Rear floor vehicle body structure

Abstract

The invention relates to the technical field of automobiles, and provides a rear floor automobile body structure which comprises a rear floor body, a middle cover plate, an activated carbon canister assembly and a transmission structure, a through hole is formed in the rear floor body, and the transmission structure and the middle cover plate are located on the two sides of the rear floor body respectively. The transmission structure corresponds to the position of the through hole and is in transmission connection with the two hubs, the middle cover plate is arranged on the through hole in a covering mode, a reserved space is formed by the middle cover plate and the through hole, and the carbon canister assembly is arranged in the reserved space. The transmission structure can enter the reserved space through the through hole, and a gap is formed between the transmission structure and the carbon canister assembly. Due to the existence of the reserved space and the reasonable layout and arrangement of the positions of the rear floor body, the flexible carbon canister assembly, the transmission structure and the middle cover plate, all the parts are not interfered with one another all the time, and the reliability of the whole rear floor system is improved.

Description

Technical Field

[0001] This invention belongs to the field of automotive technology, and specifically relates to a rear floor body structure. Background Technology

[0002] In the automotive technology field, four-wheel drive vehicles have become an important market segment due to their superior power performance and adaptability to complex road conditions. Among them, the driveshaft and carbon canister are key components of four-wheel drive vehicles, and their rational layout directly affects the vehicle's power transmission efficiency, assembly feasibility, and overall performance. The floor body serves as the core mounting and load-bearing foundation for both, and the spatial coordination design among these three components is one of the core challenges in the development of four-wheel drive vehicle chassis.

[0003] The driveshaft is a crucial transmission component in four-wheel drive vehicles, enabling power transfer from the transmission to the rear axle. Its core function is to efficiently transmit power to the rear wheels to achieve four-wheel drive. To ensure the stability and effectiveness of power transmission, the driveshaft must be precisely positioned under the vehicle chassis, while strictly avoiding interference with the movement of other chassis components (such as the suspension system and exhaust system). Interference can lead to power transmission losses, abnormal wear of components, and in severe cases, even compromise vehicle safety. However, due to the inherent complexity of four-wheel drive systems, the driveshaft's placement must balance optimized power transmission paths with space avoidance for multiple components, placing extremely high demands on the overall chassis space planning.

[0004] The carbon canister is a core device in the fuel system used to collect and store gasoline vapor. Its installation location must meet three key requirements: first, it must be close to the fuel system to shorten the vapor transmission path and ensure vapor recovery efficiency; second, it must have good ventilation to prevent gasoline vapor accumulation and potential safety hazards; and third, it must be compatible with the layout of other chassis components, without affecting normal vehicle assembly and functionality. Based on this, the rear floor area, due to its proximity to the fuel tank and relatively ample space, has become one of the mainstream candidate installation locations for the carbon canister. However, when arranging the carbon canister in the rear floor area, it is necessary to coordinate its spatial relationship with the driveshaft to avoid assembly conflicts caused by overlapping positions or excessive proximity.

[0005] In existing four-wheel drive vehicle designs, the layout of the rear floor unit, drive shaft, and carbon canister generally has significant flaws, mainly in the following two aspects: Firstly, space utilization efficiency is low. In early and some traditional designs, due to a lack of precise planning and coordinated optimization of the spatial relationship among the three elements, the rear floor often required a complex and fragmented structural design to avoid the power transmission path of the driveshaft and the installation space of the carbon canister. For example, this was achieved by adding local protrusions, recesses, or irregular cuts to create clearance. This design not only significantly reduced the space utilization of the rear floor but also increased the difficulty and cost of the stamping process. Furthermore, it left insufficient space for the subsequent placement of other chassis components, limiting the integrated development of the vehicle chassis.

