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

Abstract

The invention relates to the technical field of automobile body structures, in particular to a front floor structure for an electric vehicle and a dynamic regulation and control method for a force transmission path. The front floor structure comprises a bottom plate body, a middle channel, a front longitudinal beam, an upper cross beam, a lower cross beam and a doorsill. The middle channel and the front longitudinal beams are longitudinally arranged on the top face of the bottom plate body, the middle channel is located in the middle, and the front longitudinal beams are located on the left side and the right side of the middle channel. The upper cross beam is transversely arranged on the top surface of the bottom plate body, two ends of the upper cross beam are connected with the doorsill, and the upper cross beam comprises a front cross beam and a rear cross beam; the number of the lower cross beams is at least three, two of the lower cross beams are located on the bottom side of the front cross beam and the bottom side of the rear cross beam respectively, and the front cross beam and the rear cross beam form a closed cavity structure with the corresponding lower cross beams and the floor body respectively. According to the invention, the problems of single and discontinuous force transmission path and the like are solved, the moment of inertia of section is increased, and the battery extrusion probability is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of automobile body structure, and particularly relates to a front floor structure for an electric vehicle and a force transmission path dynamic regulation method. BACKGROUND

[0002] The front floor structure is one of the core components of the vehicle body framework, located at the bottom of the passenger compartment, connected to the engine compartment or front spare compartment in front, connected to the side wall on the left and right, and connected to the rear floor in the rear. Its main functions include supporting the passenger and component load, maintaining the stiffness and modal characteristics of the vehicle body, controlling noise vibration (NVH), absorbing and transmitting energy in a collision to protect the safety of the passengers, and, in an electric vehicle, particularly crucially, protecting the bottom-mounted power battery pack from collision extrusion.

[0003] The traditional front floor structure is usually composed of a floor panel, longitudinal beams, transverse beams, and a rocker, etc. The design of the structure directly affects the crash safety and structural performance of the vehicle. The middle channel of the longitudinal beam is usually located at the position of the longitudinal center line of the vehicle body and protrudes. The left / right upper transverse beam adopts a segmented structure. In terms of crash safety, such a structure mainly relies on the established force transmission path, such as the front longitudinal beam and the middle channel, to transmit the energy of the frontal collision to the transverse beam structure. The rocker structure is usually made of steel and has a C-shaped or similar simple cross-sectional structure.

[0004] Therefore, the existing front floor structure has the following technical problems: Firstly, the single frontal and side force transmission path design is prone to cause local path overload and fracture or structural instability under crash conditions, which cannot effectively disperse impact energy, resulting in an increase in the deformation of the passenger compartment. At the same time, the discontinuity of the force transmission path and the insufficient moment of inertia of the cross section increase the risk of bending or breaking of the structure in a collision, which may further cause the battery pack to be extruded, posing a safety hazard.

[0005] Secondly, the traditional structure has a weak three-dimensional protective frame around the battery area, especially the side and bottom protection. The rocker structure has poor bending performance, and the transverse beam structure is prone to bending or local tearing in a collision, making it difficult to effectively resist the threat of the battery pack from collisions in all directions.

[0006] Thirdly, the rocker structure is heavy, which is not conducive to the lightweight demand of the electric vehicle and the improvement of the range. When the traditional structure is lightened, it is often difficult to ensure sufficient stiffness, modal, and crash safety, especially in terms of battery protection.

[0007] Finally, the traditional structure in the seat mounting point area is a few-shaped beam, which has insufficient stiffness and is prone to large deformation and vibration under dynamic load, affecting the NVH performance and ride comfort, and the connection part is prone to failure due to stress concentration in a collision. SUMMARY

[0008] In view of the deficiencies of the prior art, the purpose of the embodiments of the present application is to provide an electric MPV front floor structure with a multi-path efficient force transmission architecture, a high-rigidity closed cavity cross-section design, a lightweight multi-cavity threshold, all-around battery protection, and a compact slide rail assembly, so as to improve the body rigidity, modal, collision safety, and lightweight level.

