Automobile rear floor framework

Abstract

The invention relates to the technical field of automobile body-in-white structures, in particular to an automobile rear floor framework which comprises a framework body, the framework body is integrally formed by a front cross beam, a rear cross beam and two side beams, the middle portions of the side beams are concave downwards to form a first U-shaped groove, and the middle portions of the front cross beam and the rear cross beam are concave downwards to form a second U-shaped groove and a third U-shaped groove respectively. The first U-shaped groove communicates with the second U-shaped groove and the third U-shaped groove, a reinforcing plate is arranged on the inner wall of the front side of the first U-shaped groove, a first splicing groove is formed in the side wall, away from the front cross beam, of the side beam, a protection plate matched with the first splicing groove is arranged at the first splicing groove, and a second splicing groove is formed in the bent position, connected with the front cross beam, of the side beam. The second splicing groove is provided with a connecting plate matched with the second splicing groove, the connecting plate is located on the side wall, close to the rear cross beam, of the second U-shaped groove, and the reinforcing plate, the protection plate and the connecting plate are all connected with the framework body through the hot forming patch plate technology. The weight of the vehicle body can be effectively reduced, and the torsional rigidity of the vehicle body is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of automotive body-in-white structures, and particularly to an automotive rear floor skeleton. Background Art

[0002] The body-in-white is a key component for passive safety in vehicle collisions, and passive safety refers to the protection of vehicle occupants after an accident. The body-in-white parts need to have a reasonable layout of the body skeleton on the premise of sufficient material strength to meet the requirements of various collision conditions. Torsional stiffness is one of the important properties of the body-in-white. If the torsional stiffness of the body is too low or insufficient, it will cause the vehicle to deform during driving, leading to problems such as body cracking, abnormal noises, looseness, and poor part fit clearance, reducing the driving smoothness, comfort, and reliability of the whole vehicle.

[0003] Automotive lightweighting is not simply reducing the vehicle body weight but a systematic project integrating aspects such as vehicle body collision, torsional stiffness, process performance, economy, and environmental protection. The design of the body-in-white needs to meet multiple property requirements such as stiffness, safety, weight, strength, and mode simultaneously. The lightweighting, high-strengthening, and integration of the body structure are the general trend. Compared with the main load-bearing skeleton parts formed by the lap joint of crossbeams and longitudinal beams on the front and rear floors of the occupant compartment, the form of a safety body is that the passenger compartment structure is firm, with extremely small deformation during an accident, fully ensuring the survival space of the internal occupants. At the same time, the front and rear of the vehicle body can deform during a collision to absorb energy and reduce the impact on the occupants.

[0004] Professionally, the elastic modulus is a physical index describing the elastic recovery ability of a material, measuring the ability of a material to generate strain when being pulled or compressed, that is, the rigidity degree of the material. Among them, the elastic modulus of steel is about 206 GPa, and the elastic modulus of aluminum is only about 70 GPa. This means that under the same cross-sectional area, the same material thickness, and the same load, the deformation of aluminum parts is much larger than that of steel parts. If aluminum is used as the body load-bearing skeleton part, to ensure the survival space of the members during the collision process, larger cross-sections and thicknesses are often required, resulting in an increase in cost and weight. On the other hand, the sheet metal performance of aluminum is poor, and its strong thermal conductivity leads to poor weldability and easy cracking. When applied to the body-in-white, the sheet metal after-sales performance is too poor, and the maintenance cost for the vehicle owner is high. Summary of the Invention

[0005] In order to solve the above technical problems, the present invention provides an automotive rear floor skeleton.

[0006] The present invention adopts the following technical solutions: An automotive rear floor skeleton, including a skeleton main body, which is integrally formed by a front cross member, a rear cross member and two side beams. The skeleton main body is an axisymmetric structure, and the axis of symmetry is parallel to the vehicle body direction. The middle part of the side beam is recessed to form a first U-shaped groove. The middle parts of the front cross member and the rear cross member are recessed to form a second U-shaped groove and a third U-shaped groove respectively. The first U-shaped groove is communicated with the second U-shaped groove and the third U-shaped groove respectively. A reinforcing plate is provided on the inner wall of the front side of the first U-shaped groove. A first splicing groove is provided on the side wall of the side beam away from the front cross member. A protective plate adapted to it is provided at the first splicing groove. A second splicing groove is provided at the bent part where the side beam is connected to the front cross member. An adapter plate adapted to it is provided at the second splicing groove. The adapter plate is located on the side wall of the second U-shaped groove close to the rear cross member. The reinforcing plate, the protective plate and the adapter plate are all connected to the skeleton main body by means of a hot forming patch plate process. The skeleton main body is made of ultra-high strength steel.