[0006] Secondly, the rear floor structure suffers from uneven strength. As a crucial load-bearing structure at the rear of the vehicle, the continuity and integrity of its structural beams directly determine its overall strength and torsional resistance. However, in existing designs, to make room for the driveshaft and carbon canister, the structural beams of the rear floor are often interrupted in the clearance area or employ non-standard splicing, bending, or other special connection methods. This design disrupts the mechanical transmission path of the structural beams, resulting in weak points in the rear floor around the clearance area. This not only reduces the load-bearing capacity and durability of the rear floor but may also cause localized vibrations due to uneven stress during vehicle operation, further affecting the vehicle's overall performance.

[0007] Furthermore, with the iteration of automotive technology and the upgrading of consumer demands, the NVH (noise, vibration, and harshness) performance of vehicles has become one of the core competitive advantages. The driveshaft generates periodic vibrations during high-speed operation, and the carbon canister may also experience slight vibrations during the adsorption and desorption of gasoline vapors. The rear floor unit, as the direct mounting carrier for both, directly affects the vibration transmission path due to its layout. In existing designs, due to insufficient spatial matching between the rear floor unit, driveshaft, and carbon canister, vibrations are easily transmitted to the passenger compartment through the rear floor unit, leading to increased interior noise and intensified vibrations, significantly reducing the comfort and experience of passengers.

[0008] In summary, the current layout design of the rear floor unit, driveshaft, and carbon canister in four-wheel drive vehicles presents several challenges in terms of space utilization, structural strength, and NVH performance. Optimizing the spatial coordination among these three components to improve the space utilization efficiency and structural strength uniformity of the rear floor unit, while simultaneously reducing its negative impact on vehicle NVH performance, has become a critical technical bottleneck that needs to be overcome in the chassis design of four-wheel drive vehicles. Summary of the Invention

[0009] To address the aforementioned problems, this invention proposes a rear floor vehicle body structure, comprising: a rear floor body, a middle cover plate, an activated carbon canister assembly, and a transmission structure. A through hole is provided on the rear floor body. The transmission structure and the middle cover plate are respectively located on both sides of the rear floor body, and the transmission structure corresponds to the position of the through hole and is connected to the two wheel hubs. The middle cover plate covers the through hole and forms a reserved space with it. The activated carbon canister assembly is disposed within the reserved space. The transmission structure can enter the reserved space through the through hole and is spaced apart from the activated carbon canister assembly.

[0010] Optionally, the middle cover plate is a raised structure with a receiving cavity, the receiving cavity facing the through hole and forming the reserved space with the through hole.

[0011] Optionally, multiple reinforcing structures are provided along the outer circumferential direction of the middle cover plate.

[0012] Optionally, it also includes a spare tire bracket, with a fixing position provided in the central area of ​​the outer wall of the middle cover plate, and the spare tire bracket is located at the fixing position.

[0013] Optionally, it also includes a carbon canister mounting bracket, which is disposed in the receiving cavity, and the activated carbon canister assembly is mounted on the carbon canister mounting bracket. The transmission structure is spaced apart from the carbon canister mounting bracket and does not contact it.

[0014] Optionally, multiple reinforcing structures are concave rib structures, and the depth of the concave rib structure is 3-5mm, and the width of the concave rib structure is 5-10mm.

[0015] Optionally, the concave rib structure can be designed to be arc-shaped or trapezoidal.

[0016] Optionally, three layers of reinforcing ribs are provided on the bottom surface of the rear floor body, and the three layers of reinforcing ribs are arranged at intervals along the force direction of the rear floor body.

[0017] Optionally, the height of the three layers of reinforcing ribs is 3-5mm, and the width of the three layers of reinforcing ribs is 9-11mm.

[0018] Optionally, it also includes a carbon canister guide block, which is fixed to the carbon canister mounting bracket and forms a guide groove. The activated carbon canister assembly is pushed along the guide groove to the top of the guide groove and then fixedly connected to the carbon canister mounting bracket by bolts.