[0009] In order to achieve the above-mentioned purpose, the embodiments of the present application provide the following technical solutions: A front floor structure for an electric vehicle, comprising a bottom plate body, a middle channel, a front longitudinal beam, an upper cross beam, a lower cross beam, and a threshold; the middle channel and the front longitudinal beam are arranged on the top surface of the bottom plate body in the longitudinal direction, the middle channel is located in the middle, and the front longitudinal beam is located on the left and right sides of the middle channel; the upper cross beam is arranged on the top surface of the bottom plate body in the transverse direction and connected to the threshold at both ends, the upper cross beam comprises a front cross beam and a rear cross beam, and the front cross beam is connected to the rear end of the middle channel and the front longitudinal beam; the lower cross beam is arranged on the bottom surface of the bottom plate body in the transverse direction and connected to the threshold at both ends, the lower cross beam is at least three, two of which are located on the bottom side of the front cross beam and the rear cross beam respectively, and the front cross beam, the rear cross beam, and the corresponding lower cross beam and the bottom plate body form a closed cavity structure.

[0010] Optionally, the cross section of the middle channel and the front longitudinal beam is an M-shaped closed cavity structure, and the middle part of the top surface of the middle channel and the front longitudinal beam is recessed downward.

[0011] Optionally, the front cross beam, the rear cross beam, and the corresponding lower cross beam and the bottom plate body form a closed cavity structure in the shape of a Chinese character 'Ri'.

[0012] Optionally, the cross section of the threshold is a multi-cavity structure.

[0013] Optionally, it further comprises a slide rail assembly, the slide rail assembly comprises 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 threshold, and the inner side is connected to the bottom plate body; the mounting plate is located above the reinforcing plate and a cavity structure is arranged between the two; the upper cover plate is mounted on the reinforcing plate and the mounting plate, and forms a flat floor surface with the bottom plate body.

[0014] Optionally, it further comprises a seat mounting structure, the seat mounting structure is a box-shaped welded part, arranged on the bottom plate body or the upper cross beam, and connected to the lower cross beam or the rear cross beam.

[0015] Optionally, the front longitudinal beam, the middle channel, and the front cross beam form three forward force transmission paths, the threshold, the upper cross beam, and the lower cross beam form three lateral force transmission paths, and together form a three-dimensional protective frame surrounding the battery pack.

[0016] The embodiments of the present application also provide a force transmission path dynamic regulation method for the front floor structure for an electric vehicle. Obtain acceleration data and body deflection angle when the vehicle collides; Calculate the collision resultant force direction angle based on the acceleration component, and identify the collision type in combination with the body deflection angle; Real-time detect the deformation parameters of the key points of the three force transmission paths, and calculate the load rate of each path; According to the collision type and the deviation of the path load rate, the current control instruction is output to the intelligent material actuator connected to the force transmission path to change the damping characteristics of the connection point.

[0017] Optionally, the collision type identification includes: when 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 a 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.

[0018] Optionally, the current control instruction output includes: when it is detected that the load rate of a single path exceeds a set threshold, the current of the actuator corresponding to the low load path is increased to improve its stiffness.

[0019] One or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages: 1. In the front floor structure of the present application, the bottom body serves as a basic load-bearing component, connecting the front and rear structures and the left and right door sills, and providing installation reference for other components. The middle channel is located in the middle, the front longitudinal beams are located on both sides of the middle channel and are arranged in the longitudinal direction, and the upper and lower transverse beams are transversely arranged to form a longitudinal and transverse interlaced frame structure. The front transverse beam connects the middle channel and the rear end of the front longitudinal beam, and the two lower transverse beams correspond to the bottom sides of the front and rear transverse beams respectively, so that the front transverse beam and the rear transverse beam form a closed cavity with the corresponding lower transverse beam and the bottom body respectively. The front floor structure cooperatively arranges the longitudinal and transverse components to build a multi-directional force transmission foundation: the middle channel and the front longitudinal beam are connected to the front transverse beam to form a direct force transmission path, and the door sill and the upper and lower transverse beams are connected to form a lateral force transmission path; compared with the traditional open or simple cross section, the closed cavity structure improves the moment of inertia and the bending resistance of the structure, and reduces local deformation during collision. At the same time, the components around the battery mounting area form a ring-shaped layout, which provides a structural basis for battery protection. Compared with the traditional segmented structure, this structure solves the problems of single and discontinuous force transmission path and improves the structural integrity; the closed cavity increases the cross-sectional moment of inertia, reducing the risk of transverse beam bending; the multi-transverse beam layout builds a three-dimensional protection area around the battery pack, reducing the probability of battery extrusion.

