A vehicle frame-based bolted powertrain mount structure and vehicle

Abstract

This invention discloses a frame-based screw-connected powertrain suspension bracket structure, including a frame crossbeam. A left end plate, a right end plate, and a lower end plate are connected to the frame crossbeam. Both the left and right end plates have mounting bolt connection holes. The left and right end plates each have connecting flanges on their sides. The lower end plate has a connecting portion. One end of the connecting flange and one end of the connecting portion are respectively connected to the top and bottom of the frame, and the other end of the connecting flange is connected to the other end of the connecting portion. Using this frame-based screw-connected powertrain suspension bracket structure improves layout flexibility, optimizes the dynamic stiffness and vibration isolation performance of the mounting point, and enhances connection reliability.

Description

Technical Field

[0001] This invention belongs to the field of automotive powertrain mounting systems. Specifically, this invention relates to a screw-type powertrain mounting bracket structure based on a vehicle frame. Background Technology

[0002] Traditional fuel-powered pickup trucks generally use a structure in which steel suspension brackets are directly welded and fixed to the crossbeams of the chassis. Welding achieves a rigid connection between the brackets and the chassis, ensuring reliable load transfer.

[0003] With the development of electric vehicles converted from gasoline models, the requirements for the arrangement of front drive motor mounts have changed. Some models have begun to use screw-type mount brackets to achieve detachable maintenance. However, the existing screw-type mount brackets still use the traditional sheet metal splicing structure. The mounting surface of the mount bracket and the frame is in rigid contact with pure steel without a buffer structure. Moreover, the dynamic stiffness of the powertrain mounting point and the vibration isolation performance of the mount are only guaranteed by the thickness of the sheet metal, which is ineffective. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing technologies by providing a frame-based screw-type powertrain suspension bracket structure that improves layout flexibility, optimizes the dynamic stiffness and vibration isolation performance of the mounting point, and enhances connection reliability.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: The frame-based screw-in powertrain mounting bracket structure includes a frame crossbeam, on which a left end plate, a right end plate, and a lower end plate are connected. Both the left and right end plates are provided with mounting bolt connection holes. Both the left and right end plates have connecting flanges on their sides. The lower end plate has a connecting part. One end of the connecting flange and one end of the connecting part are respectively connected to the top and bottom of the frame, and the other end of the connecting flange is connected to the other end of the connecting part.

[0006] The frame crossbeam includes a first crossbeam plate and a second crossbeam plate. Both the first crossbeam plate and the second crossbeam plate have a U-shaped cross-section structure. The outer edge of the first crossbeam plate contacts the inner edge of the second crossbeam plate and is fixedly connected. The top of the connecting flange is connected to the top of the first crossbeam plate, and the connecting part is connected to the bottom of the second crossbeam plate. Bolt holes are provided at both ends of the connecting flange and both ends of the connecting part.

[0007] The left and right end plates are symmetrically arranged, the axis of the suspension mounting bolt connection hole is parallel to the length direction of the frame beam, and a friction-reducing ring is provided in the suspension mounting bolt connection hole.

[0008] Both ends of the connecting flange and both ends of the lower end plate are planar structures. A buffer pad installation gap is provided between the top of the connecting flange and the top of the first crossbeam plate. A buffer pad installation gap is provided between the connecting part and the second crossbeam plate. A buffer pad installation gap is provided between the connecting flange and the connecting part.

[0009] The top edge of the connecting flange abuts against the edge of the second crossbeam plate; both the top of the left end plate and the right end plate are provided with folded edges, and the folded edges of the left end plate and the right end plate are in contact and fixedly connected.

[0010] The lower end plate is provided with reinforcing ribs between the connecting parts, and both the connecting parts and the reinforcing ribs have arched cross-sections.

[0011] The connecting part and the reinforcing rib form a wire passage, and the lower end plate has a relief groove in the middle of one end.

[0012] The first and second crossbeams are provided with multiple weight-reducing holes, and the top of the first and second crossbeams are provided with multiple holes at equal intervals.

[0013] All bolt hole openings are vertical.

[0014] Vehicles, including the aforementioned frame-based screw-type powertrain suspension bracket structure.

[0015] The technical effects of this invention are as follows: The frame-based screw-connected powertrain mount structure solves the problems of inflexible layout and non-removable maintenance of traditional welded mounts, enabling fully screw-connected and detachable assembly of the mount and frame, thus improving layout flexibility and after-sales maintainability. It also solves the problems of frictional noise caused by rigid metal contact at the screw-connected mounting surface, uneven bolt preload, and poor connection reliability, achieving noise suppression and uniform preload distribution at the mounting surface. Furthermore, it addresses the problems of insufficient dynamic stiffness and poor vibration isolation performance at the mounting point, ensuring that the dynamic stiffness of the mounting point meets vibration isolation design requirements within the 20-200Hz core frequency band, thereby improving the overall vehicle NVH performance.