[0019] The rear floor vehicle structure provided by this invention has the following advantages compared with the prior art: The activated carbon canister assembly is housed within a reserved space. The transmission structure can enter this space through a through-hole, maintaining a distance from the activated carbon canister assembly. Even if the transmission structure does enter the reserved space, the existence of this space, along with the rational layout of the rear floor body, activated carbon canister assembly, transmission structure, and center cover, ensures that there is no interference between the components, thus improving the reliability of the entire rear floor system. Furthermore, the rational layout of the activated carbon canister assembly, transmission structure, and center cover effectively improves the utilization efficiency of the space beneath the rear floor, making the entire rear floor system more compact.

[0020] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures pointed out in the description and the drawings. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 A schematic diagram of the rear floor vehicle body structure in an embodiment of the present invention is shown; Figure 2 An exploded frontal view of the rear floor vehicle body structure in an embodiment of the present invention is shown; Figure 3 It shows Figure 2 Diagram of the explosion from the back; Figure 4 A schematic diagram of the mounting bracket for the rear floor vehicle body structure in an embodiment of the present invention is shown.

[0023] In the diagram, 1 is the rear floor body; 10 is the through hole; 2 is the middle cover plate; 21 is the reinforcing structure; 22 is the fixing position; 3 is the activated carbon canister assembly; 4 is the transmission structure; 5 is the spare tire bracket; 6 is the carbon canister mounting bracket; and 61 is the carbon canister guide block. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] like Figure 1 As shown, the present invention provides a rear floor vehicle body structure, including: a rear floor body 1, a middle cover plate 2, an activated carbon canister assembly 3, and a transmission structure 4. See details below. Figure 2 and Figure 3 A through hole 10 is provided on the rear floor body 1. The transmission structure 4 and the middle cover plate 2 are located on both sides of the rear floor body 1, and the transmission structure 4 corresponds to the position of the through hole 10 and is connected to the two wheel hubs. The middle cover plate 2 covers the through hole 10 and forms a reserved space with the through hole 10. The activated carbon canister assembly is located in the reserved space. The transmission structure 4 can enter the reserved space through the through hole 10 and is spaced apart from the activated carbon canister assembly. By reasonably arranging the positions between the middle cover plate 2, the activated carbon canister assembly 3, and the transmission structure 4, the gap between the activated carbon canister assembly 3 and the transmission structure 4 is required to be greater than 40mm to prevent interference between the transmission structure 4 and the activated carbon canister assembly 3 during operation. The activated carbon canister assembly 3 is a square box component. The front of the transmission structure 4 is connected to the engine drive shaft, and the left and right sides are connected to the chassis components, providing power to the rear tires of the vehicle and driving the rear wheels to rotate. This effectively improves the utilization efficiency of the space under the rear floor and makes the entire rear floor system more compact. The activated carbon canister assembly 3 is installed in a suitable position, which is conducive to its normal function. Furthermore, the reserved space allows for coordination between the components, reduces mutual interference between components, and improves the reliability of the entire rear floor system.

[0026] It should be noted that the rear floor body 1, the middle cover plate 2, and the fixing bracket are made of DC01 steel with a yield strength of not less than 160MPa. This steel possesses excellent drawing toughness, meeting the high-depth drawing requirements of complex shapes such as the rear floor body 1 and the middle cover plate 2. It also ensures machinability and weldability, preventing cracking during stamping and forming a strong joint during welding, thus guaranteeing the overall load-bearing strength of the rear floor. When selecting materials, the machinability and weldability of the steel must also be considered. This ensures that the steel can be easily stamped, bent, and formed during manufacturing, and that a strong weld joint can be formed during welding.

