Vehicle skeleton structure and vehicle rear structure

Abstract

The present application relates to a vehicle frame structure and a vehicle rear structure. A vehicle frame structure (101) includes a first portion (101A) including one end (103), a second portion (101B) including the other end (104), an intermediate portion (101C), and a flange portion (120) having at least a first flange portion (121) continuously provided from the one end (103) to a flange boundary (125) provided halfway in a second region portion (132), and a second flange portion (122) continuously provided from the flange boundary (125) toward the other end (104) side, the second flange portion (122) protruding in an upward direction or a downward direction of the vehicle.

Description

Technical Field

[0001] This invention relates to a vehicle frame structure and a vehicle rear structure.

[0002] This application is based on and claims priority to Japanese Patent Application No. 2024-061573, filed in Japan on April 5, 2024, the contents of which are incorporated herein by reference. Background Technology

[0003] Conventionally, the straight section on the front side of a vehicle frame structure constructed at the front of a vehicle or the straight section on the rear side of a vehicle frame structure constructed at the rear of a vehicle has an energy-absorbing section that deforms due to the load input through the bumper during a collision from the front or rear, absorbing the collision energy (for example, Patent Document 1).

[0004] The vehicle frame structure in the front or rear structure of a vehicle is generally a closed-section structure. In Patent Document 1, the rear beam includes a straight section on the rear side, a straight section on the front side with a different tube axis position, and a bent section disposed between the straight sections on the rear and front sides. Patent Document 1 discloses a technique whereby by making the product of the material strength and plate thickness of the bent section greater than that of the straight section on the rear side, collision energy can be appropriately absorbed during a rear-end collision.

[0005] As a deformation method for ensuring energy absorption performance of the energy-absorbing section (hereinafter, sometimes referred to as the EA section), so-called corrugated deformation, which ensures a greater amount of plastic deformation throughout the entire EA section before the fracture of the material forming the EA section progresses, is preferred. Therefore, in Patent Document 1, a structure is also adopted to promote corrugated deformation by arranging a plurality of geometrically deformable sections 25 on the wall surface corresponding to the EA section in the vertical direction orthogonal to the load input direction.

[0006] Here, if the rigidity of the part of the straight section on the rear side that is adjacent to the downstream side of the EA section in the load input direction, that is, the part that is adjacent to the EA section on the front side, is different, then the deformation of this part will be different during a rear collision. As a result, the deformation mode of the EA section during a rear collision may be different.

[0007] However, in the construction of the straight section on the rear side of the rear beam in Patent Document 1, since no special study was conducted on the portion adjacent to the front side of the EA section, the rigidity of this portion is sometimes insufficient, and the preferred corrugated deformation cannot be obtained in the EA section during a rear-end collision. That is, when the EA section deforms due to a rear-end collision, the portion located on the front side of the vehicle than the EA section deforms more, and this deformation hinders the preferred deformation of the EA section.

[0008] Existing technical documents Patent documents Patent Document 1: Japanese Patent Publication No. 2022-547492 Summary of the Invention

[0009] The problem that the invention aims to solve The present invention was made in view of the above circumstances, and its object is to provide a vehicle frame structure and a vehicle rear structure that are less likely to be hindered when absorbing collision energy and can fully ensure energy absorption performance.

[0010] Methods for solving problems To address the aforementioned issues, the present invention employs the following configuration.

[0011] [1] A vehicle frame structure is a hollow tubular vehicle frame structure that can be disposed at the front or rear of a vehicle and has one end and another end separated along the length direction. The vehicle frame structure comprises: a first portion that can be disposed at a position near the front of the vehicle or a position near the rear of the vehicle, and includes the one end; a second portion that can be disposed at a position near the center of the vehicle, with the tube axis located at a position different from the tube axis position of the first portion, and includes the other end; a middle portion disposed between the first portion and the second portion, connecting the first portion and the second portion; and a flange portion provided along the length direction of the vehicle frame structure. The flange portion protrudes in a direction different from the length direction and includes: a first region including one end; and a second region located at a position adjacent to the other end of the vehicle frame structure, closer to the first region, and having an axial yield strength greater than that of the first region. The flange portion includes at least: a first flange portion continuously disposed from one end of the vehicle frame structure to a flange boundary disposed in the middle of the second region portion; and a second flange portion continuously disposed from the flange boundary toward the other end of the vehicle frame structure, the second flange portion protruding in an upward or downward direction of the vehicle.