[0016] In summary, by establishing a fully threaded, detachable connection between the left, right, and lower end plates, combined with the elastic buffering and sealing effect of the friction-reducing ring, and the multi-directional load distribution effect of the spatial frame structure, this frame-based threaded powertrain mount structure addresses the challenges of traditional mounts in terms of layout flexibility, noise reduction, and vibration isolation. Since converted electric vehicles require a relocation of motor mounting points within limited chassis space, higher demands are placed on the adaptability, adjustability, and NVH performance of the mount. Suitable for the development needs of converted electric vehicles, this frame-based threaded powertrain mount structure solves the problems of traditional mounts in terms of layout flexibility, noise reduction, and vibration isolation. It achieves these functions through relatively simple sheet metal assembly, without relying on complex casting or forging processes, and has good cost controllability and mass production feasibility. This provides a practical mount solution for the electrification transformation of commercial vehicles such as pickup trucks. Attached Figure Description

[0017] This manual includes the following figures, which illustrate the following: Figure 1 This is a schematic diagram of the frame-based screw-type powertrain suspension bracket structure of the present invention; Figure 2 This is a side view of the frame-based screw-type powertrain suspension bracket structure of the present invention; Figure 3 This is a schematic diagram showing the connection between the left end plate, the right end plate, and the top of the frame crossbeam of the present invention; Figure 4 This is a schematic diagram showing the connection between the left end plate, the right end plate, and the bottom of the frame crossbeam of the present invention; Figure 5 This is a schematic diagram of the structure of the left end plate, right end plate and lower end plate of the present invention; Figure 6 This is a schematic diagram of the structure of the lower end plate of the present invention.

[0018] The markings in the diagram are as follows: 1. Frame crossbeam; 2. Left end plate; 3. Right end plate; 4. Lower end plate; 5. First crossbeam plate; 6. Second crossbeam plate; 7. Suspension mounting bolt connection hole; 8. Connecting flange; 9. Folded edge; 10. Bolt hole; 11. Connecting part; 12. Anti-friction ring; 13. Buffer pad installation gap; 14. Reinforcing rib; 15. Cable passage; 16. Clearance groove; 17. Weight reduction hole; 18. Hole position. Detailed Implementation

[0019] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings, in order to help those skilled in the art to have a more complete, accurate and in-depth understanding of the inventive concept and technical solution of the present invention, and to facilitate its implementation.

[0020] like Figure 1 As shown, the frame-based screw-type power suspension bracket structure includes a frame crossbeam 1, on which a left end plate 2, a right end plate 3, and a lower end plate 4 are connected. Both the left end plate 2 and the right end plate 3 are provided with suspension mounting bolt connection holes 7. Both the left end plate 2 and the right end plate 3 are provided with connecting flanges 8 on their sides. The lower end plate 4 is provided with a connecting part 11. One end of the connecting flange 8 and one end of the connecting part 11 are respectively connected to the top and bottom of the frame, and the other end of the connecting flange 8 is connected to the other end of the connecting part 11.

[0021] The aforementioned structure forms a spatial frame-type suspension bracket. The left end plate 2 and right end plate 3 serve as lateral load-bearing components, while the lower end plate 4 serves as the bottom connecting component. Together, these three components enclose a semi-enclosed load-bearing cavity. Compared to traditional suspension brackets, this spatial frame structure has a higher bending section modulus and torsional stiffness, enabling it to transfer the vertical, longitudinal, and lateral loads generated by the powertrain to different parts of the frame: vertical loads are transferred to the bottom of the frame through the connecting part 11 of the lower end plate 4, while lateral and longitudinal loads are transferred to the top of the frame and the lower end plate 4 through the connecting flanges 8 of the left and right end plates 3. This design effectively avoids stress concentration at a single connection point, thus improving the fatigue life of the bracket.

[0022] This suspension structure is used to support the front drive motor suspension bushing, which diverts and attenuates the static self-weight load and dynamic vibration load of the motor, and finally safely transmits them to the frame crossbeam 1. While ensuring reliable load transmission, it blocks vibration and noise from being transmitted to the cab to the greatest extent. At the same time, it can be fully bolted and detached, improving layout flexibility and after-sales maintainability. Its main body consists of three parts: left end plate 2, right end plate 3, and lower end plate 4. All plates are made of 4mm thick Q345B low alloy high strength steel through stamping, bending and laser welding processes.

[0023] like Figure 5 As shown, the left end plate 2 and right end plate 3 are laser-welded to form the main load-bearing frame. The left end plate 2, right end plate 3, and lower end plate 4 are fastened together with M10 high-strength bolts. The entire bracket is bolted to the frame crossbeam 1 through φ10mm mounting holes. The suspension bushing and front drive motor are bolted to the bracket, forming a fully bolted, detachable structure. This solves the problems of inflexible suspension bracket layout, excessive noise, poor welding precision, and insufficient dynamic rigidity in existing suspension brackets. The aforementioned bolted, detachable structure design eliminates the permanent connection between the suspension bracket and the frame. When the vehicle undergoes powertrain upgrades or repairs, the entire bracket can be removed simply by loosening the bolts, without any cutting or re-welding of the frame, significantly reducing the technical threshold and labor costs for after-sales maintenance. Furthermore, the left end plate 2, right end plate 3, and lower end plate 4 are also bolted together. If any plate is deformed due to an accidental collision, only the damaged plate needs to be replaced, without scrapping the entire bracket assembly, saving on repair material costs. The application of laser welding technology ensures that the left and right end plates 3 form an integral load-bearing frame after welding. Its connection strength is sufficient to withstand the alternating load generated by the motor during operation, and the weld is flat and smooth, requiring no subsequent grinding treatment, which improves production efficiency and product consistency.

