Off-road vehicle frame based on multifunctional fusion and variable stiffness topology and vehicle

Abstract

The off-road vehicle frame comprises a frame longitudinal beam, the frame longitudinal beam comprises a longitudinal beam front section, a longitudinal beam middle section and a longitudinal beam rear section which are sequentially arranged from front to back, and the longitudinal beam front section and the longitudinal beam rear section are located at the two ends of the longitudinal beam middle section correspondingly and detachably connected with each other; the longitudinal beam middle section comprises a middle section pipe body with the hollow interior and the two closed ends, a longitudinal partition plate is arranged in the middle section pipe body, and the longitudinal partition plate divides an inner cavity of the middle section pipe body into a gas storage cavity and a pipeline arrangement cavity which are mutually closed. The frame longitudinal beam is of a three-section combined structure composed of the longitudinal beam front section, the longitudinal beam middle section and the longitudinal beam rear section which are sequentially arranged from front to back, the frame manufacturing technological process is simplified, and the universality of a production line on the same platform and between platforms is achieved. In addition, the frame longitudinal beam is of a three-section combined structure, so that later replacement and maintenance are facilitated, the use and maintenance cost of a user is reduced, the impact on the wire harness under the cross-country working condition can be effectively prevented, and the safety of the whole vehicle is improved.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of non-load-bearing frames, in particular to an off-road vehicle frame based on multifunctional fusion and variable rigidity topology and a vehicle. BACKGROUND

[0002] The use of off-road vehicles is very harsh, and the chassis of the vehicle will be subjected to a large impact load when driving, which requires the off-road vehicle to have high off-road performance and high reliability. In order to meet the requirements of off-road performance and reliability of the vehicle, the off-road vehicle usually uses a non-load-bearing body, an independent suspension structure and a four-wheel drive system, and the lower part of the non-load-bearing body is a frame.

[0003] The frame of the vehicle serves as the load-bearing skeleton of the entire vehicle and has three very important functions: first, as a mounting and fixing structure of the entire vehicle, including the mounting of the body suspension, the mounting of the engine suspension, the mounting of the transfer case suspension, the mounting of the suspension, the fixing of the intake and exhaust systems and the oil tank, and the mounting and fixing of off-road equipment such as electric winches and rear trailer hooks.

[0004] Second, as the main load-bearing structure, it bears the impact force transmitted by the chassis, the braking force and the steering force of the entire vehicle, and the strength and reliability of the frame also determine the size of the load-carrying capacity of the entire vehicle; third, the frame has an important influence on the NVH performance, maintainability and maneuverability of the entire vehicle. The design of the frame not only needs to be based on the above-mentioned functions, but also needs to consider the manufacturing cost.

[0005] However, the non-load-bearing frame of the hard off-road vehicle also has the following technical pain points:

[0006] Conflict between weight and strength: In order to ensure load-bearing and torsional stiffness, the traditional frame longitudinal beam usually adopts a design scheme combining punched and welded thick plates and reinforcing plates, which results in excessive weight, affecting the fuel economy and power performance of the vehicle, especially in the current development of new energy vehicle models, the weight has a particularly important influence on the energy consumption of the entire vehicle.

[0007] Stress concentration: At key stress points such as suspensions, engine suspensions and towing hooks, traditional welding or riveting methods are prone to stress concentration, which becomes the source of fatigue cracks.

[0008] Poor functional expandability: As a huge load-bearing structure, the huge internal space of the frame is not effectively utilized. Accessories such as gas tanks, wire harnesses and air pipes are usually externally mounted, increasing the difficulty of arrangement and damage risk, and making it difficult to meet the production and manufacturing of different wheelbases, different front and rear suspensions, and even cross-platforms.

[0009] Complex manufacturing process: The complex local reinforcement structure requires multiple stamping and welding processes, and the production efficiency and consistency are challenged. SUMMARY

[0010] This application provides an off-road vehicle frame and vehicle based on multi-functional fusion and variable stiffness topology to solve the problems in related technologies where accessories such as air tanks, wiring harnesses, and air pipes of non-load-bearing frames are usually externally mounted, which increases the difficulty of layout and the risk of damage, as well as the difficulty in meeting the production and manufacturing requirements of different wheelbases, different front and rear overhangs, and even cross-platforms for platform models.

[0011] The first aspect of this application provides an off-road vehicle frame based on multifunctional fusion and variable stiffness topology, including: The frame longitudinal beam includes a front section, a middle section, and a rear section arranged sequentially from front to back. The front section and the rear section are located at both ends of the middle section and are detachably connected to each other. The longitudinal beam section includes a hollow, closed-end tube. The tube contains a longitudinal partition that divides the internal cavity of the tube into a sealed gas storage cavity and a pipeline arrangement cavity.