[0020] 2. The cross-section of the threshold is a multi-cavity structure, forming multiple independent small cavities inside the threshold. The multi-cavity can absorb side collision energy by sequentially collapsing each cavity, prolonging the collision force action time; at the same time, the multi-cavity structure improves the overall stiffness of the threshold, making it more stable when transmitting lateral force to the upper and lower cross beams, avoiding the transmission of force interruption caused by excessive deformation of the threshold itself, and solving the problem of low inertia moment and poor bending resistance of the traditional C-shaped cross-section threshold.

[0021] 3. The seat mounting structure adopts a box-shaped structure, which improves the stiffness of the seat mounting point: the force on the seat is dispersed to the lower cross beam or the rear cross beam through the box body, avoiding deformation of the mounting point caused by local stress concentration; the closed structure reduces the transmission of vibration between the seat and the vehicle body, reduces the resonance amplitude, and improves the NVH performance; the connection with the vehicle body frame enhances the cooperative bearing capacity of the overall structure, which can reduce the intrusion of the passenger compartment caused by the deformation of the seat mounting structure during collision, and solves the problem of insufficient stiffness of the traditional seat mounting structure.

[0022] 4. The dynamic regulation method of the force transmission path provides a basis for load distribution through collision type identification, the load rate calculation reflects the real-time state of the path, and the current control instruction adjusts the path stiffness as needed. In non-standard collisions, load imbalance of fixed paths can be avoided, and energy absorption efficiency can be improved, solving the problem of poor adaptability of traditional static paths in complex collisions.

[0023] The advantages of the additional aspects of the application will be given in the following description, some of which will become apparent from the following description, or will be understood through practice of the application. BRIEF DESCRIPTION OF DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only some embodiments described in the present application, and for those skilled in the art, other drawings can also be obtained without creative labor on the basis of these drawings. In addition, the size or distance between each other is exaggerated to show the position of each component, and the schematic diagram is only used for illustration.

[0025] Figure 1 is a schematic diagram of the front floor structure provided by the embodiment of the present application; Figure 2 is an exploded schematic diagram (top surface) of the front floor structure provided by the embodiment of the present application; Figure 3 is an exploded schematic diagram (bottom surface) of the front floor structure provided by the embodiment of the present application; Figure 4 is a schematic diagram of the cross-section at Y0 of the floor structure provided by the embodiment of the present application; Figure 5It is the schematic view of the floor structure X section provided by the embodiment of the present application. Figure 6 It is the schematic view of the threshold provided by the embodiment of the present application. Figure 7 It is the schematic view of the seat mounting structure provided by the embodiment of the present application. Figure 8 It is the schematic view of the slide rail assembly provided by the embodiment of the present application. Figure 9 It is the installation effect picture of the front floor structure on the whole vehicle provided by the embodiment of the present application. Figure 10 It is the top surface effect picture of the front floor structure provided by the embodiment of the present application. Figure 11 It is the bottom surface effect picture of the front floor structure provided by the embodiment of the present application. Figure 12 It is the installation effect picture of the reinforcing plate provided by the embodiment of the present application. Figure 13 It is the installation effect picture of the mounting plate provided by the embodiment of the present application. Figure 14 It is the installation effect picture of the upper cover plate provided by the embodiment of the present application. In the figure: 1, front longitudinal beam; 2, middle channel; 3, front cross beam; 4, rear cross beam; 5, threshold; 6, lower cross beam; 7, seat mounting structure; 8, floor body; 9, slide rail assembly; 10, upper cover plate; 11, reinforcing plate; 12, mounting plate. DETAILED DESCRIPTION It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the present application. Unless otherwise indicated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. Furthermore, it should be understood that the use of the terms "include", "includes", "including", and / or "comprising" in this specification is intended to mean that the indicated feature, step, operation, device, component, and / or combinations thereof is present, but not excluding the presence of one or more other features, steps, operations, devices, components, and / or combinations thereof.

[0026] Example 1 As Figure 1 , Figure 2 , Figure 3 , Figure 10 , Figure 11As shown, this embodiment proposes a front floor structure for an electric vehicle, including a floor body, a middle channel 2, a front longitudinal beam 1, an upper cross beam, a lower cross beam 6 and a door sill 5; the middle channel 2 and the front longitudinal beam 1 are longitudinally arranged on the top surface of the floor body, the middle channel 2 is located in the middle, and the front longitudinal beam 1 is located on the left and right sides of the middle channel 2; the upper cross beam is transversely arranged on the top surface of the floor body and connected to the door sill 5 at both ends, the upper cross beam includes a front cross beam 3 and a rear cross beam 4, the front cross beam 3 connects the middle channel 2 and the rear end of the front longitudinal beam 1; the lower cross beam 6 is transversely arranged on the bottom surface of the floor body and connected to the door sill 5 at both ends, there are at least three lower cross beams 6, two of which are respectively located on the bottom sides of the front cross beam 3 and the rear cross beam 4, and the front cross beam 3 and the rear cross beam 4 respectively form a closed cavity structure with the corresponding lower cross beam 6 and the floor body 8.

