinal beam 1 and the central channel 2 to the front crossbeam 3, preventing overload on a single path. In a side collision, the lateral path, through the coordinated action of the sill 5, upper crossbeam, and lower crossbeam 6, transfers energy to other parts of the vehicle body. The three-dimensional protective frame formed by both surrounds the battery pack, dispersing the collision force from multiple directions, reducing the impact force directly acting on the battery, and solving the problems of a single force transmission path and battery susceptibility to compression in traditional structures.

[0061] Specifically:

[0062] The floor body 8 adopts a flat plate structure, such as Figure 9 As shown, the front part connects to the front compartment, the rear part connects to the rear floor, and the left and right sides each connect to the threshold 5; the upper and lower parts are equipped with multiple horizontal beam structures, and multiple longitudinal beam reinforcing ribs are provided.

[0063] The front longitudinal beam 1 is set on the floor body structure and is spot-welded to the floor body 8. Its front part is connected to the front compartment reinforcement structure, which can be done by bolting or welding. Its rear part is connected to the front cross beam 3, which can be done by bolting or welding. Its main cross section is M-shaped. The material is selected as high-strength plate with a yield greater than 600MPa or hot-formed steel plate, which is achieved by stamping or TRB. There is a front longitudinal beam 1 on each side.

[0064] The central channel 2 is located on the floor body structure and is connected to the floor body 8 by spot welding. Its front part is connected to the front compartment reinforcement structure, which can be done by bolting or welding. Its rear part is connected to the front crossbeam 3, which can be done by bolting or welding. Its main cross section is M-shaped. The material is selected as high-strength plate with a yield greater than 600MPa or hot-formed steel plate, which is achieved by stamping or TRB. This structure is located at the Y0 position of the vehicle body.

[0065] The front longitudinal beam 1 and the middle channel 2 together form three paths to transfer energy to the front cross beam 3, which can effectively disperse the energy of a frontal collision, ensure the integrity of the structure after the collision, and effectively protect the occupants and the battery.

[0066] The front longitudinal beam 1 and the floor body 8 form a closed M-shaped cavity structure. Compared with the traditional Z-shaped or C-shaped structure, the cross-sectional moment of inertia of this cavity structure is increased by about 30%, which can significantly improve the local stiffness mode and the stiffness mode of the body frame.

[0067] The front crossbeam 3 is set on the floor body and connected to the left and right sides, the side B-columns and the sill 5. The connection method can be spot welding or screwing. The lower part is connected to the floor body 8 and the lower crossbeam 6. The connection method can be spot welding or laser welding. The material is selected as high-strength plate with a yield greater than 780MPa or hot-formed steel plate, and the connection is achieved by stamping or rolling.

[0068] The rear crossbeam 4 is set on the floor body and connected to the left and right sides and the threshold 5. The connection method can be spot welding or screw connection. The lower part is connected to the floor body 8 and the lower crossbeam 6. The connection method can be spot welding or laser welding. The material is selected as high strength plate with yield greater than 780MPa or hot-formed steel plate, and the connection is achieved by stamping or roll forming.

[0069] The lower crossbeam 6 is installed under the floor body 8, and there are at least three of them. It is connected to the threshold 5 on the left and right sides by spot welding or screwing. The upper part is connected to the floor body 8 and the upper crossbeam by spot welding or laser welding. The material is selected as high-strength plate with a yield strength greater than 780MPa or hot-formed steel plate, and the process is achieved by stamping or roll forming.

[0070] The front crossbeam 3, rear crossbeam 4, and lower crossbeam 6 form three lateral force transmission paths, which can effectively disperse the energy of side collisions, ensure the integrity of the structure after a collision, and effectively protect the occupants and the battery.

[0071] The front crossbeam 3, floor body 8, and lower crossbeam 6 form a closed H-shaped cross-section cavity structure. This cavity structure can significantly improve the local stiffness mode and the stiffness mode of the body frame, improve the stability of the structure, and is not easy to bend during a collision, thus playing a very important role in protecting the battery and occupants.

[0072] The front of the door sill 5 is connected to the vertical plate of the A-pillar, and the rear is connected to the C-pillar and the rear longitudinal beam. The connection method is screwing or riveting. The inside of the door sill is connected to the upper crossbeam and the lower crossbeam 6. The connection method is screwing or riveting.