[0012] In some embodiments: the two ends of the middle section of the longitudinal beam are respectively connected to an inflation port and an exhaust port, and the inflation port and the exhaust port are both connected to the air storage cavity; The two ends of the middle section of the longitudinal beam are respectively connected to pipeline insertion interfaces, and pipelines connected to the pipeline insertion interfaces are arranged in the pipeline arrangement cavity.

[0013] In some embodiments: the middle section pipe and the longitudinal baffle are integrally extruded from aluminum alloy, and the gas storage cavity is located above the pipeline arrangement cavity; Bolted sleeves are connected through the side walls at both ends of the middle section of the pipe, and the bolted sleeves are sealed to the middle section of the pipe. The front and rear sections of the longitudinal beam are fitted onto the middle section of the tube body and are fastened to each other with bolts.

[0014] In some embodiments: a plurality of battery pack mounting holes for connecting power battery packs are provided on the middle section of the pipe body. The battery pack mounting holes are provided in a plurality of manner and are arranged at intervals along the length direction of the middle section of the pipe body. The plurality of battery pack mounting holes are interconnected with the pipeline arrangement cavity.

[0015] In some embodiments, the front section of the longitudinal beam includes a front straight section, a front inclined transition section, and a front overlapping section that are integrally thermo-expanded from front to back; The forward inclined transition section extends downward from the forward straight section to the forward overlapping section, and the forward overlapping section is sleeved on the middle section pipe and fastened to each other by bolts. The thickness and cross-section of the front straight section are both smaller than the thickness and cross-section of the front inclined transition section, while the cross-section of the front overlapping section is larger than the cross-section of the front inclined transition section.

[0016] In some embodiments: the front section of the longitudinal beam is welded to a powertrain mounting bracket, a body mounting bracket, and a front suspension mounting bracket, and the outer surface of the front tilt transition section is covered with a front carbon fiber reinforcement layer.

[0017] In some embodiments: the rear section of the longitudinal beam includes a rear overlap section, a rear inclined transition section, and a rear curved section, all integrally formed by hot air expansion from front to back; The rear inclined transition section extends obliquely upward from the rear overlapping section to the rear curved section, and the rear overlapping section is sleeved on the middle section pipe body and fastened to each other by bolts; The thickness and cross-section of the rear bending section are both smaller than those of the rear inclined transition section, while the cross-section of the rear overlapping section is larger than that of the rear inclined transition section.

[0018] In some embodiments: the rear section of the longitudinal beam is welded to a vehicle body suspension bracket and a rear suspension mounting bracket, and the outer surface of the rear tilt transition section is covered with a rear carbon fiber reinforcement layer.

[0019] In some embodiments: the frame longitudinal beams are provided in two sets, the two sets of frame longitudinal beams being a left frame longitudinal beam and a right frame longitudinal beam that are symmetrically spaced apart from each other; Multiple frame crossbeams are connected between the left frame longitudinal beam and the right frame longitudinal beam, and the multiple frame crossbeams are arranged at intervals along the length direction of the left frame longitudinal beam and the right frame longitudinal beam; Each of the multiple frame crossbeams has a crossbeam bracket detachably connected to both ends, and the crossbeam bracket is fixedly connected to the left frame longitudinal beam or the right frame longitudinal beam.

[0020] The second aspect of this application provides a vehicle including the off-road vehicle frame based on multi-functional fusion and variable stiffness topology as described in the previous embodiment; And the power battery pack located between the middle section of the longitudinal beam of the left frame and the middle section of the longitudinal beam of the right frame; The middle section of the longitudinal beam of the left frame and / or the middle section of the longitudinal beam of the right frame form the side frame of the power battery pack. The crossbeams located at both ends of the middle sections of the left and right longitudinal beams of the vehicle frame serve as the end frames of the power battery pack.

[0021] The beneficial effects of the technical solution provided in this application include: The embodiment of the present application provides an off-road vehicle frame and a vehicle based on multi-functional integration and variable stiffness topology. Since the off-road vehicle frame based on multi-functional integration and variable stiffness topology of the present application is provided with a frame longitudinal beam, the frame longitudinal beam includes a front longitudinal beam segment, a middle longitudinal beam segment, and a rear longitudinal beam segment arranged in sequence from front to back. The front longitudinal beam segment and the rear longitudinal beam segment are respectively located at both ends of the middle longitudinal beam segment and are detachably connected to each other; the middle longitudinal beam segment includes a middle pipe body with a hollow interior and closed ends. A longitudinal partition is provided in the middle pipe body, and the longitudinal partition divides the internal cavity of the middle pipe body into an air storage cavity and a pipeline layout cavity that are hermetically separated from each other.