[0027] The floor panel body serves as the foundational support, upon which a central channel 2 and front longitudinal beams 1 are positioned. Central channel 2 is located in the center, with front longitudinal beams 1 flanking each side, forming a stable longitudinal structure. The upper crossbeams, comprising front and rear crossbeams 3 and 4, run across the top of the floor panel body and connect to the door sill 5. The lower crossbeam 6, located on the bottom of the floor panel body, connects to the door sill 5 and forms a closed cavity with the upper crossbeam and floor panel body 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 deformation in the passenger compartment, and protecting the safety of the vehicle occupants. The performance is particularly strong in battery protection.

[0028] like Figure 5 As shown, the cross-section of the central tunnel 2 and front longitudinal beam 1 both feature an M-shaped closed cavity structure, with the center of the top surface of each recessed downward. This M-shaped structure increases the moment of inertia by approximately 30% compared to a traditional C-shaped cross-section, significantly enhancing bending resistance. In the event of a collision, it effectively resists bending moments, prevents component deformation, maintains structural integrity, and ultimately improves the vehicle body's modal stiffness.

[0029] like Figure 4 As shown, the front and rear crossbeams 3 and 4, together with the corresponding lower crossbeams 6 and the floor panel 8, form a "日"-shaped closed cavity structure. The "日"-shaped closed cavity structure is enclosed by the front and rear crossbeams 3 and 4, respectively, together with the corresponding lower crossbeams 6 and the floor panel 8, forming a cavity with two upper and lower layers separated in the middle.

[0030] The multi-partition design of the "日"-shaped cavity allows the force to be dispersed and transmitted through multiple cavity walls when the structure is subjected to lateral force, reducing stress concentration in a single direction; after being connected to the longitudinal component of the M-shaped cross-section, the longitudinal and transverse closed cavities support each other to form a three-dimensional rigid frame, so that the energy of frontal or side collisions can be more evenly distributed between the longitudinal and transverse paths, avoiding bending of the beam during a collision, and solving the problem of insufficient deformation resistance of traditional beams.

[0031] As shown in Figure 6 The cross section of the threshold 5 is a multi-cavity structure, forming multiple independent small cavities inside the threshold 5. The multi-cavity can absorb side collision energy by sequentially collapsing each cavity, prolonging the collision force action time; at the same time, the multi-cavity structure improves the overall stiffness of the threshold 5, making it more stable when transmitting lateral force to the upper and lower cross beams 6, avoiding the transmission of force being interrupted due to excessive deformation of the threshold 5 itself, and solving the problem of low moment of inertia and poor bending resistance of the traditional C-shaped cross section threshold 5.

[0032] The front floor structure also includes a slide rail assembly 9, as shown in Figure 8 、 Figure 12 、 Figure 13 、 Figure 14 The slide rail assembly 9 includes an upper cover plate 10, a mounting plate 12 and a reinforcing plate 11 arranged from top to bottom, the reinforcing plate 11 is connected to the front cross beam 3 at the front, connected to the rear cross beam 4 at the middle, connected to the threshold 5 at the rear outside, and connected to the bottom plate body at the inside; the mounting plate 12 is located above the reinforcing plate 11 and a cavity structure is provided between them; 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.

[0033] The reinforcing plate 11 is connected to the front cross beam 3, the rear cross beam 4, the threshold 5 and the bottom plate body, forming a stable support structure. The cavity between the mounting plate 12 and the reinforcing plate 11 can accommodate components without affecting the integrity of the floor. The sandwich structure of the slide rail assembly 9 ensures installation accuracy, ensures seat sliding function, does not compress battery installation space, and solves the problem of traditional slide rail occupying battery space and poor installation accuracy.

[0034] The front floor structure also includes a seat mounting structure 7, which is a box-shaped welded part, arranged on the floor body 8 or the upper cross beam, and connected to the lower cross beam 6 or the rear cross beam 4.