[0012] [2] According to the vehicle frame structure described in [1], the first flange portion and the second flange portion protrude from different positions in the circumferential direction orthogonal to the length direction of the hollow tubular vehicle frame structure in different directions.

[0013] [3] According to the vehicle frame structure described in [1] or [2], the first region is an energy absorption portion that absorbs load energy by deforming under axial compressive load in the tube axis direction.

[0014] [4] A vehicle frame structure according to any one of [1] to [3], wherein the wall thickness of the vehicle frame structure in the first region is less than the wall thickness of the vehicle frame structure in the second region.

[0015] [5] A vehicle frame structure according to any one of [1] to [3], wherein the tensile strength and wall thickness of the vehicle frame structure in the first region are less than the tensile strength and wall thickness of the vehicle frame structure in the second region.

[0016] [6] The vehicle frame structure according to any one of [1] to [3], wherein, for each of the first region and the second region, when the difference (Hm-Hs) between the hardness Hm at the center of the wall thickness direction in the cross section perpendicular to the tube axis direction of the first part and the hardness Hs at the surface of the wall thickness direction in the cross section is set as the hardness difference, the hardness difference in the first region is greater than the hardness difference in the second region.

[0017] [7] A vehicle frame structure according to any one of [1] to [6], wherein an opening is formed on the vehicle frame structure for connecting a hollow cylindrical crossbeam along the left-right direction of the vehicle, the opening being located at a position closer to the other end than the flange boundary.

[0018] [8] According to [7], the vehicle frame structure, wherein the opening is located in the first part of the vehicle frame structure.

[0019] [9] A rear structure for a vehicle, comprising a vehicle frame structure as described in any one of [1] to [8].

[0020]

[10] A rear structure for a vehicle includes: a pair of hollow tubular vehicle frame structures arranged along the front-rear direction of the vehicle; and a hollow tubular crossbeam arranged along the left-right direction of the vehicle, and connecting the pair of vehicle frame structures, wherein the pair of vehicle frame structures are any one of [1] to [8].

[0021] Invention Effects According to the present invention, a vehicle frame structure and a vehicle rear structure are provided that are less hindered by the preferred corrugated deformation when absorbing collision energy and can sufficiently ensure the energy absorption performance as envisioned. Attached Figure Description

[0022] Figure 1 This is a perspective view of a rear structure for a vehicle according to an embodiment of the present invention.

[0023] Figure 2 This is a top view schematic diagram illustrating a rear structure for a vehicle according to an embodiment of the present invention.

[0024] Figure 3 This is a diagram illustrating a rear structure for a vehicle according to an embodiment of the present invention, and is related to... Figure 2 A schematic diagram of the cross section corresponding to line AA.

[0025] Figure 4 This is a diagram illustrating a rear structure for a vehicle according to an embodiment of the present invention, and is related to... Figure 2 A schematic diagram of the cross section corresponding to the BB line.

[0026] Figure 5 This is a diagram illustrating a rear structure for a vehicle according to an embodiment of the present invention, and is related to... Figure 2 A schematic diagram of the cross-section corresponding to the CC line.

[0027] Figure 6 This is a top view schematic diagram illustrating the vehicle frame structure of the rear structure of a vehicle according to an embodiment of the present invention.

[0028] Figure 7A This is a diagram showing the vehicle frame structure provided in the rear structure of a vehicle according to an embodiment of the present invention, and it shows... Figure 1 as well as Figure 2 An enlarged top view of the main parts.

[0029] Figure 7B It is along Figure 7A A schematic diagram of the cross-section of the DD line.

[0030] Figure 8A This is a diagram illustrating the vehicle frame structure provided with a vehicle rear structure according to an embodiment of the present invention, and is along... Figure 7A A schematic diagram of the cross-section of the GG line.

[0031] Figure 8B It is along Figure 8A A schematic diagram of the cross-section of the EE line.

[0032] Figure 9 This is an enlarged side view schematic diagram showing the main part of a modified example of the rear structure for a vehicle.

[0033] Figure 10 This is a graph showing the test results of the rear structure for a vehicle in the embodiment and the rear structure for a vehicle in the comparative example. Detailed Implementation

[0034] Hereinafter, the vehicle frame structure and the vehicle rear structure according to embodiments of the present invention will be described.