[0022] Therefore, the off-road vehicle frame based on multi-functional integration and variable stiffness topology of the present application divides the frame longitudinal beam into a three-section combined structure of a front longitudinal beam segment, a middle longitudinal beam segment, and a rear longitudinal beam segment arranged in sequence from front to back, and the front longitudinal beam segment and the rear longitudinal beam segment are respectively located at both ends of the middle longitudinal beam segment and are detachably connected to each other. Furthermore, the production line flexibility of the off-road vehicle frame is better, which can meet the production and manufacturing of different wheelbases, different front and rear suspensions, and even cross-platform models under the platform model. There is no need to adjust and adapt the welding production line due to the size change of the off-road vehicle frame, which simplifies the frame manufacturing process flow and realizes the universality between the same platform and cross-platform of the production line. In addition, using a three-section combined structure for the frame longitudinal beam is convenient for later replacement and maintenance, reducing the user's use and maintenance costs.

[0023] In addition, the middle pipe body of the off-road vehicle frame based on multi-functional integration and variable stiffness topology of the present application has a hollow interior and closed ends, and a longitudinal partition is provided in the middle pipe body. The longitudinal partition divides the internal cavity of the middle pipe body into an air storage cavity and a pipeline layout cavity that are hermetically separated from each other. The middle pipe body and the longitudinal partition together form a cross-section in the shape of a "day". The middle longitudinal beam segment of this structure not only strengthens the mechanical properties of the frame longitudinal beam, but also serves as an air storage tank for the air spring and the side frame of the power battery pack. The pipeline layout cavity is used for预埋 the vehicle wiring harness, which can effectively protect the impact on the wiring harness under off-road conditions and improve the vehicle safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0025] Figure 1 It is the main view of the structure of the frame longitudinal beam in the embodiment of the present application; Figure 2 is Figure 1 the cross-sectional view along the B-B direction in Figure 3 It is the structural schematic diagram of the middle longitudinal beam segment in the embodiment of the present application; Figure 4 for Figure 3 A cross-sectional view along the AA direction; Figure 5 This is a top view of the structure of the off-road vehicle frame and power battery pack according to an embodiment of this application; Figure 6 This is a front view of the structure of the off-road vehicle frame and power battery pack according to an embodiment of this application.

[0026] Figure label: 10. Front section of longitudinal beam; 11. Front straight section; 12. Front inclined transition section; 13. Front overlapping section; 14. Powertrain mount bracket; 15. Front suspension mounting bracket; 16. Body mount bracket; 17. Front carbon fiber reinforcement layer; 18. Bolts; 20. Mid-section of longitudinal beam; 21. Mid-section pipe body; 22. Longitudinal partition; 23. Gas storage cavity; 24. Pipeline layout cavity; 25. Inflation interface; 26. Pipeline insertion interface; 27. Pipeline; 28. Bolt insertion sleeve; 29. ​​Battery pack mounting hole; 30. Rear section of longitudinal beam; 31. Rear overlap section; 32. Rear tilt transition section; 33. Rear bending section; 34. Rear suspension mounting bracket; 35. Rear carbon fiber reinforcement layer; 40. Left frame longitudinal beam; 50. Right frame longitudinal beam; 60. Frame crossbeam; 70. Crossbeam bracket; 100. Frame longitudinal beam; 200. Power battery pack. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0028] This application provides an off-road vehicle frame and vehicle based on multi-functional fusion and variable stiffness topology, which can solve the problems in related technologies where accessories such as air tanks, wiring harnesses, and air pipes of non-load-bearing frames are usually externally mounted, which increases the difficulty of layout and the risk of damage, as well as the difficulty in meeting the production and manufacturing requirements of different wheelbases, different front and rear overhangs, and even cross-platforms for platform models.

[0029] See Figures 1 to 4 As shown, the first aspect of this application provides an off-road vehicle frame based on multifunctional fusion and variable stiffness topology, the off-road vehicle frame comprising: Frame longitudinal beam 100, which includes a front longitudinal beam section 10, a middle longitudinal beam section 20, and a rear longitudinal beam section 30 arranged in sequence from front to back. The front longitudinal beam section 10 and the rear longitudinal beam section 30 are respectively located at both ends of the middle longitudinal beam section 20, and their overlapping parts are detachably connected.

[0030] Among them, the middle longitudinal beam section 20 includes a middle section tube body 21 with a hollow interior and closed ends. Inside the middle section tube body 21, there is a longitudinal partition 22, and the length direction of the longitudinal partition 22 is parallel to the length direction of the middle section tube body 21. The longitudinal partition 22 divides the internal cavity of the middle section tube body 21 into an air storage cavity 23 and a pipeline arrangement cavity 24 that are airtight to each other.