[0007] For the automotive rear floor skeleton of an embodiment of the present invention, by setting the integrally formed skeleton main body, the number of parts connected between the front cross member, the rear cross member and the two side beams is effectively reduced, the production steps are simplified, and the production cost is reduced; the settings of the first U-shaped groove, the second U-shaped groove and the third U-shaped groove can initially ensure the mechanical strength of the skeleton main body. The designs of the reinforcing plate, the protective plate and the adapter plate can accurately locally strengthen the weak areas of the rear floor without thickening the whole rear floor, effectively reducing the quality of the rear floor. In addition, the hot forming patch plate process can make the reinforcing plate, the protective plate and the adapter plate integrally formed with the skeleton main body, so that the load-bearing capacity of the rear floor is much greater than the joint transition of the traditional structure, effectively improving the torsional stiffness of the vehicle body; finally, the ultra-high strength steel can ensure the physical basis for the high torsional stiffness of the rear floor. Combined with the integral forming technology and the lightweight design, it can effectively reduce the vehicle body weight and improve the torsional stiffness of the vehicle body.

[0008] Further, the cross section of the reinforcing plate is in a U-shaped structure. The two side walls of the reinforcing plate are respectively connected to the two inner walls of the first U-shaped groove, and the bottom wall of the reinforcing plate is connected to the inner wall of the bottom surface of the first U-shaped groove. A convex plate that bends towards the middle of the first U-shaped groove is provided on the side wall of the reinforcing plate away from the front cross member. The convex plate is integrally formed with the reinforcing plate.

[0009] Further, a plurality of strengthening grooves are provided on the bottom wall of the reinforcing plate in a staggered distribution. The lower end of the convex plate abuts against the bottom of the strengthening groove away from the front cross member.

[0010] Further, reinforcing ribs are also provided on the bottom wall of the reinforcing plate. The positions of the reinforcing ribs correspond to the downward bending parts of the side beams.

[0011] Further, the thickness of the reinforcing plate is 1.5 to 2 times the blank thickness of the main body of the framework.

[0012] Further, one end of the protection plate is connected to the inner side wall of the first U-shaped groove, and the other end of the protection plate is connected to the outer side wall of the first U-shaped groove.

[0013] Further, a first positioning groove is provided on the inner wall of the first U-shaped groove away from the front cross beam, a second positioning groove corresponding to the first positioning groove is provided on the protection plate, and the second positioning groove is partially embedded in the first positioning groove and is adapted thereto.

[0014] Further, the thicknesses of the protection plate and the connection plate are 1.1 to 1.3 times the blank thickness of the main body of the framework.

[0015] Further, a connection plate is further provided in the first U-shaped groove. Two ends of the connection plate are respectively fixedly connected to the two inner side walls of the first U-shaped groove. The position of the connection plate corresponds to the connection part between the side beam and the front cross beam.

[0016] Further, a positioning pin is provided on the connection plate. The positioning pin sequentially penetrates through the connection plate, the reinforcing plate and the side beam from top to bottom. Two ends of the positioning pin are respectively fixedly connected to the connection plate and the side beam. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0018] Figure 1 is a schematic structural view of the automotive rear floor framework of the present invention;

[0019] Figure 2 is a schematic structural view of the main body of the framework in the automotive rear floor framework of the present invention;

[0020] Figure 3 is a schematic structural view of the reinforcing plate in the automotive rear floor framework of the present invention;

[0021] Figure 4 is a schematic structural view of the protection plate in the automotive rear floor framework of the present invention;

[0022] Figure 5 is a schematic structural view of the connection plate in the automotive rear floor framework of the present invention.

[0023] Description of the reference numerals:

[0024] 1. Skeleton body; 10. Side beam; 11. First U-shaped groove; 111. First positioning groove; 12. Reinforcement plate; 121. Convex plate; 122. Strengthening groove; 123. Reinforcement rib; 13. First splicing groove; 14. Protective plate; 141. Second positioning groove; 15. Second splicing groove; 16. Connecting plate; 17. Connecting plate; 18. Positioning pin; 20. Front cross beam; 21. Second U-shaped groove; 30. Rear cross beam; 31. Third U-shaped groove. DETAILED DESCRIPTION

[0025] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the embodiments of the present invention, and should not be construed as limiting the present invention.