[0073] The door sill 5 is made of aluminum alloy with a nine-square grid-shaped cross-section. Its multi-cavity design forms a three-dimensional support frame that effectively disperses impact force during a collision. The internal grid structure collapses in stages, extending the collision buffer time. Furthermore, aluminum alloy has a low density, which reduces the vehicle's weight compared to traditional steel door sills, improving fuel economy or the driving range of electric vehicles.

[0074] The seat mounting structure 7 can be installed on the floor body 8 or the upper crossbeam, and is achieved by spot welding. It is a self-welding box structure, which is connected to the lower crossbeam 6. The seat rear mounting structure is a self-welding box structure, which is connected to the rear crossbeam 4.

[0075] The seat mounting box structure has good stability and high local stiffness. The closed structure forms a multi-directional force surface, which effectively improves NVH performance and plays a good role in creating a comfortable and quiet driving environment. In side collisions, the traditional Z-shaped crossbeam structure is prone to fracture due to stress concentration at the right angle. This closed structure greatly increases the resistance to deformation and can reduce the potential risk of the upper crossbeam tearing during a collision, which could lead to battery compression.

[0076] The slide rail assembly 9 consists of three parts: a reinforcing plate 11, a mounting plate 12, and a top cover plate 10. The front of the reinforcing plate 11 is connected to the front crossbeam 3, the middle to the rear crossbeam 4, the outer rear end to the sill 5, and the inner rear end to the floor body 8. The connection method is spot welding. The mounting plate 12 is located on top of the reinforcing plate 11, and a cavity structure is provided between the mounting plate 12 and the reinforcing plate 11. The top cover plate 10 is installed on the reinforcing plate 11 and the mounting plate 12, which can be achieved by screwing or riveting. It forms a flat floor surface with the floor body 8. This structural form can improve structural stability and durability, and does not occupy battery arrangement space, providing a flat floor surface.

[0077] The side impact design of this invention also adopts a multi-path energy transfer architecture, forming three main side force transmission paths through the sill 5, front crossbeam 3, rear crossbeam 4 and lower crossbeam 6. The sill 5 is made of nine-square aluminum alloy material, achieving a weight reduction effect of 20% to 25%, which not only ensures structural integrity but also realizes the step-by-step collapse function, extending the collision buffer time by more than 30 milliseconds and dispersing 85% of the collision impact force. The lower crossbeam 6 and the upper crossbeam are connected to form a continuous closed cavity, constructing a three-dimensional protective frame around the battery pack. The multi-directional force-bearing surface design reduces the risk of collision squeezing of the battery by 60%.

[0078] The seat mounting structure 7 of this invention adopts a box-shaped structure design, with a static stiffness of 2000-2500 N·m, which is 30% to 50% higher than that of traditional structures. It reduces the amplitude under resonance conditions by 40%, significantly improving NVH performance.

[0079] The side door slide rail assembly 9 of the present invention adopts a sandwich structure with an accuracy within ±0.5mm, which ensures installation accuracy without occupying battery placement space.

[0080] Example 2

[0081] When electric MPVs encounter non-standard collision conditions, such as 40% offset collisions or 30° oblique side collisions, the fixed force transmission path is prone to load imbalance in complex collisions. For example, in an offset collision, one side of the path may break due to overload. Traditional structures cannot detect the collision type in real time, resulting in low energy distribution efficiency. The risk of battery crushing increases non-linearly with the collision angle, and there are blind spots in static protection.

[0082] Based on this, this embodiment proposes a method for dynamic control of the force transmission path of the front floor structure, including:

[0083] Acquire acceleration data and vehicle deflection angle during a vehicle collision;

[0084] The collision resultant force direction angle is calculated based on acceleration components, and the collision type is identified by combining the vehicle body deflection angle.

[0085] Real-time detection of deformation parameters at key points of the three force transmission paths, and calculation of load rate for each path;

[0086] Based on the collision type and path load rate deviation, a current control command is output to the intelligent material actuator at the force transmission path connection point to change the damping characteristics of the connection point.

[0087] Acquiring acceleration data and vehicle body deflection angle during a collision provides a foundation for collision type identification; calculating the resultant force direction angle based on acceleration components and combining it with the deflection angle can accurately determine the direction and type of collision; detecting deformation parameters at key points in the force transmission path and calculating the load rate allows for real-time monitoring of the force state of each path; outputting current control commands to the intelligent material actuator to change damping characteristics can dynamically adjust the energy absorption capacity of the path.