[0031] In the embodiment of the present application, the off-road vehicle frame based on multi-functional integration and variable stiffness topology divides the frame longitudinal beam 100 into a three-section combined structure of a front longitudinal beam section 10, a middle longitudinal beam section 20, and a rear longitudinal beam section 30 arranged in sequence from front to back. The front longitudinal beam section 10 and the rear longitudinal beam section 30 are respectively located at both ends of the middle longitudinal beam section 20 and are detachably connected to each other.

[0032] Furthermore, the production line of the off-road vehicle frame has better flexibility, can meet the production and manufacturing of different wheelbases, different front and rear suspensions, and even cross-platform models under the platform model. There is no need to adjust and adapt the welding production line due to the size change of the off-road vehicle frame, which simplifies the frame manufacturing process flow and realizes the universality between the same platform and cross-platform of the production line. In addition, using the three-section combined structure for the frame longitudinal beam 100 is convenient for later replacement and maintenance, reducing the user's use and maintenance costs.

[0033] In addition, the middle section tube body 21 of the off-road vehicle frame based on multi-functional integration and variable stiffness topology in the embodiment of the present application has a hollow interior and closed ends, and there is a longitudinal partition 22 inside the middle section tube body 21. The longitudinal partition 22 divides the internal cavity of the middle section tube body 21 into an air storage cavity 23 and a pipeline arrangement cavity 24 that are airtight to each other.

[0034] The middle section tube body 21 and the longitudinal partition 22 together form a cross-section in the shape of a Chinese character 'Ri'. The middle longitudinal beam section 20 of this structure not only strengthens the mechanical properties of the frame longitudinal beam 100, but also serves as an air storage tank for air springs and the side frame of the power battery pack 200. The pipeline arrangement cavity 24 is used for预埋整车线束和管路, which can effectively protect the impact on the wiring harness and pipeline under off-road conditions and improve the safety of the whole vehicle.

[0035] In some optional embodiments: Refer to Figure 3 and Figure 4 It should be noted that the part '预埋整车线束和管路' in the original text seems to be incomplete or incorrect Chinese expression. It is recommended to check and correct it to ensure the accuracy of the translation. Here it is tentatively translated as 'pre-buried vehicle wiring harness and pipelines'.As shown in the figure, an embodiment of the present application provides an off-road vehicle frame based on multi-functional integration and variable stiffness topology. Inflation interfaces 25 and exhaust interfaces are respectively connected to both ends of the middle section 20 of the longitudinal beam of the off-road vehicle frame. The inflation interfaces and the exhaust interfaces are both interconnected with the air storage cavity 23. The inflation interface 25 is connected with an inflation valve, and the exhaust interface is connected with an exhaust valve. Thus, the air storage cavity 23 of the middle section 20 of the longitudinal beam serves as an air storage tank for providing air source for the air suspension. The independent air storage tank is omitted, the chassis layout is optimized, and the cost and weight are reduced.

[0036] Pipeline socket interfaces 26 are respectively connected to both ends of the middle section 20 of the longitudinal beam. Pipelines 27 connecting the pipeline socket interfaces 26 are arranged in the pipeline layout cavity 24. The pipeline 27 includes any one or more of cables, air pipes, and oil pipes. The pipeline 27 is pre-installed in the pipeline layout cavity 24 of the middle section 20 of the longitudinal beam, and both ends are respectively connected to the pipeline socket interfaces 26. Thus, the pipeline 27 located inside the middle section 20 of the longitudinal beam and the pipeline 27 located outside the middle section 20 of the longitudinal beam are interconnected through the pipeline socket interfaces 26, which is convenient for repairing and replacing the middle section 20 of the longitudinal beam.

[0037] In some alternative embodiments: Refer to Figure 3 and Figure 4 As shown in the figure, an embodiment of the present application provides an off-road vehicle frame based on multi-functional integration and variable stiffness topology. The middle section pipe body 21 and the longitudinal partition plate 22 of the off-road vehicle frame are integrally extruded and formed from aluminum alloy. Both ends of the middle section pipe body 21 are welded and sealed by aluminum alloy end plates. The air storage cavity 23 is located above the pipeline layout cavity 24.

[0038] A plurality of bolt penetration sleeves 28 are respectively penetrated and connected to the side walls at both ends of the middle section pipe body 21. The plurality of bolt penetration sleeves 28 are hermetically connected to the middle section pipe body 21. Thus, after the plurality of bolt penetration sleeves 28 penetrate into the air storage cavity 23, the air storage cavity 23 remains in a closed state, avoiding the risk of air leakage. One end of the front section 10 of the longitudinal beam and the rear section 30 of the longitudinal beam close to the middle section 20 of the longitudinal beam are sleeved on the middle section pipe body 21 and are fastened and connected to each other by bolts 18.