[0027] Rear floor body 1: integrally formed using a high-precision stamping process. The stamping die is designed with through-hole 10 structures based on the motion trajectory and dimensional parameters (such as drive shaft diameter and swing amplitude) of the transmission structure 4. After placing DC01 steel sheet into the die, a pressure of 300-500 MPa is applied using a press to cause plastic deformation of the steel, precisely forming the through-hole 10 structure that matches the transmission structure 4. The middle cover plate 2 assembly is manufactured using a combination of stamping and welding processes. First, the basic shape of the middle cover plate 2 is manufactured using a stamping process, including the welding positions for the spare tire bracket 5 and the carbon canister mounting bracket 6. Then, the spare tire bracket 5 and the carbon canister mounting bracket 6 are connected using a welding process. Furthermore, the middle cover plate 2 is fixed to the rear floor body 1 by welding, and a sealing strip is provided at the weld joint; the weld points of the middle cover plate 2 and the rear floor body 1 are evenly distributed, and the torque borne by the weld points is not less than 6000 N·m.

[0028] In one embodiment, the middle cover plate 2 is a raised structure with a receiving cavity facing the through hole 10 and forming a reserved space with the through hole 10. It should be noted that the middle cover plate 2 is manufactured using a combination of stamping and welding processes. First, the basic shape of the middle cover plate 2, i.e., the raised structure, is manufactured using a stamping process, with reserved welding positions for the spare tire bracket 5 and the carbon canister mounting bracket 6 within the receiving cavity. Then, the spare tire bracket 5 and the carbon canister mounting bracket 6 are connected using a welding process. The receiving cavity is also formed using a stamping process. The raised structure not only creates the reserved space but also provides support.

[0029] In one embodiment, a plurality of reinforcing structures 21 are provided along the circumferential direction of the outer wall of the middle cover plate 2. The plurality of reinforcing structures 21 can better disperse stress, significantly improve the structural strength of the part, and thus be able to withstand sufficient force to better withstand various loads during vehicle operation.

[0030] like Figure 2As shown, in one embodiment, a spare tire bracket 5 is also included. A fixing position 22 is provided in the central area of ​​the outer wall of the middle cover plate 2, and the spare tire bracket 5 is disposed on the fixing position 22. It should be noted that a buffer pad is also included. The buffer pad is disposed around the fixing position 22 on the middle cover plate 2. The buffer pad is made of rubber material and has a thickness of 1-2 cm. The spare tire is fixed to the spare tire bracket 5 by bolts, and the spare tire bracket 5 is welded to the middle cover plate 2. After being formed by a stamping process, the spare tire bracket 5 is welded to the middle cover plate 2. The bracket has pre-drilled holes for spare tire fixing bolts (hole diameter 12-14 mm), and the hole position tolerance is controlled within ±0.1 mm to ensure the coaxiality of the spare tire during installation. The function of the buffer pad is to reduce the noise generated by the spare tire due to vibration during vehicle operation and to prevent the spare tire from causing wear on the middle cover plate 2 assembly. The spare tire is placed on the spare tire bracket 5 and is bolted to the spare tire bracket 5. The spare tire bracket 5 and the middle cover plate 2 assembly are welded together to prevent the spare tire from shaking during vehicle operation.

[0031] In one embodiment, a carbon canister mounting bracket 6 is also included. The carbon canister mounting bracket 6 is disposed within the receiving cavity, and the activated carbon canister assembly 3 is mounted on the carbon canister mounting bracket 6. The transmission structure 4 maintains a distance from the carbon canister mounting bracket 6 and does not contact it. The carbon canister mounting bracket 6 is formed by a stamping process, first by drawing, then trimming and punching, and finally by shaping to ensure that the actual part matches the design state. The part material is low-strength steel, which provides both the carbon canister mounting function and ensures the transition design of material properties. The carbon canister mounting bracket 6 has a raised surface in the middle of its profile and a rectangular hole, which provides initial guidance during carbon canister installation. The lower surface of the carbon canister mounting bracket 6 has four welding surfaces for welding to the rear floor body. The upper large surface has two projected weld nuts to provide mounting points for the carbon canister. The carbon canister mounting bracket 6 is made of low-strength steel, which provides stable carbon canister mounting support and achieves the transition design of material properties, avoiding stress concentration due to excessive material strength difference when welding with the middle cover plate 2, while reducing the weight of the bracket itself, meeting the vehicle's lightweight requirements.