[0035] (First Implementation) First, the rear structure 100 for a vehicle according to the first embodiment of the present invention will be described. Figure 1 3D diagram and Figure 2 The vehicle rear structure 100 of this embodiment, shown in the top view, is configured to include: a pair of hollow tubular vehicle frame structures 101 arranged along the longitudinal direction of the vehicle; and a hollow tubular crossbeam 102 arranged along the left-right direction of the vehicle and connecting the pair of vehicle frame structures 101. Furthermore, in Figure 1 and Figure 2 In the rear structure 100 of the vehicle shown, such as Figure 2 As shown by the single-dotted line, it may also have a bumper beam 110 that engages with one end 103 of a pair of vehicle frame structures 101. Furthermore, as can be understood from the configuration of the bumper beam 110, in Figure 1 and Figure 2 In the rear structure 100 of the vehicle shown, one end 103 of a pair of vehicle frame structures 101 becomes the rear side of the vehicle, and the other end 104 of the pair of vehicle frame structures 101 becomes the central side of the vehicle.

[0036] Figures 3-5 express Figure 2 A schematic diagram of the cross-sections of lines AA, BB, and CC. (See attached diagram.) Figures 3-5 As shown, both the vehicle frame structure 101 and the crossbeam 102 are hollow tubular components with a closed cross-section. However, at the connection between the vehicle frame structure 101 and the crossbeam 102, the hollow portion of the vehicle frame structure 101 is interconnected with the hollow portion of the crossbeam 102. Along with this, an opening is provided in the vehicle frame structure 101 at the connection point with the crossbeam 102. The opening will be described later.

[0037] In addition, such as Figures 3-5 As shown, the rear structure 100 for a vehicle in this embodiment is constructed by integrally joining an upper part 100A located on the upper side of the vehicle and a lower part 100B located on the lower side of the vehicle. The upper part 100A and the lower part 100B are formed, for example, by a so-called hot pressing method after steel plates are machined into a predetermined shape to become blanks. As shown from... Figure 2As can be seen from the cross-sections at lines AA, BB, and CC, each part of the upper component 100A and the lower component 100B has a cross-sectional shape formed by web portions 100a and 100b, longitudinal wall portions 100c, and flange portions 100d, respectively. The rear structure 100 for a vehicle in this embodiment is integrated by joining the flange portions 100d of the upper component 100A and the lower component 100B together. Furthermore, as a joining method, spot welding can be used, for example, and a structural adhesive can also be used in conjunction with spot welding.

[0038] And, as Figures 3-5 As shown, the upper component 100A includes an upper side beam 101U and an upper side crossbeam 102U. When the upper component 100A and the lower component 100B are integrally joined, the upper side beam 101U constitutes the vehicle frame structure 101 of the rear structure 100 for a vehicle. Furthermore, the upper side crossbeam 102U constitutes the crossbeam 102 of the rear structure 100 for a vehicle.

[0039] Similarly, the lower component 100B includes a lower side beam 101D and a lower side crossbeam 102D. The lower side beam 101D, together with the upper side beam 101U, constitutes the vehicle frame structure 101 of the rear structure 100 for a vehicle. The lower side crossbeam 102D, together with the upper side crossbeam 102U, constitutes the crossbeam 102 of the rear structure 100 for a vehicle.

[0040] Then, the upper side beam 101U and upper side crossbeam 102U constituting the upper part 100A are integrally formed by hot pressing. Similarly, the lower side beam 101D and lower side crossbeam 102D constituting the lower part 100B are integrally formed by hot pressing. Hot pressing refers to the method of heating a steel plate as a blank to soften it, forming the heated blank using a forming mold, and using the mold to dissipate heat and process the blank into the desired shape. The heating temperature of the blank can be above Ac3 point. Ac3 point refers to the temperature at which ferrite disappears in the metal structure of the blank. The metal structure processed by hot pressing becomes a structure mainly composed of martensite.

[0041] Alternatively, the upper component 100A and the lower component 100B can also be formed by hot pressing a so-called welded blank. The welded blank is formed by welding together multiple steel plates with different tensile strengths and thicknesses. The upper component 100A and the lower component 100B formed from such welded blanks have locally different tensile strengths or plate thicknesses. For example, as described later, the upper side beam 101U and the lower side beam 101D can each be composed of multiple regions (the first region and the second region, described later) with different tensile strengths or plate thicknesses.