[0039] The middle section 20 of the longitudinal beam in the embodiment of the present application abandons the "mouth" - shaped cross-section of the traditional vehicle frame longitudinal beam. In the present application, the middle section 20 of the longitudinal beam is formed by an aluminum alloy extrusion process, and the "day" - shaped cross-section is combined to form the structure of the middle section 20 of the longitudinal beam. The middle section 20 of the longitudinal beam with a "day" - shaped cross-section greatly improves the bending and torsional resistance performance of the whole vehicle. Under the same performance requirements, the thickness of the sheet material can be greatly reduced.

[0040] The frame longitudinal beam 100 adopts a three-section structure (front section 10, middle section 20 and rear section 30 of the longitudinal beam), and they are connected to each other by bolts 18. The production line is more flexible and can meet the production and manufacturing needs of different wheelbases, different front and rear suspensions, and even cross-platforms under the platform vehicle; there is no need to adjust the welding production line due to size changes.

[0041] In some alternative embodiments: see Figures 3 to 6 As shown, this application embodiment provides an off-road vehicle frame based on multifunctional fusion and variable stiffness topology. The middle section tube 21 of this off-road vehicle frame has multiple battery pack mounting holes 29 for connecting to a power battery pack 200. The battery pack mounting holes 29 are provided in multiples and are spaced apart sequentially along the length of the middle section tube 21. The multiple battery pack mounting holes 29 are interconnected with the pipeline arrangement cavity 24.

[0042] In this embodiment, the mid-section tube 21 is integrated with the power battery pack 200, eliminating the need for side frames in the power battery pack 200. The base plate of the power battery pack 200 can be connected to the mid-section tube 21 through multiple battery pack mounting holes 29, further reducing the weight and cost of the power battery pack 200. Due to the integration of the power battery pack 200 with the vehicle frame longitudinal beam 100, it can withstand higher-intensity impacts and torsion compared to the original side frames of the power battery pack 200, effectively improving the safety performance of the power battery pack 200.

[0043] In some alternative embodiments: see Figures 1 to 6 As shown, this application embodiment provides an off-road vehicle frame based on a multi-functional fusion and variable stiffness topology. The front section 10 of the longitudinal beam of the off-road vehicle frame includes a front straight section 11 integrally thermoformed from front to rear, a front inclined transition section 12, and a front overlapping section 13. The front inclined transition section 12 extends obliquely downward from the front straight section 11 to the front overlapping section 13. The front overlapping section 13 is sleeved on the middle section tube 21 and fastened to each other by bolts 18.

[0044] The thickness and cross-section of the front straight section 11 are both smaller than those of the front inclined transition section 12, while the cross-section of the front overlapping section 13 is larger than that of the front inclined transition section 12.

[0045] The front section 10 of the longitudinal beam adopts an integrated hot-air expansion molding process, combined with materials of unequal thickness, to achieve different cross sections and different material thicknesses in different performance areas, eliminating performance redundancy and achieving a lightweight design for the entire vehicle. At the same time, the integrated hot-air expansion molding process can avoid the thermal deformation of parts caused by large-area welding of the frame longitudinal beam 100, effectively ensuring the precision and production consistency of parts, while also ensuring the reliability and durability of the entire vehicle under off-road conditions.

[0046] In this embodiment, the front section 10 of the longitudinal beam is not of uniform cross-section. Instead, based on the overall vehicle load distribution (finite element analysis results), a combination of integrated hot-air expansion molding and variable cross-section and material thickness is used in high-stress areas. At points with higher stress, such as suspension mounting points, engine mount points, and body mounting points, a larger cross-section is used, and the material thickness is appropriately increased. At points with lower stress, the cross-section and material thickness are appropriately reduced. The material is distributed along the force flow path, avoiding material waste and achieving optimal material utilization.

[0047] The longitudinal beam front section 10 of this application embodiment achieves a weight reduction of about 20% in the frame assembly through variable cross-section, variable material thickness design and functional integration. The integrated hot air expansion molding process and the better force flow transmission path can improve the fatigue life of key points by more than 50%, achieve higher rigidity, and improve the vehicle's handling stability and body torsional resistance during off-road driving.

[0048] In some alternative embodiments: see Figures 1 to 6 As shown, this application embodiment provides an off-road vehicle frame based on multi-functional fusion and variable stiffness topology. The front section 10 of the longitudinal beam of the off-road vehicle frame is welded with a powertrain suspension bracket 14, a body suspension bracket 16 and a front suspension mounting bracket 15. The outer surface of the front tilt transition section 12 is covered with a front carbon fiber reinforcement layer 17. The front tilt transition section 12 is covered with the front carbon fiber reinforcement layer 17 to achieve the ultimate lightweighting of the whole vehicle.