[0024] like Figure 1As shown, the frame crossbeam 1 includes a first crossbeam plate 5 and a second crossbeam plate 6. Both the first crossbeam plate 5 and the second crossbeam plate 6 have U-shaped cross-sections. The outer edge of the first crossbeam plate 5 contacts and is fixedly connected to the inner edge of the second crossbeam plate 6. The top of the connecting flange 8 is connected to the top of the first crossbeam plate 5, and the connecting part 11 is connected to the bottom of the second crossbeam plate 6. Bolt holes 10 are provided at both ends of the connecting flange 8 and the connecting part 11. The frame crossbeam 1 adopts a double-layer U-shaped cross-section interlocking structure. The edges of the two crossbeam plates overlap to form a closed box-shaped cross-section. This design creates a certain height difference between the top of the outer plate and the bottom of the inner plate, thus providing independent mounting planes for the connecting flange 8 and the connecting part 11. That is, the connecting flange 8 is fixed to the top of the outer plate, and the connecting part 11 is fixed to the bottom of the inner plate. The two are staggered in the vertical direction, so that the load transmitted by the bracket can be evenly distributed at the top and bottom of the crossbeam, avoiding local buckling of the crossbeam caused by load concentration. This staggered load transfer method ensures that when the frame crossbeam 1 is subjected to forces from the suspension brackets, its top and bottom are constrained in different directions. This creates a mutually canceling internal force distribution within the crossbeam, effectively suppressing torsional deformation of the crossbeam section. Compared to the traditional approach of concentrating all connection points on the same side of the crossbeam, this structure results in a more balanced stress state for the crossbeam, preventing weld cracking or permanent deformation caused by localized overload.

[0025] like Figure 5 As shown, the left end plate 2 and the right end plate 3 are symmetrically arranged. The axis of the suspension mounting bolt connection hole 7 is parallel to the length direction of the frame crossbeam 1. A friction-reducing ring 12 is provided inside the suspension mounting bolt connection hole 7. The friction-reducing ring 12 is installed inside the suspension mounting bolt connection hole 7, so that the suspension mounting bolt no longer directly contacts the metal hole wall when passing through the suspension mounting bolt connection hole 7. Instead, the force is transmitted and buffered through the friction-reducing ring 12. This structure eliminates the source of abnormal noise caused by fretting friction between metals, and also avoids the problem of hole wall wear and hole diameter enlargement caused by long-term vibration. The shallow groove of the friction-reducing ring 12 ensures that the friction-reducing ring 12 can be accurately positioned during the press-fitting process and will not be offset or fall off during subsequent assembly or use.

[0026] The friction-reducing ring 12 is molded from oil-resistant, temperature-resistant, and aging-resistant fluororubber. It features an ultra-thin ring structure with a thickness of 0.2mm, an inner diameter of φ10mm (matching the inner diameter of the mounting hole), and an outer diameter of φ13.2mm, forming a 0.05mm interference fit with the shallow mounting groove of the friction-reducing ring 12. This interference fit design has been verified through CAE simulation and testing, ensuring that the friction-reducing ring 12 achieves self-locking fixation through its own elasticity after press-fitting, eliminating the need for adhesives, welding, or mechanical clips for auxiliary fixation. This simplifies the assembly process and prevents the friction-reducing ring 12 from detaching due to adhesive failure under high-temperature conditions. The friction-reducing ring 12 has a smooth surface and a hardness between Shore A 65±5, balancing buffering performance and compression rebound performance. After the bolts are tightened, it generates a controllable compression of 0.05mm, which completely fills the microscopic gaps between the mounting surfaces, preventing direct metal-to-metal contact and eliminating friction noise. However, excessive compression will not reduce the positioning accuracy of the bracket or cause the mounting surface to tilt, ensuring that the dynamic stiffness of the mounting point remains unaffected. The anti-friction ring 12 has a temperature resistance range of -40℃ to +150℃, meeting the requirements of the entire vehicle under all operating conditions. It has excellent oil resistance and aging resistance, with a service life of ≥10 years, synchronized with the life of the entire vehicle. The anti-friction ring 12 can be replaced with elastic materials such as nitrile rubber, silicone rubber, and hydrogenated nitrile rubber, selected according to the temperature resistance, oil resistance, and aging resistance requirements of the vehicle's operating conditions. The size, interference fit, and mounting groove structure of the anti-friction ring 12 remain unchanged, still achieving the functions of suppressing abnormal noise, balancing preload, and sealing.