[0035] As shown in Figure 7 The seat mounting structure 7 adopts a box-shaped structure, which improves the stiffness of the seat mounting point: the force on the seat is dispersed to the lower cross beam 6 or the rear cross beam 4 through the box body, avoiding deformation of the mounting point caused by local stress concentration; the closed structure reduces the transmission of vibration between the seat and the vehicle body, reduces the resonance amplitude, and improves the NVH performance; the connection with the vehicle body frame enhances the cooperative bearing capacity of the overall structure, which can reduce the intrusion of the passenger compartment caused by the deformation of the seat mounting structure 7 in a collision, and solves the problem of insufficient stiffness of the traditional seat mounting structure 7.

[0036] The front longitudinal beam 1, the middle channel 2 and the front cross beam 3 form three positive force transmission paths, the threshold 5, the upper cross beam and the lower cross beam 6 form three lateral force transmission paths, which together form a three-dimensional protective frame around the battery pack.

[0037] In a frontal collision, the forward path disperses energy through the front longitudinal beam 1 and center tunnel 2 to the front cross member 3, preventing overload in a single path. In a side impact, the lateral path transfers energy to other parts of the vehicle body through the sill 5, upper cross member, and lower cross member 6. The three-dimensional protective framework formed by these two elements surrounds the battery pack, dispersing collision forces in multiple directions and reducing the impact force directly on the battery. This solves the problem of traditional structures with a single force transmission path and the battery being easily squeezed.

[0038] Specifically: The floor body 8 adopts a flat plate structure. Figure 9 As shown, the front part is connected to the front compartment, the rear part is connected to the rear floor, and the left and right parts are connected to the door sills 5; the upper and lower parts are both provided with multiple cross beam structures and multiple longitudinal beam reinforcement ribs.

[0039] The front longitudinal beam 1 is arranged 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 by screwing or welding; its rear part is connected to the front cross beam 3 by screwing or welding. Its main cross section is M-shaped, and the material is selected from high-strength plate or hot-formed steel plate with a yield strength greater than 600MPA, which is realized by stamping or TRB, and a front longitudinal beam 1 is set on each side.

[0040] The middle channel 2 is arranged 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 by screwing or welding; its rear part is connected to the front cross beam 3 by screwing or welding. Its main cross-section is M-shaped, and the material is selected from high-strength plate or hot-formed steel plate with a yield strength greater than 600MPA, and is realized by stamping or TRB. This structure is arranged at the Y0 position of the vehicle body.

[0041] The front longitudinal beam 1 and the center tunnel 2 form three paths to transfer energy to the front cross member 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; The front longitudinal beam 1 and the floor body 8 form a closed M-shaped cavity structure. Compared with the traditional M-shaped or C-shaped structure, the cross-sectional inertia moment of this cavity structure is increased by about 30%, which can greatly improve the local stiffness mode and the stiffness mode of the vehicle body frame.

[0042] The front crossbeam 3 is arranged on the floor body, and is connected to the side B-pillars and the door sill 5 on the left and right sides. 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 from high-strength plate with a yield strength greater than 780MPA or hot-formed steel plate, which is achieved by stamping or rolling.

[0043] The rear cross beam 4 is arranged on the floor body, and is connected with the left and right side doorsill 5 by spot welding or screwing; the lower part is connected with the floor body 8 and the lower cross beam 6 by spot welding or laser welding, and the material is selected to be a high-strength plate with a yield greater than 780 MPA or a hot-formed steel plate, and stamping or rolling is adopted.

[0044] The lower cross beam 6 is arranged below the floor body 8, and the number is greater than or equal to three, and the left and right sides are connected with the doorsill 5 by spot welding or screwing, and the upper part is connected with the floor body 8 and the upper cross beam by spot welding or laser welding, and the material is selected to be a high-strength plate with a yield greater than 780 MPA or a hot-formed steel plate, and stamping or rolling is adopted The front cross beam 3, the rear cross beam 4 and the lower cross beam 6 form three lateral force transmission paths, which can effectively disperse the side collision energy and ensure the integrity of the structure after the collision, effectively protecting the passengers and the battery.

[0045] The front cross beam 3, the floor body 8 and the lower cross beam 6 form a closed cross-shaped cross-section cavity structure, which can greatly improve the local stiffness mode and the stiffness mode of the vehicle body framework, improve the stability of the structure, and not easy to bend in the process of collision, play a very protective role for the battery and the passengers.