[0049] In some alternative embodiments: see Figures 1 to 6 As shown, this application embodiment provides an off-road vehicle frame based on a multi-functional fusion and variable stiffness topology. The rear section 30 of the longitudinal beam of the off-road vehicle frame includes a rear overlapping section 31, a rear tilting transition section 32, and a rear bending section 33, which are integrally thermoformed from front to rear. The rear tilting transition section 32 extends obliquely upward from the rear overlapping section 31 to the rear bending section 33. The rear overlapping section 31 is sleeved on the middle section tube 21 and fastened to each other by bolts 18.

[0050] The thickness and cross-section of the rear bending section 33 are both smaller than those of the rear inclined transition section 32, while the cross-section of the rear overlapping section 31 is larger than that of the rear inclined transition section 32.

[0051] The rear section 30 of the longitudinal beam adopts an integrated hot-air expansion molding process, combined with materials of unequal thickness, to achieve different cross-sections and different material thicknesses in different performance areas, eliminating performance redundancy and achieving a lightweight design for the entire vehicle. At the same time, the integrated hot-air expansion molding process can avoid the thermal deformation of parts caused by large-area welding of the frame longitudinal beam 100, effectively ensuring the precision and production consistency of parts, while also ensuring the reliability and durability of the entire vehicle under off-road conditions.

[0052] In this embodiment, the rear section 30 of the longitudinal beam is not of uniform cross-section. Instead, based on the overall vehicle load distribution (finite element analysis results), a combination of integrated hot-air expansion molding and variable cross-section and material thickness is used in high-stress areas. At points with higher stress, such as suspension mounting points, engine mount points, and body mounting points, a larger cross-section is used, and the material thickness is appropriately increased. At points with lower stress, the cross-section and material thickness are appropriately reduced. The material is distributed along the force flow path, avoiding material waste and achieving optimal material utilization.

[0053] The rear section 30 of the longitudinal beam in this embodiment achieves a weight reduction of about 20% in the frame assembly through variable cross-section, variable material thickness design and functional integration. The integrated hot air expansion molding process and the better force flow transmission path can increase the fatigue life of key points by more than 50%, achieve higher rigidity, and improve the vehicle's handling stability and body torsional resistance during off-road driving.

[0054] In some alternative embodiments: see Figures 1 to 6 As shown, this application embodiment provides an off-road vehicle frame based on multi-functional fusion and variable stiffness topology. The rear section 32 of the longitudinal beam of the off-road vehicle frame is welded to the body suspension bracket 16 and the rear suspension mounting bracket 34. The outer surface of the rear tilt transition section 30 is covered with a rear carbon fiber reinforcement layer 35. The rear tilt transition section 30 is covered with the rear carbon fiber reinforcement layer 35 to achieve the ultimate lightweighting of the whole vehicle.

[0055] In some alternative embodiments: see Figure 5 and Figure 6 As shown in the figure, this application embodiment provides an off-road vehicle frame based on multifunctional fusion and variable stiffness topology. The off-road vehicle frame has two sets of frame longitudinal beams 100, namely a left frame longitudinal beam 40 and a right frame longitudinal beam 50 arranged symmetrically at intervals. Multiple frame crossbeams 60 are connected between the left frame longitudinal beam 40 and the right frame longitudinal beam 50, and the multiple frame crossbeams 60 are arranged at intervals along the length direction of the left frame longitudinal beam 40 and the right frame longitudinal beam 50.

[0056] Multiple frame crossbeams 60 have crossbeam supports 70 detachably connected to both ends. The crossbeam supports 70 are fixedly connected to the left frame longitudinal beam 40 or the right frame longitudinal beam 50. The crossbeam support 70 includes two parallel and spaced vertical plates, and an end plate connecting the two vertical plates. The two vertical plates and the end plate together form a "π" shape.

[0057] The end of the frame crossbeam 60 is clamped between two upright plates of the crossbeam bracket 70 and is detachably connected to each other by bolts 18, which facilitates the installation and removal of the frame crossbeam 60 and the crossbeam bracket 70, as well as the installation and removal of the power battery pack 200. The end plate of the crossbeam bracket 70 is connected to the inner wall of the left frame longitudinal beam 40 and the right frame longitudinal beam 50 by welding, riveting or bolts 18.

[0058] See Figure 5 and Figure 6 As shown, a second aspect of this application provides a vehicle, including the off-road vehicle frame based on multi-functional fusion and variable stiffness topology described in the previous embodiment; and a power battery pack 200 located between the middle section 20 of the longitudinal beam of the left frame 40 and the middle section 20 of the longitudinal beam of the right frame 50. The middle section 20 of the longitudinal beam of the left frame 40 and / or the middle section 20 of the longitudinal beam of the right frame 50 are the side frames of the power battery pack 200, and the frame crossbeams 60 located at both ends of the middle sections 20 of the longitudinal beams of the left frame 40 and the right frame 50 are the end frames of the power battery pack 200.