[0027] like Figure 5 and Figure 6 As shown, both ends of the connecting flange 8 and the lower end plate 4 are planar structures. A buffer pad installation gap 13 is provided between the top of the connecting flange 8 and the top of the first crossbeam plate 5, between the connecting part 11 and the second crossbeam plate 6, and between the connecting flange 8 and the connecting part 11. The reserved buffer pads in the three buffer pad installation gaps 13 create a sandwich structure with an elastic body between the suspension bracket and the vehicle frame. The buffer pads can absorb and disperse vertical vibrations and longitudinal impacts. Simultaneously, the reserved buffer pad installation gaps 13 give this bracket upward compatibility; that is, without changing the main sheet metal structure, buffer pads of different hardness and thickness can be selected to fill these gaps according to the vibration characteristics of different vehicle models to achieve customized vibration isolation effects. When no additional buffering is needed, these gaps can be directly supplemented by adjusting and pre-tightening the bolts, and the bracket and vehicle frame can still achieve a reliable connection without affecting load transmission. The cushioning pads in the sandwich structure also serve to adjust installation tolerances. When manufacturing errors in the frame or bracket cause tiny gaps between the connecting surfaces, the cushioning pads can be compressed to fill these gaps, ensuring that each connection point can make effective contact.

[0028] like Figure 3As shown, the top edge of the connecting flange 8 abuts against the edge of the second crossbeam plate 6; both the left end plate 2 and the right end plate 3 have folded edges 9 at their tops, and the folded edges 9 of the left end plate 2 and the right end plate 3 are in contact and fixedly connected. The abutment between the top edge of the connecting flange 8 and the edge of the second crossbeam plate 6 forms a limit, preventing the bracket from undergoing excessive rotational displacement relative to the frame. The folded edges 9 at the top of the left and right end plates 3 are in contact with each other and fixed by welding, which significantly improves the overall rigidity of the bracket, making the separate left and right end plates 3 connected as one at the top, jointly resisting the lateral thrust from the suspension bushing, and avoiding the outward deformation of the end plates caused by unilateral force.

[0029] like Figure 6 As shown, a reinforcing rib 14 is provided on the lower end plate 4 between the connecting parts 11. Both the connecting parts 11 and the reinforcing rib 14 have arched cross-sections. This structure can improve the torsional strength and fatigue resistance of the bent parts of the lower end plate 4, and prevent bending deformation under long-term load. The connecting parts 11 on the lower end plate 4 have arched cross-sections. When the frame pushes the connecting parts 11 upwards with bolts, the connecting parts 11 will not bend like a flat plate, but will transfer the force to both sides of the arch, which will then be borne by the main structure of the lower end plate 4. The two arched connecting parts 11 and one arched reinforcing rib 14 form a parallel structure on the lower end plate 4, so that even when the lower end plate 4 is subjected to uneven loads, the arches can support each other and jointly resist deformation, thereby improving the bending section modulus of the lower end plate 4.

[0030] like Figure 6 As shown, a wire passage 15 is formed between the connecting part 11 and the reinforcing rib 14, and a clearance groove 16 is provided in the middle of one end of the lower end plate 4. In traditional suspension brackets, motor wiring harnesses and cooling pipes often need to be routed around the outside of the bracket, occupying extra space and increasing the length of the wiring harness. The above structure utilizes the natural gap between the connecting part 11 and the reinforcing rib 14 to create a wire passage 15 on the lower end plate 4, allowing the wiring harness to pass through the inside of the bracket, protecting the wiring harness from external impacts, shortening the routing distance, and because the position of the wire passage 15 is fixed, the pipeline has a clear direction guide during assembly, reducing the problem of pipeline twisting or bending caused by differences in worker operation, and improving the stability of assembly quality. The clearance groove 16 is located at one end of the bracket, freeing up installation space for the low-voltage connector of the front drive motor, preventing interference between the motor housing and the bracket, thereby reducing the need for additional wire clips and pipe clamps, making the overall front compartment layout of the vehicle neater and simplifying the assembly process.

[0031] like Figure 1As shown, both the first crossbeam plate 5 and the second crossbeam plate 6 are provided with multiple weight-reduction holes 17, and multiple holes 18 are equally spaced at the top of the first crossbeam plate 5 and the bottom of the second crossbeam plate 6. The weight-reduction holes 17 are located in non-critical load-bearing areas of the frame crossbeam 1, and can reduce weight by approximately 8% to 12% without reducing the overall rigidity of the crossbeam. The equally spaced holes 18 allow the mounting position of the suspension bracket on the frame crossbeam 1 to be flexibly adjusted along the length direction. Each hole 18 corresponds to a different mounting position. When there are steering gears, exhaust pipes, or other obstacles near the frame crossbeam 1, the assembler can choose to bolt the bracket to the hole 18 that avoids the obstacle without making any modifications to the bracket or crossbeam. This makes it suitable for vehicles converted from gasoline to electric vehicles, as the size and layout of the motor are often different from the original engine, and the suspension bracket needs to be able to adapt to the new spatial constraints.

[0032] like Figure 1 As shown, all bolt holes 10 have vertical openings, allowing operators or robotic arms to work from above without needing to operate laterally or at an angle, significantly reducing assembly difficulty. This makes them suitable for automated tightening using a suspended tightening gun at the chassis assembly station. The vertical openings also facilitate the installation of anti-loosening marks on the bolt heads, allowing quality inspectors to quickly visually check whether the bolts have come loose, thus improving quality inspection efficiency.