[0046] The front part of the doorsill 5 is connected with the A-pillar vertical plate, and the rear part is connected with the C-pillar and the rear longitudinal beam, and the connection mode is screwing or riveting, and the inner side is connected with the upper cross beam and the lower cross beam 6 by screwing or riveting.

[0047] The doorsill 5 is made of aluminum alloy material, and the main cross section is a nine-square grid shape, which forms a three-dimensional support frame through multi-cavity design, and can effectively disperse the impact force in the collision; the internal grid structure can gradually collapse to prolong the collision buffer time. And the aluminum alloy material has low density, compared with the traditional steel doorsill 5, it can reduce the weight of the vehicle body, improve the fuel economy or the endurance mileage of the electric vehicle.

[0048] The seat mounting structure 7 can be arranged on the floor body 8 or the upper cross beam, and is realized by spot welding, which is a self-welding box-shaped structure, and is connected with the lower cross beam 6, and the rear part of the seat mounting structure is a self-welding box-shaped structure, which is connected with the rear cross beam 4.

[0049] The seat mounting box-shaped structure has good stability and high local stiffness, and the closed structure forms a multi-directional stress surface, effectively improving the NVH performance, and playing a good role in the comfortable and quiet driving environment; the traditional cross-shaped structure beam structure is easy to break at the right angle turning part due to stress concentration in the side collision, and the closed structure form greatly increases the anti-deformation ability, which can reduce the local tearing of the upper cross beam in the process of collision, and reduce the potential risk of extruding the battery.

[0050] The slide rail assembly 9 is composed of three parts: a reinforcing plate 11, a mounting plate 12 and an upper cover plate 10. The reinforcing plate 11 is connected to the front cross beam 3 at the front part, connected to the rear cross beam 4 at the middle part, connected to the rocker 5 at the outer side of the rear part, connected to the floor body 8 at the inner side, and connected by spot welding. The mounting plate 12 is located above the reinforcing plate 11, and a cavity structure is arranged between the mounting plate 12 and the reinforcing plate 11. The upper cover plate 10 is mounted on the reinforcing plate 11 and the mounting plate 12, and can be achieved by screwing or riveting. It forms a flat floor surface with the floor body 8. This structure can improve the stability and durability of the structure, does not occupy the battery arrangement space, and can provide a flat floor surface.

[0051] The side collision design of the present application also adopts a multi-path energy transmission architecture. Three main side force transmission paths are formed by the rocker 5, the front cross beam 3, the rear cross beam 4 and the lower cross beam 6. The rocker 5 is made of nine-square aluminum alloy material, achieving 20% to 25% lightweight effect, ensuring structural integrity and realizing step-by-step collapse function, prolonging the collision buffer time by more than 30 milliseconds, and dispersing 85% of the collision impact force. The connection between the lower cross beam 6 and the upper cross beam forms a continuous closed cavity, which constructs a three-dimensional protective frame around the battery pack. The multi-directional stress surface design reduces the risk of collision and battery extrusion by 60%.

[0052] The seat mounting structure 7 of the present application adopts a box-shaped structure design, and its static stiffness reaches 2000-2500 N·m, which is 30% to 50% higher than that of the traditional structure, and reduces the amplitude under resonance conditions by 40%, greatly improving the NVH performance The side door slide rail assembly 9 of the present application adopts a sandwich structure, with an accuracy of ±0.5 mm, which ensures installation accuracy and does not occupy battery arrangement space.

[0053] Example 2 When the electric MPV encounters non-standard collision conditions, such as 40% offset collision and 30° oblique side collision, the fixed force transmission path is prone to load imbalance in complex collisions, such as unilateral path overload fracture in offset collision. The traditional structure cannot sense the collision type in real time, resulting in low energy distribution efficiency, and the risk of battery extrusion increases nonlinearly with the change of collision angle, and there is a blind area in static protection.

[0054] Therefore, the present embodiment proposes a force transmission path dynamic regulation method for a front floor structure, which comprises: obtaining acceleration data and body deflection angle when the vehicle collides; calculating the collision resultant force direction angle based on the acceleration component, and identifying the collision type in combination with the body deflection angle; real-time detection of deformation parameters of key points of three force transmission paths, and calculation of path load rate; According to the collision type and the path load rate deviation, the current control instruction is output to the intelligent material actuator of the connection point of the force transmission path to change the damping characteristics of the connection point.