[0032] In one embodiment, multiple reinforcing structures 21 are concave rib structures, with a depth of 3-5 mm and a width of 5-10 mm. It should be noted that six concave rib structures are manufactured on the middle cover plate 2 using a stamping process. While stamping the basic shape of the middle cover plate 2, the concave ribs are stamped onto the middle cover plate 2 using a special shape on the mold. They are evenly distributed along the length of the middle cover plate 2 (with a spacing of 150-200 mm between adjacent concave rib structures) to achieve stress dispersion. After forming, the depth, width, and distribution position of the concave ribs are detected using a coordinate measuring machine to ensure that they meet the design requirements of a depth of 3-5 mm and a width of 5-10 mm, and that the deviation in spacing between adjacent concave ribs is ≤2 mm.

[0033] In one embodiment, the concave rib structure is designed to be arc-shaped or trapezoidal. By evenly arranging the concave rib structure on the middle cover plate 2, this shape can better disperse stress. When subjected to external force, the stress of the arc-shaped concave rib can be evenly distributed along the arc-shaped surface, reducing stress concentration.

[0034] In one embodiment, three layers of reinforcing ribs are provided on the bottom surface of the rear floor body 1, and the three layers of reinforcing ribs are arranged at intervals along the force direction of the rear floor body 1. It should be noted that these three layers further enhance the structural strength of the rear floor body 1, enabling it to better withstand various loads during vehicle operation. With the development of automotive technology, the performance requirements for automotive components are also increasing. In terms of modal requirements, it is necessary to meet the 30Hz modal requirement to ensure vehicle stability and comfort, and the reinforcing ribs play a very good strengthening role.

[0035] In one embodiment, the height of the three reinforcing ribs is 3-5mm, and the width of the three reinforcing ribs is 9-11mm. It should be noted that the reinforcing ribs, with a height of 3-5mm and a width of 10mm, are arranged at intervals (80-100mm spacing) along the longitudinal force direction of the rear floor body 1. After molding, modal testing is performed to verify that the modal frequency of the rear floor assembly is not lower than 30Hz, meeting the requirements for vehicle stability and comfort. The test uses a vibrator excitation method, collecting vibration data at multiple measuring points on the vehicle body, and confirming that the modal frequency meets the standard through data analysis.

[0036] like Figure 4 As shown, in one embodiment, a carbon canister guide block 61 is also included. The carbon canister guide block 61 is fixed to the carbon canister mounting bracket 6 and forms a guide groove. After the activated carbon canister assembly 3 is pushed along the guide groove to the top position of the guide groove, it is fixedly connected to the carbon canister mounting bracket 6 by bolts. Optionally, the guide groove has a convex shape. It should be noted that during installation, the carbon canister guide block is first installed on the carbon canister mounting bracket 6, and then pushed along the guide groove (along the X direction of the guide groove, where the X direction is the length direction of the vehicle body) to the top position of the guide groove. That is, the activated carbon canister assembly 3 is first pushed along the larger groove of the guide groove until the smaller groove is pushed in, thus initially determining the position of the activated carbon canister assembly 3. Then, the carbon canister is fixed to the mounting bracket 6 with bolts. A total of 2 mounting bolts are used. The carbon canister guide block 61 can fix the activated carbon canister assembly 3 in a predetermined position. When the transmission structure 4 is installed, there is a gap between the activated carbon canister assembly 3 and the transmission structure 4, and the heights of the positions are also different, so that the two will not interfere with each other. The bolt specifications should be selected based on the weight of the carbon canister and the vibration during vehicle operation. M6 mounting bolts are used, with a tightening torque between 15-25 N·m. Since the carbon canister mounting bracket 6 provides a carbon canister mounting point between itself and the middle cover plate 2, the carbon canister mounting bracket 6 is recessed in the middle to provide a pre-drilled mounting hole for the carbon canister. The mounting surface of the carbon canister is locally modified to ensure its strength. Features are also made around the perimeter for welding to the middle cover plate 2.