[0033] The left end plate 2, right end plate 3, and lower end plate 4 are formed by stamping, bending, or welding processes and are detachably connected by high-strength bolts. The bracket is designed to fit the mounting profile of the pickup truck frame beam 1. The upper part is fixed to the frame beam 1, while the lower part connects to the front drive motor's suspension bushing and the lower end plate 4. Space is reserved in the middle for frame piping, satisfying the spatial layout requirements of the pickup truck chassis while achieving a balance between strength and lightweight through structural optimization. The left and right end plates 3 serve as the core load-bearing structure and the foundation for connecting to the frame, bearing the assembly of the suspension rubber bushing and the vibration load from the motor. The lower end plate 4 acts as the bottom link connecting the left and right end plates 3 and bears the lower load of the suspension. The three components work together to form a stable triangular support structure, effectively distributing the static weight load and dynamic vibration load generated by the front drive motor during operation.

[0034] The left end plate 2 has an outline that matches the left mounting surface of the frame crossbeam 1. It features a planar assembly surface for connecting to the frame, with a flatness error controlled within 0.05mm to ensure precise fit with the frame. It also has a vertical mating end face for welding to the right end plate 3, with a flatness error ≤0.03mm to ensure a tight fit during welding. Furthermore, it has a transverse flange structure for connecting to the lower end plate 4, with a flange width of 20mm. The flange end face is milled, with a flatness error ≤0.05mm to ensure precise fit with the lower end plate 4. The left end plate 2 has a total of four φ10mm mounting holes, two of which are for frame suspension bolts 7, and the other two are for the lower end plate 4 suspension bolts 7.

[0035] The right end plate 3 has a symmetrical design with the left end plate 2. It features mounting points for suspension bushings, a vertically welded butt joint surface that matches the left end plate 2, and a transverse flange that connects to the lower end plate 4. The flange dimensions and flatness requirements are consistent with those of the left end plate 2 to ensure assembly consistency. The right end plate 3 also has four φ10mm mounting holes, two of which are for frame suspension bolts 7, and two of which are for lower end plate 4 suspension bolts 7. The mounting groove dimensions and precision requirements of the anti-friction ring 12 on the mounting hole surface are consistent with those of the left end plate 2 to ensure parts commonality and assembly consistency.

[0036] A matching circular positioning recess (not shown in the figure) is machined on the end face of the folded edge 9 of the right end plate 3. The recess has a diameter of φ2mm and a depth of 0.3mm. The fit clearance between the recess and the boss is controlled between 0.02 and 0.05mm to ensure smooth assembly and positioning before welding, without causing positioning failure due to excessive clearance, thus achieving precise self-positioning before welding. A circular miniature positioning boss (not shown in the figure) is stamped in the middle of the end face of the folded edge 9 of the left end plate. The boss has a diameter of φ2mm and a height of 0.3mm. The root of the boss uses a radius of 0.5mm to avoid stress concentration and welding interference. This positioning boss plays a role in radial positioning and circumferential error prevention during the welding process, ensuring the accuracy of the docking position of the left and right end plates 3 and eliminating the problem of reverse assembly. The combination of the aforementioned recesses and bosses can solve the problems of lack of self-positioning, large welding deformation, and poor batch consistency in laser welding of the left and right end plates, and improve the assembly accuracy and batch product consistency of laser welding; without the need for complex tooling, the thermal deformation of laser welding is reduced from ±0.5mm to within ±0.1mm, the consistency of the mounting hole positions of batch products is improved by 80%, the problem of uneven load on the suspension bushing is solved, the life of the suspension system is increased by 50%, and the vibration isolation efficiency is stably up to standard. Example

[0037] The left end plate 2, right end plate 3, and lower end all use 4mm thick Q345B low-alloy high-strength steel plate as the base material. This material has a yield strength ≥345MPa and a tensile strength ≥470MPa, and possesses excellent weldability, fatigue performance, and stamping performance. A cast aluminum mounting option is also available: this can improve weight reduction, but to achieve proper installation, the cast aluminum mounting will sacrifice the dynamic stiffness of the mounting point, resulting in poorer vibration isolation, and will also increase costs and production time.

[0038] The preload torque control of each bolt connection and the interference fit of the rubber bushing ensure the reliability of the bracket connection, which can meet the load transfer requirements of pickup trucks under complex working conditions such as full load, off-road, and impact. At the same time, it is compatible with conventional sheet metal processing technology such as stamping, bending, and laser welding, and has good mass production feasibility. There is no loosening or deformation at the connection points of the bracket, and the structural fatigue life is ≥100,000 cycles, which meets the service life requirements of the entire pickup truck.

[0039] All end plates are treated with cathodic electrophoretic coating, with a coating thickness of 20-30μm and a salt spray test time of ≥500h, effectively resisting corrosion from mud, water, and gravel during pickup truck operation and extending the service life of the bracket. The overall weight of the bracket is 4.2kg, a 15% reduction compared to traditional welded brackets, aligning with the trend of lightweight automotive development. In actual vehicle testing, this suspension bracket is compatible with front drive motors of different displacements, such as 2.0T and 2.4T, in pickup trucks. After assembly, the center positioning error of the motor is ≤0.5mm, the vibration isolation efficiency of the suspension system is ≥85%, and the NVH performance inside the vehicle is significantly improved, fully meeting the development needs of electric pickup trucks converted from gasoline engines.