[0059] In this embodiment, the middle section 20 of the left frame longitudinal beam 40 and the middle section 20 of the right frame longitudinal beam 50 are integrated with the power battery pack 200, eliminating the side frame of the power battery pack 200 itself. The frame crossbeams 60 located at both ends of the middle section 20 of the left frame longitudinal beam 40 and the middle section 20 of the right frame longitudinal beam 50 serve as the end frames of the power battery pack 200. Eliminating the end frames of the power battery pack 200 itself can significantly reduce the weight and cost of the power battery pack 200. Since the power battery pack 200 is integrated on the frame longitudinal beam 100 and the frame crossbeam 60, it can withstand higher intensity impacts and torsions compared to the original side beams and end beams of the power battery pack 200, effectively improving the safety performance of the power battery pack 200.

[0060] Working principle This application provides an off-road vehicle frame and vehicle based on a multi-functional fusion and variable stiffness topology. The off-road vehicle frame based on the multi-functional fusion and variable stiffness topology of this application is provided with a frame longitudinal beam 100. The frame longitudinal beam 100 includes a front section 10, a middle section 20 and a rear section 30 arranged sequentially from front to back. The front section 10 and the rear section 30 are located at both ends of the middle section 20 and are detachably connected to each other. The middle section 20 includes a hollow middle tube 21 with closed ends. A longitudinal partition 22 is provided inside the middle tube 21. The longitudinal partition 22 divides the internal cavity of the middle tube 21 into a sealed air storage cavity 23 and a pipeline arrangement cavity 24.

[0061] Therefore, the off-road vehicle frame based on multi-functional integration and variable stiffness topology of the present application divides the frame longitudinal beam 100 into a three-section combined structure of a front longitudinal beam section 10, a middle longitudinal beam section 20, and a rear longitudinal beam section 30 arranged in sequence from front to back. The front longitudinal beam section 10 and the rear longitudinal beam section 30 are respectively located at both ends of the middle longitudinal beam section 20 and are detachably connected to each other. Furthermore, the production line flexibility of the off-road vehicle frame is better, which can meet the production and manufacturing of different wheelbases, different front and rear suspensions, and even cross-platform models under platform models, without the need to adjust and adapt the welding production line due to the size change of the off-road vehicle frame, simplifies the frame manufacturing process flow, and realizes the universality between the same platform and cross-platform of the production line. In addition, using a three-section combined structure for the frame longitudinal beam 100 is convenient for later replacement and maintenance, and reduces the user's use and maintenance costs.

[0062] In addition, the middle section pipe body 21 of the off-road vehicle frame based on multi-functional integration and variable stiffness topology of the present application is a structure with a hollow interior and closed ends, and a longitudinal partition 22 is provided inside the middle section pipe body 21. The longitudinal partition 22 divides the internal cavity of the middle section pipe body 21 into an air storage cavity 23 and a pipeline layout cavity 24 that are hermetically sealed from each other. The middle section pipe body 21 and the longitudinal partition 22 together form a cross-section in the shape of a Chinese character 'Ri'. The middle longitudinal beam section 20 of this structure not only strengthens the mechanical properties of the frame longitudinal beam 100, but also serves as an air storage tank for air springs and the side frame of the power battery pack 200. The pipeline layout cavity 24 is used for pre-burying the vehicle harness, which can effectively protect the impact on the harness under off-road conditions and improve the safety of the whole vehicle.

[0063] In the description of the present application, it should be noted that the orientation or positional relationship indicated by terms such as 'upper' and 'lower' is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, so it cannot be understood as a limitation to the present application. Unless otherwise clearly specified and defined, the terms 'installed', 'connected', and 'coupled' should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the internal connection of two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0064] It should be noted that in this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0065] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A cross-country vehicle frame based on multifunctional fusion and variable stiffness topology, characterized in that, include: The frame longitudinal beam (100) includes a front section (10), a middle section (20) and a rear section (30) of the longitudinal beam arranged from front to back. The front section (10) and the rear section (30) of the longitudinal beam are located at the two ends of the middle section (20) of the longitudinal beam and are detachably connected to each other. The longitudinal beam middle section (20) includes a hollow middle section tube (21) that is closed at both ends. The middle section tube (21) is provided with a longitudinal partition (22). The longitudinal partition (22) divides the internal cavity of the middle section tube (21) into a mutually sealed gas storage cavity (23) and a pipeline arrangement cavity (24).

2. The off-road vehicle frame based on multi-functional fusion and variable stiffness topology as described in claim 1, characterized in that: The two ends of the middle section (20) of the longitudinal beam are respectively connected to an inflation port (25) and an exhaust port, and the inflation port (25) and the exhaust port are both connected to the air storage cavity (23). The two ends of the middle section (20) of the longitudinal beam are respectively connected to the pipeline insertion interface (26), and the pipeline (27) connected to the pipeline insertion interface (26) is arranged in the pipeline arrangement cavity (24).