[0037] In summary, by rationally arranging the spare tire and carbon canister on the top and inside of the center cover plate 2 assembly, the utilization efficiency of the space under the rear floor body 1 is effectively improved, making the entire rear floor body 1 system more compact.

[0038] The concave rib structure of the middle cover plate 2 and the structural rib design of the rear floor body 1 significantly improve the structural strength of the parts, can stably meet the modal requirements of 30HZ, and improve the stability and comfort of the vehicle.

[0039] The carbon canister is installed in a suitable position to ensure its proper functioning and to coordinate with the layout of the rear floor body 1 and the spare tire, reducing mutual interference between components. Due to the reserved space and the reasonable layout of the rear floor body 1, the carbon canister assembly, the transmission structure 4, and the center cover 2, interference between components is prevented, improving the reliability of the entire rear floor system.

[0040] The rear floor body structure of this application is mainly adapted to four-wheel drive models. Compared with two-wheel drive models, by adjusting the carbon canister installation position to inside the rear floor cover 2, the space occupied by the fuel tank under the floor of the four-wheel drive model is avoided, realizing the compatible layout of the four-wheel drive system and fuel system components. No major modifications to the body frame are required, and it has good platform adaptability.

[0041] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A rear floor vehicle body structure, characterized in that, include: The rear floor body (1), the middle cover plate (2), the activated carbon canister assembly (3), and the transmission structure (4) are provided. The rear floor body (1) is provided with a through hole (10). The transmission structure (4) and the middle cover plate (2) are located on both sides of the rear floor body (1). The transmission structure (4) is positioned corresponding to the through hole (10) and is connected to the two wheel hubs. The middle cover plate (2) covers the through hole (10) and forms a reserved space with the through hole (10). The activated carbon canister assembly is located in the reserved space. The transmission structure (4) can enter the reserved space through the through hole (10) and is spaced apart from the activated carbon canister assembly.

2. The rear floor vehicle structure according to claim 1, characterized in that, The middle cover plate (2) has a raised structure with a receiving cavity. The receiving cavity faces the through hole (10) and forms the reserved space with the through hole (10).

3. The rear floor vehicle structure according to claim 1, characterized in that, Multiple reinforcing structures (21) are provided along the outer circumference of the middle cover plate (2).

4. The rear floor vehicle body structure according to claim 1, characterized in that, It also includes a spare tire bracket (5), with a fixing position (22) provided in the central area of ​​the outer wall of the middle cover plate (2), and the spare tire bracket (5) is located on the fixing position (22).

5. The rear floor vehicle structure according to claim 2, characterized in that, It also includes a carbon canister mounting bracket (6), which is disposed in the receiving cavity, the activated carbon canister assembly (3) is mounted on the carbon canister mounting bracket (6), and the transmission structure (4) maintains a distance from the carbon canister mounting bracket (6).

6. The rear floor vehicle body structure according to claim 3, characterized in that, The multiple reinforcing structures (21) are concave rib structures, and the depth of the concave rib structure is 3-5mm, and the width of the concave rib structure is 5-10mm.

7. The rear floor vehicle structure according to claim 6, characterized in that, The concave rib structure is designed to be arc-shaped or trapezoidal.

8. The rear floor vehicle structure according to claim 1, characterized in that, Three layers of reinforcing ribs are provided on the bottom surface of the rear floor body (1), and the three layers of reinforcing ribs are arranged at intervals along the force direction of the rear floor body (1).

9. The rear floor vehicle structure according to claim 8, characterized in that, The height of the three layers of reinforcing ribs is 3-5mm, and the width of the three layers of reinforcing ribs is 9-11mm.

10. The rear floor vehicle structure according to claim 5, characterized in that, It also includes a carbon canister guide block (61), which is fixed on the carbon canister mounting bracket (6) and forms a guide groove. The activated carbon canister assembly (3) is pushed along the guide groove to the top of the guide groove and then fixedly connected to the carbon canister mounting bracket (6) by bolts.

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