[0088] This method enables dynamic control of the force transmission path: collision type identification provides a basis for load distribution, load rate calculation reflects the real-time status of the path, and current control commands adjust the path stiffness as needed. In non-standard collisions, it avoids load imbalance in fixed paths, improves energy absorption efficiency, and solves the problem of poor adaptability of traditional static paths in complex collisions.

[0089] Furthermore, the collision type identification includes: when both the resultant force direction angle and the vehicle body deflection angle are within the preset standard collision range, it is determined to be a standard frontal collision; when the resultant force direction angle exceeds the standard collision range but is less than the preset threshold, it is determined to be an offset collision; when the vehicle body deflection angle exceeds the preset threshold, it is determined to be an oblique collision.

[0090] By defining preset ranges for the resultant force direction angle and vehicle body deflection angle, standard frontal collisions, offset collisions, and oblique collisions are categorized, making collision type identification more targeted. Different collision types correspond to different load distribution strategies: in a standard frontal collision, the focus is on load balancing along the forward path; in an offset collision, backup paths need to be activated to share the load on one side; and in an oblique collision, more paths need to be mobilized to share the load. This tiered strategy avoids misjudgments caused by a single threshold, ensuring that control commands match the physical characteristics of the collision.

[0091] Furthermore, the output current control command includes: when the load rate of a single path is detected to exceed a set threshold, increasing the current of the actuator corresponding to the low-load path to improve its stiffness.

[0092] By adjusting the shear modulus of the actuator using current, the low-load path can absorb more energy, preventing the high-load path from breaking due to overload. This dynamic adjustment responds quickly and can optimize energy distribution in real time during a collision, ensuring the integrity of the force transmission path and solving the risk of path breakage caused by the inability of traditional structures to adjust in real time.

[0093] Detailed steps:

[0094] Step 1: Real-time collision type identification. The collision mode is identified within 10ms of a collision, providing input parameters for path allocation.

[0095] 1.1 Install a collision sensor network: Three triaxial acceleration sensors are evenly arranged inside the front bumper to measure the initial collision acceleration vector (ax, ay, az); one angle sensor is installed at the base of each of the left and right A-pillars to measure the vehicle body deflection angle θ.

[0096] 1.2 Collision Mode Classification: Calculation of the Direction Angle of the Resultant Collision Force:

[0097] ;

[0098] Where ax: X-axis acceleration component, ay: Y-axis acceleration component.

[0099] Collision types are classified according to α and θ: if |α| ≤ 15° and |θ| ≤ 5°, it is classified as a standard frontal collision; if 15° < |α| ≤ 45°, it is classified as an offset collision; if |θ| > 10°, it is classified as an oblique collision.

[0100] Step 2: Dynamic load distribution of force transmission paths: Adjust the load ratio of the three force transmission paths based on collision type and real-time deformation data.

[0101] 2.1 Deploy the strain monitoring unit:

[0102] Micro-strain gauges were attached to key points along the three main force transmission paths: the web of the M-shaped cavity in the front longitudinal beam (strain gauges S1-S2), the side wall of the third grid chamber from the outside to the inside of the vehicle at the nine-grid threshold section (strain gauges S3-S4), and the corner of the H-shaped crossbeam (strain gauges S5-S6). The sampling frequency was 1kHz, and the micro-strain value ε was measured.

[0103] 2.2 Calculate path load rate:

[0104] Define the real-time load rate of the path:

[0105] ;

[0106] Where, ε i : No. i Path strain value, ε i,max : The strain corresponding to the yield limit of a material.

[0107] 2.3 Dynamic Allocation Algorithm:

[0108] Constructing a fuzzy control rule base:

[0109]

[0110] Output adjustment command: Increase the damping coefficient of the low-load path, as in step 3.

[0111] Step 3: Material dynamic response execution: By changing the material damping characteristics, a soft switching of the energy path is achieved.

[0112] 3.1 Implanting intelligent material actuators: Fill the connection points of the force transmission path with magnetorheological elastomer (MRE), model: LordCorpMRF-132DG, shear modulus range 50~100kPa; installation positions: front longitudinal beam-front crossbeam joint (actuator E1), sill-lower crossbeam interface (actuator E2).

[0113] 3.2 Real-time damping control: Based on the output command in step 2.3, apply current I to the actuator:

[0114] ;

[0115] Wherein, Kp is the proportional coefficient, taken as 0.5A / %, and for every 1% increase in load rate deviation, 0.5A of current needs to be injected into the MRE actuator to improve stiffness. λ high Maximum load rate, λ low Minimum load rate. As current I increases, the MRE shear modulus rises, path stiffness improves, and more energy is absorbed.