[0026] In the description of the embodiments of the present invention, it should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0027] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0028] In the embodiments of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like 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 or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0029] Reference Figures 1 to 5, in an embodiment of the present invention, an automotive rear floor skeleton includes a skeleton main body 1, which is integrally formed by a front cross beam 20, a rear cross beam 30 and two side beams 10. The skeleton main body 1 is an axisymmetric structure, and the axis of symmetry is parallel to the vehicle body direction. The middle part of the side beam 10 is concave to form a first U-shaped groove 11. The middle parts of the front cross beam 20 and the rear cross beam 30 are concave to form a second U-shaped groove 21 and a third U-shaped groove 31 respectively. The first U-shaped groove 11 communicates with the second U-shaped groove 21 and the third U-shaped groove 31 respectively. A reinforcing plate 12 is provided on the front inner wall of the first U-shaped groove 11. A first splicing groove 13 is provided on the side wall of the side beam 10 away from the front cross beam 20. A protective plate 14 adapted to the first splicing groove 13 is provided at the first splicing groove 13. A second splicing groove 15 is provided at the bent part where the side beam 10 is connected to the front cross beam 20. An adapter plate 16 adapted to the second splicing groove 15 is provided at the second splicing groove 15. The adapter plate 16 is located on the side wall of the second U-shaped groove 21 close to the rear cross beam 30. The reinforcing plate 12, the protective plate 14 and the adapter plate 16 are all connected to the skeleton main body 1 by means of a hot forming patch plate process. The skeleton main body 1 is made of ultra-high strength steel.

[0030] In the automotive rear floor skeleton according to an embodiment of the present invention, by setting the integrally formed skeleton main body 1, the number of parts connected between the front cross beam 20, the rear cross beam 30 and the two side beams 10 is effectively reduced, the production steps are simplified, and the production cost is reduced; the settings of the first U-shaped groove 11, the second U-shaped groove 21 and the third U-shaped groove 31 can initially ensure the mechanical strength of the skeleton main body 1. The designs of the reinforcing plate 12, the protective plate 14 and the adapter plate 16 can accurately locally strengthen the weak areas of the rear floor, without thickening the whole rear floor, effectively reducing the quality of the rear floor. In addition, the hot forming patch plate process can make the reinforcing plate 12, the protective plate 14 and the adapter plate 16 integrally formed with the skeleton main body 1, so that the load-bearing capacity of the rear floor is much greater than the joint transition in the traditional structure, effectively improving the torsional stiffness of the vehicle body; finally, the ultra-high strength steel can ensure the physical basis for the high torsional stiffness of the rear floor. Combined with the integral forming technology and lightweight design, it can effectively reduce the vehicle body weight and improve the torsional stiffness of the vehicle body.

[0031] Different from the selection of aluminum in the integral die casting, the present invention selects hot formed steel to integrate multiple parts into a single part, avoiding the poor maintainability of aluminum and greatly simplifying the manufacturing and logistics costs generated by the sub-parts; and through finite element analysis, combined with different working conditions, the theoretical strength and strengthening areas on the structure can be quantitatively analyzed. Combined with the patch plate process of hot forming stamping, accurate local strengthening can be carried out to avoid the weight increase caused by the traditional rough overall thickening, greatly reducing the design redundancy; after calculation, the total weight of the rear floor skeleton assembly is reduced by about 17%, but still 100% meets the requirements of safety collision; moreover, the whole large part is integrally formed, avoiding the welding process of the traditional rear floor skeleton, and the overall load-bearing capacity of the part body is much greater than the joint transition in the structure. After testing, the torsional stiffness of the vehicle body can be increased by about 10%.

[0032] In this embodiment, the thickness of the blank of the skeleton main body 1 is less than that of the traditional rear floor skeleton; the hot forming patch panel process refers to a complex hot stamping forming technology in which two hot stamping steel blank with different shapes and sizes are subjected to planar spot welding and then heated to 930°C to 950°C and held, and then the stamping forming and quenching processes are completed in a mold. The specific process flow is well-known to those skilled in the art, so it will not be described in detail here.

[0033] The cross-section of the reinforcing plate 12 is in a U-shaped structure. The two side walls of the reinforcing plate 12 are respectively connected to the inner walls of the two sides of the first U-shaped groove 11, and the bottom wall of the reinforcing plate 12 is connected to the inner wall of the bottom surface of the first U-shaped groove 11. A convex plate 121 that bends toward the middle of the first U-shaped groove 11 is provided on the side wall of the reinforcing plate 12 away from the front cross beam 20, and the convex plate 121 is integrally formed with the reinforcing plate 12; the U-shaped structure of the reinforcing plate 12 can support the two side walls of the side beam 10, and the structure of the convex plate 121 can further improve the protection of the reinforcing plate 12 for the side wall of the side beam 10 away from the front cross beam 20. Since the side wall of the side beam 10 away from the front cross beam 20 is the first stress-bearing surface when the vehicle body encounters a collision, it is particularly important to ensure its strength; in this embodiment, the structural dimensions of the convex plate 121 are adapted to the inner wall of the first U-shaped groove 11 and are not of the same size.