[0040] During the production phase, assembly workers can install other components first, and then adjust the position of the suspension bracket as needed, reducing the incidence of assembly interference. In the after-sales phase, no welding work is required, and the time and cost of replacing the bracket are significantly reduced.

[0041] The assembly process is as follows: First, laser welding is performed on the left and right end plates 3. The positioning boss of the left end plate 2 is aligned with the positioning recess of the right end plate 3, achieving self-positioning through their own structures. No complex welding fixtures are needed; only simple positioning fixtures are required. After positioning, the welded ends are tightly fitted with a gap ≤0.03mm. Fiber laser welding equipment is used for splicing, with a welding power set to 3000W and a welding speed set to 3m / min. The welding path is evenly distributed along the mating ends, and the welding heat input is strictly controlled to reduce thermal deformation. Compared to traditional non-self-positioning welding methods, this structure reduces the offset of the mounting hole 18 after welding from ±0.5mm to within ±0.1mm, significantly improving batch product consistency, reducing tooling dependence, and increasing production efficiency.

[0042] After welding is completed, the press-fitting operation of the anti-friction ring 12 is carried out. The anti-friction ring 12 is press-fitted into the shallow grooves of all the mounting holes of the left end plate 2, the right end plate 3, and the lower end plate 4 one by one by using a special pneumatic press-fitting tooling. The press-fitting pressure is controlled within 0.2 - 0.3 MPa, and the press-fitting speed is set at 5 mm / s to ensure that the anti-friction ring 12 is completely embedded in the groove without warping, twisting, or damage on the surface. After the press-fitting is completed, a vision inspection device is used to conduct a full inspection of the installation state of the anti-friction ring 12 to ensure qualified installation.

[0043] After the assembly of the anti-friction ring 12 is completed, the bolt combination assembly of the bracket assembly is carried out. Place the horizontal section of the lower end plate 4 between the flanges at the lower parts of the left end plate 2 and the right end plate 3, and use a φ10 mm positioning pin for temporary positioning. The positioning pin and the mounting hole adopt an H7 / h6 clearance fit to ensure the alignment accuracy of the hole positions 18. After alignment, the fitting clearance between the flanges of the left and right end plates 3 and the horizontal section of the lower end plate 4 is ≤ 0.1 mm. Subsequently, insert M10×40 mm 8.8-grade high-strength bolts. Each set of bolts is equipped with a φ10 mm standard flat washer and a spring washer, and a torque wrench is used to evenly tighten them according to the calibrated torque of 45 N·m. The tightening process follows the diagonal cross sequence to avoid excessive local stress causing part deformation and ensure that the pre-tightening force of all bolts is uniform. After the bolts are tightened, a torque wrench is used for 100% re-tightening detection to ensure that the torque meets the standard.

[0044] After the assembly of the bracket assembly is completed, the vehicle-mounted assembly is carried out. Move the whole bracket to the designated installation position on the vehicle frame cross beam 1, align the vehicle frame mounting holes of the left end plate 2 and the right end plate 3 with the prefabricated threaded holes on the vehicle frame, and use M10×30 mm 8.8-grade high-strength bolts for screw connection and fixation. The tightening torque is set at 50 N·m, and it is also tightened following the diagonal cross sequence, and the re-tightening detection torque meets the standard. The screw connection method can flexibly adjust the installation angle and position according to the space conditions around the vehicle frame, effectively avoiding components such as pipelines, wire harnesses, and steering gears, and solving the problem of rigid layout of traditional welded brackets.

[0045] Subsequently, press-fit the front drive motor mount bushing into the mount installation position of the right end plate 3. The press-fitting pressure is controlled within 5 - 8 kN, and the press-fitting speed is set at 10 mm / s to ensure no relative sliding between the bushing and the bracket. After the press-fitting is completed, a pull-out force detection device is used to detect the press-fitting reliability, and a pull-out force ≥ 10 kN is qualified. Finally, fasten and connect the lower end plate 4 of the mount and the vertical section of the bracket lower end plate 4 with M10×35 mm 8.8-grade high-strength bolts, and the tightening torque is 40 N·m to complete the assembly of the entire mount system.

[0046] Static load transfer: The weight of the front drive motor, approximately 200kg, is transferred to the suspension rubber bushing through the motor housing. The bushing transfers the vertical static load to the mounting point of the suspension and rubber bushing on the right end plate 3. The right end plate 3 divides the load into two paths through its main structure: one path is transferred to the frame crossbeam 1 via the upper end plate, and the other path is transferred to the lower flanges of the left and right end plates 3 via the lower end plate 4. Finally, the load is transferred to the frame through the connection point between the left end plate 2 and the frame crossbeam 1, thus distributing the motor weight and avoiding overload at a single connection point.