[0116] The adaptive force transmission path dynamic control system and method under multimodal collision conditions improves collision adaptability, reduces unilateral path load during offset collisions, and lowers the risk of fracture and battery compression during oblique collisions. It shortens the time from collision recognition to path adjustment, making it faster than the vehicle body deformation initiation time, and improves energy absorption efficiency compared to static paths.

[0117] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. A front floor structure for an electric vehicle, characterized in that, It includes a floor body, a middle channel, front longitudinal beams, an upper cross beam, a lower cross beam and door sills; The middle channel and the front longitudinal beams are longitudinally arranged on the top surface of the floor body. The middle channel is located in the middle, and the front longitudinal beams are located on the left and right sides of the middle channel; The upper cross beam is transversely arranged on the top surface of the floor body and its two ends are connected to the door sills. The upper cross beam includes a front cross beam and a rear cross beam. The front cross beam is connected to the rear ends of the middle channel and the front longitudinal beams; The lower cross beam is transversely arranged on the bottom surface of the floor body and its two ends are connected to the door sills. There are at least three lower cross beams. Two of the lower cross beams are respectively located on the bottom sides of the front cross beam and the rear cross beam. The front cross beam and the rear cross beam respectively form a closed cavity structure with the corresponding lower cross beams and the floor body; It further includes a slide rail assembly. The slide rail assembly includes an upper cover plate, a mounting plate and a reinforcing plate which are arranged successively from top to bottom. The front part of the reinforcing plate is connected to the front cross beam, the middle part is connected to the rear cross beam, the outer side of the rear part is connected to the door sill, and the inner side is connected to the floor body; The mounting plate is located above the reinforcing plate and there is a cavity structure between them; The upper cover plate is mounted on the reinforcing plate and the mounting plate, and forms a flat floor surface with the floor body.

2. The front floor structure for electric vehicles as described in claim 1, characterized in that: The cross sections of the middle channel and the front longitudinal beams are both M-shaped closed cavity structures, and the middle parts of the top surfaces of the middle channel and the front longitudinal beams are recessed downward; 3. The front floor structure for electric vehicles as described in claim 1, characterized in that: The front cross beam, the rear cross beam and the corresponding lower cross beams and the floor body form a closed cavity structure in the shape of a Chinese character "ri"; 4. The front floor structure for electric vehicles as described in claim 1, characterized in that: The cross section of the door sill is a multi-cavity structure; 5. The front floor structure for electric vehicles as described in claim 1, characterized in that: It further includes a seat mounting structure. The seat mounting structure is a box-shaped welded part, which is arranged on the floor body or the upper cross beam and is connected to the lower cross beam or the rear cross beam; 6. The front floor structure for electric vehicles as described in claim 1, characterized in that: The front longitudinal beams, the middle channel and the front cross beam constitute three forward force transmission paths, and the door sills, the upper cross beam and the lower cross beam constitute three lateral force transmission paths, jointly forming a three-dimensional protection framework around the battery pack; 7. A method for dynamic control of the force transmission path in the front floor structure of an electric vehicle as described in any one of claims 1-6, characterized in that, It includes: Obtaining the acceleration data and the body deflection angle during vehicle collision; Calculating the collision resultant force direction angle based on the acceleration components, and identifying the collision type in combination with the body deflection angle; Real-time detecting the deformation parameters of the key points of the three force transmission paths and calculating the load rate of each path; According to the collision type and the path load rate deviation, outputting a current control instruction to the intelligent material actuator at the force transmission path connection point to change the damping characteristic of the connection point; 8. The dynamic control method for force transmission path as described in claim 7, characterized in that: The identifying the collision type includes: when both the resultant force direction angle and the body deflection angle are within the preset standard collision range, it is determined as a standard frontal collision; when the resultant force direction angle exceeds the standard collision range but is less than the preset threshold, it is determined as an offset collision; when the body deflection angle exceeds the preset threshold, it is determined as an oblique collision; 9. The dynamic control method for force transmission path as described in claim 7, characterized in that: The outputting the current control instruction includes: when it is detected that the load rate of a single path exceeds the set threshold, increasing the current of the actuator corresponding to the low-load path to improve its stiffness.

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