[0034] A plurality of strengthening grooves 122 are provided on the bottom wall of the reinforcing plate 12 and are distributed in a staggered manner. The lower end of the convex plate 121 abuts against the bottom of the strengthening groove 122 away from the front cross beam 20; the strengthening grooves 122 can prevent the reinforcing plate 12 from deforming under stress, can disperse the stress received by the reinforcing plate 12, and the strengthening grooves 122 can cooperate with the convex plate 121 in terms of position, thereby further improving the strength of the reinforcing plate 12 and the performance of absorbing the impact force of the vehicle body during a collision; in this embodiment, two rows of strengthening grooves 122 are provided, and the two rows of strengthening grooves 122 are staggered from each other, so that the reinforcing plate 12 can evenly absorb the collision stress and avoid local fracture or overall deformation.

[0035] Reinforcing ribs 123 are also provided on the bottom wall of the reinforcing plate 12, and the positions of the reinforcing ribs 123 correspond to the downward bending parts of the side beam 10; the downward bending parts of the side beam 10 are also the weak parts of the rear floor. After the vehicle body is collided, the rear floor is prone to fracture and distortion at this place. The design of the reinforcing plate 12 combined with the strengthening of the reinforcing ribs 123 can effectively improve the torsional stiffness of the downward bending parts of the side beam 10; in this embodiment, the reinforcing ribs 123 are strip-shaped and are in the same extending direction as the side beam 10; the position of the reinforcing plate 12 corresponds to the connection part of the side beam 10 and the front cross beam 20, the strengthening grooves 122 are located in the middle of the reinforcing plate 12, and the reinforcing ribs 123 are located at the rear side of the reinforcing plate 12.

[0036] The thickness of the reinforcing plate 12 is 1.5 to 2 times the blank thickness of the main body 1 of the framework. Since the blank thickness of the main body 1 of the framework is less than the thickness of the traditional rear floor, it is necessary to increase the thickness of the patch plate to precisely strengthen the weak area of the main body 1 of the framework. Through finite element analysis, the position where the reinforcing plate 12 is located is the core of the strength of the side beam 10. Therefore, the thickness of the reinforcing plate 12 is relatively thick. In this embodiment, the thickness of the reinforcing plate 12 is 1.5 times the blank thickness of the main body 1 of the framework.

[0037] One end of the protective plate 14 is connected to the inner side wall of the first U-shaped groove 11, and the other end of the protective plate 14 is connected to the outer side wall of the first U-shaped groove 11. The connection structure between the protective plate 14 and the first U-shaped groove 11 can improve its connection stability and ensure that the protective plate 14 can play the role of enhancing the strength of the side wall of the side beam 10 far from the front cross beam 20. A first positioning groove 111 is provided on the inner wall of the first U-shaped groove 11 far from the front cross beam 20, and a second positioning groove 141 corresponding to the first positioning groove 111 is provided on the protective plate 14. The second positioning groove 141 is partially embedded in the first positioning groove 111 and is adapted to it. By embedding the second positioning groove 141 into the first positioning groove 111, the protective plate 14 can be quickly assembled with the first splicing groove 13, and the first positioning groove 111 and the second positioning groove 141 can further improve the connection stability between the protective plate 14 and the first splicing groove 13. In this embodiment, the second positioning groove 141 is located in the middle and lower part of the protective plate 14.

[0038] The thickness of the protective plate 14 and the connecting plate 16 is 1.1 to 1.3 times the blank thickness of the main body 1 of the framework. In this embodiment, the thickness of the protective plate 14 and the connecting plate 16 is 1.2 times the blank thickness of the main body 1 of the framework.