[0047] Dynamic vibration load attenuation: When the drive motor is running, the torsional and reciprocating vibrations of the motor are initially attenuated by the suspension rubber bushing. The damping coefficient of the rubber bushing is 0.35. The remaining vibration load is transmitted to the right end plate 3 and then to the lower end plate 4 through the end plate and bolt connection. The lower end plate 4 can convert the horizontal vibration load into a bending moment. By dispersing the stress at the bend, it can effectively absorb the reverse vibration transmitted by the frame and avoid the vibration from resonating in the bracket. Finally, the vibration is dispersed to the entire chassis through the frame crossbeam 1, reducing the vibration transmission rate of the motor to below 15% and improving the driving smoothness and NVH performance of the pickup truck.

[0048] Comparative example: Traditional welded suspension brackets generally adopt a structure that is directly welded to the crossbeam 1 of the vehicle frame. The bracket installation position is completely fixed after welding and cannot be adjusted. It is difficult to avoid surrounding components such as brake lines, wiring harnesses, steering gears, and subframes around the vehicle frame. The compatibility with different vehicle configurations is poor, and the cost of layout modification is high. Moreover, the welded bracket and the vehicle frame form a non-removable whole. In the later stage, the bracket and suspension system cannot be disassembled separately. The only way to do this is to cut and re-weld. After-sales maintenance is difficult and costly, and it cannot meet the disassembly and maintenance needs of the front suspension of converted electric vehicles.

[0049] This application adopts a fully screw-in detachable structure to replace the traditional welding fixation, allowing for flexible adjustment of the installation position and effectively avoiding interference with surrounding pipes, wiring harnesses, steering gears, and other components on the vehicle frame, thus improving compatibility with different vehicle configurations. The bracket can be disassembled and replaced individually, reducing after-sales maintenance costs and meeting the disassembly and maintenance needs of the front suspension in converted electric vehicles. Each end plate is manufactured using conventional stamping, bending, and laser welding processes, requiring no additional parts or equipment, and without altering the original production process and assembly logic, resulting in low mass production costs and compatibility with existing production lines.

[0050] The existing bolt-on suspension brackets have rigid, direct contact surfaces made of pure steel. During vehicle operation, including driving, bumpy conditions, and acceleration / deceleration, relative micro-movements occur between the mounting surfaces, causing continuous metallic friction noise and severely impacting the vehicle's NVH performance. Furthermore, flatness deviations in the mounting surfaces lead to uneven distribution of bolt preload after tightening, resulting in localized bolt overload and insufficient preload in some bolts. Over long-term use, this can easily lead to loosening, bolt corrosion, and jamming, resulting in poor connection reliability. Additionally, the existing brackets have 18 mounting holes without sealing structures, allowing mud, salt, and impurities to easily enter the gaps between the mounting surfaces, causing corrosion of the bolts and mounting surfaces, further exacerbating the noise and connection failure risk, and shortening the bracket's service life.

[0051] This application uses a buffer pad and an embedded anti-friction ring 12 to block rigid metal contact, and the noise suppression rate of the mounting surface is ≥90%; the anti-friction ring 12 elastically compensates for the flatness deviation of the mounting surface, improves the uniformity of bolt preload by 40%, and does not loosen after long-term use; at the same time, it forms a ring-shaped sealing structure to prevent mud, water and salt from entering the mounting surface, and extends the service life of the bracket by more than 100%.

[0052] The buffer pad and anti-friction ring 12 alter the contact state of the mounting surface, creating a metal-elastomer contact. Under pressure, the elastomer deforms to adapt to the microscopic unevenness of the contact surface, resulting in a more uniform pressure distribution. The elastic properties of the anti-friction ring allow it to store elastic potential energy after the bolt is tightened. When the bolt loosens slightly due to vibration, the anti-friction ring releases some of this elastic potential energy, pushing the bolt back to its original position, achieving micro-movement self-locking. Simultaneously, the anti-friction ring forms a continuous annular contact around the bolt, preventing external moisture and dust from entering the threaded area and protecting the bolt from corrosion.

[0053] The existing screw-type brackets rely solely on a 4mm thick steel plate to ensure the dynamic stiffness of the mounting point, without any local reinforcement design. Some brackets have excessively reduced their structure in pursuit of lightweighting, resulting in the dynamic stiffness of the mounting point in the 20-200Hz core excitation frequency band of the powertrain not meeting the vibration isolation design requirements. Motor vibration and noise are directly transmitted to the chassis and cab through the bracket, causing NVH problems such as roaring and low-frequency howling inside the vehicle, which cannot meet the comfort requirements of electric vehicles converted from gasoline vehicles.

[0054] The bracket in this application is a structure with a steel base and a buffer pad. The buffer pad plays a damping role under dynamic excitation. Some of the vibration energy has been absorbed and attenuated by the rubber bushing and buffer pad before reaching the frame, which meets the design requirements for dynamic stiffness in the core frequency band of 20-200Hz. The motor vibration transmission rate is reduced to below 15%, the vibration isolation efficiency is ≥85%, and the NVH problems such as roaring and howling in the vehicle are improved, thereby improving the overall vehicle comfort.