[0055] The acceleration data and body deflection angle at the time of collision are obtained, providing a basis for collision type identification; the direction angle of the resultant force is calculated based on the acceleration components, and the deflection angle is combined, which can accurately determine the direction and type of the collision; the deformation parameters of the key points of the force transmission path are detected, and the load rate is calculated, which can master the stress state of each path in real time; the current control instruction is output to the intelligent material actuator to change the damping characteristics, which can dynamically adjust the energy absorption capacity of the path.

[0056] The method realizes dynamic regulation and control of the force transmission path: collision type identification provides a basis for load distribution, load rate calculation reflects the real-time state of the path, and current control instruction adjusts the stiffness of the path as needed. In non-standard collision, load imbalance of fixed path can be avoided, energy absorption efficiency can be improved, and the problem of poor adaptability of traditional static path in complex collision is solved.

[0057] Further, the collision type identification includes: when the direction angle of the resultant force and the body deflection angle are within the preset standard collision range, it is determined as a standard frontal collision; when the direction angle of the resultant force exceeds the standard collision range but is less than a 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.

[0058] By presetting the range of the direction angle of the resultant force and the body deflection angle, standard frontal collision, offset collision and oblique collision are divided, making the identification of collision type more targeted. Different collision types correspond to different load distribution strategies: in standard frontal collision, load balance of the forward path is emphasized, in offset collision, standby path needs to be activated to share unilateral load, and in oblique collision, more paths need to be mobilized to bear load. This hierarchical strategy avoids misjudgment caused by a single threshold and ensures that the control instruction matches the physical characteristics of the collision.

[0059] Further, the output current control instruction includes: when it is detected that the load rate of a single path exceeds a set threshold, the current of the actuator corresponding to the low load path is increased to improve its stiffness.

[0060] By adjusting the shear modulus of the actuator through current, the low load path can absorb more energy, and the high load path can be prevented from breaking due to overload. This dynamic adjustment responds quickly and can optimize energy distribution in real time during the collision process, ensuring the integrity of the force transmission path and solving the risk of path fracture caused by the inability of traditional structures to adjust in real time.

[0061] Detailed method steps: Step 1: Real-time identification of collision type, identify the collision mode within 10ms of collision occurrence to provide input parameters for path distribution.

[0062] 1.1 Install the collision sensing network: evenly distribute 3 three-axis acceleration sensors inside the front bumper, measure the initial acceleration vector (ax, ay, az) of the collision; install 1 angle sensor at the root of the left and right A-pillar, measure the body deflection angle θ.

[0063] 1.2 Collision mode classification: calculate the collision resultant force direction angle: ; Where ax: X-axis acceleration component, ay: Y-axis acceleration component.

[0064] According to α and θ, the collision type is divided: 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.

[0065] Step 2: Dynamic load distribution of force transmission path: based on the collision type and real-time deformation data, adjust the load proportion of the three force transmission paths.

[0066] 2.1 Arrange strain monitoring units: Paste micro-strain gauges at key points on the three main force transmission paths: at the M-shaped cavity web of the front longitudinal beam (strain gauges S1-S2), at the side wall of the third grid chamber of the nine-grid threshold section from the outside to the inside of the car (strain gauges S3-S4), at the corner of the day-shaped cross beam (strain gauges S5-S6), with a sampling frequency of 1 kHz, measuring micro-strain value ε.

[0067] 2.2 Calculate path load rate: Define the real-time load rate of the path: ; Where ε i : the strain value of the path, ε i,max : the strain corresponding to the material yield limit. i

[0068] 2.3 Dynamic distribution algorithm: Construct a fuzzy control rule base:

[0069] Output adjustment instructions: increase the damping coefficient of the low-load path, such as step 3.

[0070] Step 3: Dynamic response of materials: achieve soft switching of energy paths by changing material damping characteristics.

[0071] ​3.1 Implanting smart material actuators: Fill the force transmission path connection point with magneto-rheological elastomer (MRE), model: Lord Corp MRF-132DG, shear modulus range 50~100kPa; installation position: front longitudinal beam-front cross beam joint (actuator E1), threshold-under cross beam interface (actuator E2).