[0039] A connecting plate 17 is further provided in the first U-shaped groove 11. The two ends of the connecting plate 17 are respectively fixedly connected to the inner side walls on both sides of the first U-shaped groove 11. The position of the connecting plate 17 corresponds to the connection part between the side beam 10 and the front cross beam 20. A positioning pin 18 is provided on the connecting plate 17. The positioning pin 18 sequentially penetrates through the connecting plate 17, the reinforcing plate 12 and the side beam 10 from top to bottom, and the two ends of the positioning pin 18 are respectively fixedly connected to the connecting plate 17 and the side beam 10. The connecting plate 17 can resist the inner side walls on both sides of the first U-shaped groove 11 to prevent it from deforming due to extrusion and collision, effectively improving the strength of the front side of the side beam 10. Together with the positioning pin 18, the connecting plate 17, the reinforcing plate 12 and the side beam 10 are further connected, and the stress received by the connecting plate 17 can be dispersed to the entire side beam 10 to ensure that the connecting plate 17 can play a stable role. In this embodiment, the connecting plate 17 is located above the front side of the reinforcing plate 12.

[0040] In the description of this specification, the descriptions referring to terms such as "one embodiment", "some embodiments", "examples", "specific examples", or "some examples", etc., mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0041] On the premise that there is no conflict, those skilled in the art can freely combine and superimpose the above additional technical features.

[0042] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Claims

1. An automotive rear floor skeleton, characterized in that, It includes a skeleton main body which is integrally formed by a front cross beam, a rear cross beam and two side beams. The skeleton main body is an axisymmetric structure, and the axis of symmetry is parallel to the vehicle body direction. The middle part of the side beam is concave to form a first U-shaped groove. The middle parts of the front cross beam and the rear cross beam are concave to form a second U-shaped groove and a third U-shaped groove respectively. The first U-shaped groove communicates with the second U-shaped groove and the third U-shaped groove respectively. A reinforcing plate is provided on the inner wall of the front side of the first U-shaped groove. A first splicing groove is provided on the side wall of the side beam far from the front cross beam. A protective plate adapted to it is provided at the first splicing groove. A second splicing groove is provided at the bent part where the side beam is connected to the front cross beam. An adapter plate adapted to it is provided at the second splicing groove. The adapter plate is located on the side wall of the second U-shaped groove close to the rear cross beam. The reinforcing plate, the protective plate and the adapter plate are all connected to the skeleton main body by using the hot stamping patch plate process. The skeleton main body is made of ultra-high strength steel.

2. The automotive rear floor skeleton according to claim 1, wherein The cross section of the reinforcing plate is in a U-shaped structure. The two side walls of the reinforcing plate are respectively connected to the two inner walls of the first U-shaped groove. The bottom wall of the reinforcing plate is connected to the inner wall of the bottom surface of the first U-shaped groove. A convex plate that bends towards the middle of the first U-shaped groove is provided on the side wall of the reinforcing plate far from the front cross beam. The convex plate is integrally formed with the reinforcing plate.

3. The automotive rear floor skeleton according to claim 2, characterized in that, A plurality of strengthening grooves with staggered distribution are provided on the bottom wall of the reinforcing plate. The lower end of the convex plate abuts against the bottom of the strengthening groove far from the front cross beam.

4. The automotive rear floor skeleton according to claim 2, characterized in that, Reinforcing ribs are also provided on the bottom wall of the reinforcing plate. The position of the reinforcing ribs corresponds to the downward bending part of the side beam.

5. The automotive rear floor skeleton according to claim 1, characterized in that, The thickness of the reinforcing plate is 1.5 to 2 times the blank thickness of the skeleton main body.

6. The automotive rear floor skeleton according to claim 1, wherein One end of the protective plate is connected to the inner side wall of the first U-shaped groove, and the other end of the protective plate is connected to the outer side wall of the first U-shaped groove.

7. The automotive rear floor skeleton according to claim 1, characterized in that, A first positioning groove is provided on the inner wall of the first U-shaped groove far from the front cross beam. A second positioning groove corresponding to the first positioning groove is provided on the protective plate. The second positioning groove is partially embedded in the first positioning groove and is adapted to it.

8. The automotive rear floor skeleton according to claim 1, characterized in that, The thickness of the protective plate and the adapter plate is 1.1 to 1.3 times the blank thickness of the skeleton main body.

9. The automotive rear floor skeleton according to claim 1, characterized in that, A connecting plate is also provided in the first U-shaped groove. The two ends of the connecting plate are respectively fixedly connected to the two inner walls of the first U-shaped groove. The position of the connecting plate corresponds to the connection part of the side beam and the front cross beam.

10. The automotive rear floor skeleton according to claim 9, characterized in that, A positioning pin is provided on the connecting plate. The positioning pin sequentially penetrates through the connecting plate, the reinforcing plate and the side beam from top to bottom. The two ends of the positioning pin are respectively fixedly connected to the connecting plate and the side beam.

Images