[0055] This frame-based screw-connected powertrain mount structure solves the problems of inflexible layout and non-removable maintenance of traditional welded mounts. It enables fully screw-connected and detachable assembly of the mount and the frame, improving layout flexibility and after-sales maintainability. It also solves the problems of friction noise caused by rigid metal contact at the screw-connected mounting surface, uneven bolt preload, and poor connection reliability, achieving noise suppression and uniform preload distribution at the mounting surface. Furthermore, it addresses the issues of insufficient dynamic stiffness and poor vibration isolation performance at the mounting point, ensuring that the dynamic stiffness of the mounting point meets the vibration isolation design requirements in the 20-200Hz core frequency band, thereby improving the overall NVH performance of the vehicle.

[0056] In summary, by establishing a fully threaded, detachable connection between the left end plate 2, right end plate 3, and lower end plate 4, combined with the elastic buffering and sealing effect of the anti-friction ring 12, and the multi-directional load dispersion effect of the spatial frame structure, this frame-based threaded powertrain mount structure addresses the challenges of traditional mounts in terms of layout flexibility, noise reduction, and vibration isolation. It achieves these functions through a relatively simple combination of sheet metal parts, without relying on complex casting or forging processes, and possesses good cost controllability and mass production feasibility. This provides a practical mount solution for the electrification transformation of commercial vehicles such as pickup trucks. Since converted electric vehicles require rearranging the motor mounting points within a limited chassis space, higher demands are placed on the adaptability, adjustability, and NVH performance of the mount.

[0057] The present invention has been described above by way of example with reference to the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-described manner. Any non-substantial improvements made using the inventive concept and technical solution; or the direct application of the inventive concept and technical solution to other situations without modification, are all within the protection scope of the present invention.

Claims

1. A screw-type powertrain suspension bracket structure based on a vehicle frame, characterized in that: The frame includes a crossbeam (1), on which a left end plate (2), a right end plate (3) and a lower end plate (4) are connected. Both the left end plate (2) and the right end plate (3) are provided with mounting bolt connection holes (7). Both the left end plate (2) and the right end plate (3) are provided with connecting flanges (8). The lower end plate (4) is provided with a connecting part (11). One end of the connecting flange (8) and one end of the connecting part (11) are respectively connected to the top and bottom of the frame. The other end of the connecting flange (8) is connected to the other end of the connecting part (11).

2. The frame-based screw-in powertrain suspension bracket structure according to claim 1, characterized in that: The frame crossbeam (1) includes a first crossbeam plate (5) and a second crossbeam plate (6). Both the first crossbeam plate (5) and the second crossbeam plate (6) have a U-shaped cross-section structure. The outer edge of the first crossbeam plate (5) contacts the inner edge of the second crossbeam plate (6) and is fixedly connected. The top of the connecting flange (8) is connected to the top of the first crossbeam plate (5), and the connecting part (11) is connected to the bottom of the second crossbeam plate (6). Bolt holes (10) are provided at both ends of the connecting flange (8) and the connecting part (11).

3. The frame-based screw-in powertrain suspension bracket structure according to claim 2, characterized in that: The left end plate (2) and the right end plate (3) are symmetrically arranged. The axis of the suspension mounting bolt connection hole (7) is parallel to the length direction of the frame crossbeam (1). The suspension mounting bolt connection hole (7) is provided with a friction-reducing ring (12).

4. The frame-based screw-in powertrain mount structure according to claim 3, characterized in that: Both ends of the connecting flange and both ends of the lower end plate (4) are planar structures. A buffer pad installation gap (13) is provided between the top of the connecting flange (8) and the top of the first crossbeam plate (5). A buffer pad installation gap (13) is provided between the connecting part (11) and the second crossbeam plate (6). A buffer pad installation gap (13) is provided between the connecting flange (8) and the connecting part (11).

5. The frame-based screw-in powertrain mount structure according to claim 4, characterized in that: The top edge of the connecting flange (8) abuts against the edge of the second crossbeam plate (6); the top of the left end plate (2) and the right end plate (3) are both provided with folded edges (9), and the folded edges (9) of the left end plate (2) and the right end plate (3) are in contact and fixedly connected.

6. The frame-based screw-in powertrain mount structure according to claim 1, characterized in that: The lower end plate (4) is provided with a reinforcing rib (14) between the connecting part (11), and the connecting part (11) and the reinforcing rib (14) are both arched in cross-section.

7. The frame-based screw-in powertrain mount structure according to claim 6, characterized in that: The connecting part (11) and the reinforcing rib (14) form a wire passage (15), and the lower end plate (4) has a relief groove (16) in the middle of one end.

8. The frame-based screw-in powertrain suspension bracket structure according to claim 2, characterized in that: Multiple weight-reducing holes (17) are provided on the first crossbeam plate (5) and the second crossbeam plate (6), and multiple holes (18) are provided at equal intervals on the top of the first crossbeam plate (5) and the bottom of the second crossbeam plate (6).

9. The frame-based screw-in powertrain mount structure according to claim 2, characterized in that: The bolt holes (10) all have vertical openings.

10. A vehicle, characterized in that: Includes the frame-based screw-type powertrain suspension bracket structure as described in any one of claims 1-9.

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