[0072] 3.2 Real-time damping regulation: According to the output instruction of step 2.3, apply current I to the actuator: ; Wherein, Kp is the proportional coefficient, taking 0.5A / %, and for every 1% increase in load rate deviation, 0.5A current needs to be injected into the MRE actuator to increase the stiffness. high : Maximum load rate, λ low : Minimum load rate. The current I increases, the MRE shear modulus rises, the path stiffness increases, and more energy is absorbed.

[0073] Through the adaptive force transmission path dynamic regulation system and method under multi-modal collision conditions, the collision adaptability is improved, the unilateral path load during offset collision is reduced, the risk of fracture and the risk of battery extrusion during oblique collision are reduced. The time from collision recognition to path adjustment is shortened, which is faster than the time of vehicle body deformation, and the energy absorption efficiency is improved compared with the static path.

[0074] Although the specific embodiments of the present application are described above in combination with the drawings, it is not a limitation on the protection scope of the present application. Those skilled in the art should understand that various modifications or changes made on the basis of the technical solutions of the present application without creative labor are still within the protection scope of the present application.

Claims

1. A front floor structure for an electric vehicle, characterized in that: It includes the floor body, center channel, front longitudinal beam, upper cross beam, lower cross beam and door sill; The middle channel and the front longitudinal beams are arranged on the top surface of the bottom plate body in the longitudinal direction, 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 crossbeam is arranged on the top surface of the bottom plate body in the transverse direction and connected to the door sills at both ends. The upper crossbeam includes a front crossbeam and a rear crossbeam. The front crossbeam connects the middle channel and the rear end of the front longitudinal beam. The lower cross beam is arranged horizontally on the bottom surface of the base plate body and connected to the door sills at both ends. There are at least three lower cross beams, two of which are located on the bottom sides of the front cross beam and the rear cross beam respectively. The front cross beam and the rear cross beam respectively form a closed cavity structure with the corresponding lower cross beam and the floor body.

2. The front floor structure for an electric vehicle according to claim 1, wherein: The cross sections of the central channel and the front longitudinal beam are both M-shaped closed cavity structures, and the middle portions of the top surfaces of the central channel and the front longitudinal beam are both recessed downward.

3. The front floor structure for an electric vehicle according to claim 1, wherein: The front cross beam, the rear cross beam, the corresponding lower cross beam and the floor body form a Japanese-shaped closed cavity structure.

4. The front floor structure for an electric vehicle according to claim 1, wherein: The cross section of the door sill is a multi-cavity structure.

5. The front floor structure for an electric vehicle according to claim 1, wherein: It also includes a slide rail assembly, which includes an upper cover plate, a mounting plate and a reinforcement plate arranged in sequence from top to bottom, the front of the reinforcement plate is connected to the front crossbeam, the middle is connected to the rear crossbeam, the rear outer side is connected to the door sill, and the inner side is connected to the bottom plate body; the mounting plate is located above the reinforcement plate and a cavity structure is provided between the two; the upper cover plate is installed on the reinforcement plate and the mounting plate, and forms a flat floor surface with the floor body.

6. The front floor structure for an electric vehicle according to claim 1, wherein: It also includes a seat mounting structure, which is a box-shaped welded part, arranged on the floor body or the upper crossbeam, and connected to the lower crossbeam or the rear crossbeam.

7. The front floor structure for an electric vehicle according to claim 1, wherein: The front longitudinal beam, the middle channel and the front cross beam constitute three forward force transmission paths, and the door sill, the upper cross beam and the lower cross beam constitute three lateral force transmission paths, together forming a three-dimensional protective frame surrounding the battery pack.

8. A method for dynamically controlling the force transmission path of a front floor structure of an electric vehicle according to any one of claims 1 to 7, characterized in that: include: Obtain acceleration data and vehicle body deflection angle during vehicle collision; Calculate the direction angle of the resultant collision force based on the acceleration component and identify the collision type based on the vehicle body deflection angle; Real-time detection of deformation parameters of key points of three force transmission paths and calculation of load rate of each path; According to the collision type and path load rate deviation, current control instructions are output to the smart material actuator at the connection point of the force transmission path to change the damping characteristics of the connection point.

9. The method for dynamic control of force transmission path according to claim 8, characterized in that: The collision type identification includes: when the resultant force direction angle and the vehicle body deflection angle are both 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 a 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.

10. The method for dynamic control of force transmission path according to claim 8, characterized in that: The output current control instruction includes: when it is detected that the load rate of a single path exceeds a set threshold, increasing the current of the actuator corresponding to the low-load path to improve its stiffness.

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