3. A cross-country vehicle frame based on multifunctional fusion and variable stiffness topology as described in claim 1 or 2, characterized in that: The middle section pipe (21) and the longitudinal partition (22) are integrally extruded aluminum alloys, and the gas storage cavity (23) is located above the pipeline arrangement cavity (24); Bolt-inserted sleeves (28) are connected through the side walls at both ends of the middle section pipe (21), and the bolt-inserted sleeves (28) are sealed to the middle section pipe (21). The front section (10) and the rear section (30) of the longitudinal beam are fitted onto the middle section (20) of the longitudinal beam at one end and are fastened to each other by bolts (18).

4. The off-road vehicle frame based on multifunctional fusion and variable stiffness topology as described in claim 3, characterized in that: The middle section pipe (21) has multiple battery pack mounting holes (29) for connecting the power battery pack (200). The battery pack mounting holes (29) are provided in multiple ways and are arranged at intervals along the length of the middle section pipe (21). The multiple battery pack mounting holes (29) are interconnected with the pipeline arrangement cavity (24).

5. The off-road vehicle frame based on multifunctional fusion and variable stiffness topology as described in claim 1, characterized in that: The front section (10) of the longitudinal beam includes a front straight section (11), a front inclined transition section (12), and a front overlapping section (13) formed by hot air expansion from front to back. The forward inclined transition section (12) extends downward from the forward straight section (11) to the forward overlapping section (13), and the forward overlapping section (13) is sleeved on the middle section pipe (21) and fastened to each other by bolts (18). The thickness and cross-section of the front straight section (11) are both smaller than the thickness and cross-section of the front inclined transition section (12), and the cross-section of the front overlapping section (13) is larger than the cross-section of the front inclined transition section (12).

6. The off-road vehicle frame based on multifunctional fusion and variable stiffness topology as described in claim 5, characterized in that: The front section (10) of the longitudinal beam is welded to a powertrain suspension bracket (14), a body suspension bracket (16) and a front suspension mounting bracket (15), and the outer surface of the front tilt transition section (12) is covered with a front carbon fiber reinforcement layer (17).

7. The off-road vehicle frame based on multifunctional fusion and variable stiffness topology as described in claim 1, characterized in that: The rear section (30) of the longitudinal beam includes a rear overlapping section (31), a rear inclined transition section (32), and a rear bending section (33) formed by hot air expansion from front to back. The rear inclined transition section (32) extends obliquely upward from the rear overlapping section (31) to the rear curved section (33). The rear overlapping section (31) is sleeved on the middle section pipe (21) and fastened to each other by bolts (18). The thickness and cross-section of the rear bending section (33) are both smaller than the thickness and cross-section of the rear inclined transition section (32), and the cross-section of the rear overlapping section (31) is larger than the cross-section of the rear inclined transition section (32).

8. The off-road vehicle frame based on multifunctional fusion and variable stiffness topology as described in claim 7, characterized in that: The rear section (30) of the longitudinal beam is welded to a body suspension bracket (16) and a rear suspension mounting bracket (34), and the outer surface of the rear tilt transition section (32) is covered with a rear carbon fiber reinforcement layer (35).

9. The off-road vehicle frame based on multifunctional fusion and variable stiffness topology as described in claim 1, characterized in that: The frame longitudinal beams (100) are provided in two sets, and the two sets of frame longitudinal beams (100) are left frame longitudinal beams (40) and right frame longitudinal beams (50) that are symmetrically spaced apart from each other. Multiple frame crossbeams (60) are connected between the left frame longitudinal beam (40) and the right frame longitudinal beam (500), and the multiple frame crossbeams (60) are arranged at intervals along the length direction of the left frame longitudinal beam (40) and the right frame longitudinal beam (50); The two ends of the multiple frame crossbeams (60) are respectively detachably connected to crossbeam brackets (70), and the crossbeam brackets (70) are fixedly connected to the left frame longitudinal beam (40) or the right frame longitudinal beam (50).

10. A vehicle, characterized in that, Including the off-road vehicle frame based on multifunctional fusion and variable stiffness topology as described in claim 9; And the power battery pack (200) located between the middle section (20) of the longitudinal beam of the left frame (40) and the middle section (20) of the longitudinal beam of the right frame (50). The middle section (20) of the longitudinal beam of the left frame (40) and / or the middle section (20) of the longitudinal beam of the right frame (50) are the side frame of the power battery pack (200). The frame crossbeams (60) located at both ends of the middle section (20) of the left frame longitudinal beam (40) and the middle section (20) of the right frame longitudinal beam (50) are the end frames of the power battery pack (200).

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