[0042] In addition, when forming welded blanks by hot pressing, heating the welded blanks to above point Ac3 can eliminate the heat-affected zone of the welded part that remains during the manufacturing of the welded blanks.

[0043] In this embodiment, the rear vehicle structure 100 has upper wall portions 101a and 102a facing upwards towards the vehicle and lower wall portions 101b and 102b facing downwards towards the vehicle, respectively, on a pair of vehicle frame structures 101 and crossbeam 102. Furthermore, in this embodiment, it is preferable that the upper wall portions 101a and 102a have the same height at the connection point between the vehicle frame structure 101 and the crossbeam 102, and that the lower wall portions 101b and 102b have the same height. Additionally, to further improve energy absorption performance, the upper wall portions 101a and 102a can be made to have different heights by forming ridges at the connection point between the vehicle frame structure 101 and the crossbeam 102, and the lower wall portions 101b and 102b can also have different heights.

[0044] Next, a pair of vehicle frame structures 101, which are part of the vehicle rear structure 100 of this embodiment, will be described in detail. Figure 6 The diagram shows a top view of the vehicle frame structure 101 according to this embodiment. Additionally, Figure 7A The diagram shows a schematic top view of a portion of the upper surface of the vehicle frame structure 101. Figure 7B The middle shows Figure 7A A schematic diagram of the longitudinal section at the DD line. Furthermore, Figure 8A The diagram shows a schematic cross-sectional view of a portion of the vehicle frame structure 101. Figure 8B The middle shows Figure 8A A longitudinal section diagram at the EE line. Furthermore, although the vehicle frame structure 101 of this embodiment is as shown in... Figures 1 to 5 As described above, it can be configured at the rear of the vehicle. However, the configuration position of the vehicle frame structure 101 in this embodiment is not limited to the rear of the vehicle, but can also be configured at the front of the vehicle.

[0045] like Figure 6As shown, the vehicle frame structure 101 of this embodiment is a hollow tubular component having one end 103 and the other end 104 separated along the length direction. It includes: a first portion 101A including one end 103 of the vehicle frame structure 101; a second portion 101B including the other end 104 of the vehicle frame structure 101; an intermediate portion 101C disposed between the first portion 101A and the second portion 101B; and a flange portion 120. The flange portion 120 is provided along the length direction of the vehicle frame structure 101 and protrudes in a direction different from the length direction of the vehicle frame structure 101.

[0046] The first part 101A, the second part 101B, and the middle part 101C are all hollow tubular, and their hollow parts are interconnected.

[0047] Furthermore, the first part 101A, the second part 101B, and the middle part 101C constituting the vehicle frame structure 101 each have an upper wall portion 101a disposed on the upper side of the vehicle, a lower wall portion 101b disposed on the lower side of the vehicle, and a side wall portion 101c connecting the upper wall portion 101a and the lower wall portion 101b. Additionally, as... Figures 3-5 As shown, the upper wall portion 101a and the lower wall portion 101b correspond to the web portions 100a and 100b in the upper component 100A and the lower component 100B, respectively. In addition, the side wall portion 101c corresponds to the longitudinal wall portion 100c in the upper component 100A and the lower component 100B.

[0048] And, as Figures 3-5 As shown, the flange portion 120 is formed by the flange portions 100d of the upper component 100A and the lower component 100B joining each other.

[0049] In this embodiment, the vehicle frame structure 101 absorbs collision energy by corrugating a portion of the first portion 101A, specifically the portion near one end 103 of the first portion 101A, when external stress is input due to a collision, without deforming the second portion 101B and the intermediate portion 101C. More specifically, the region of the first portion 101A near one end 103 of the vehicle frame structure 101 (the first region described later) is corrugated to absorb collision energy, while the region of the first portion 101A near the other end 104 of the vehicle frame structure 101 (the second region described later) remains undeformed. Thus, the intermediate portion 101C, located at the predetermined connection position between the vehicle frame structure 101 and the crossbeam 102, and positioned closer to the vehicle center than the first portion 101A, will not deform due to a collision. Hereinafter, the first portion 101A, the second portion 101B, the intermediate portion 101C, and the flange portion 120 will be described.

[0050] The first part 101A is configured to be positioned at the front of the vehicle or at the rear of the vehicle, and includes one end 103 of the vehicle frame structure 101. When the bumper beam 110 is mounted on the vehicle frame structure 101, it is mounted on this first part 101A. The tube axis of the first part 101A is generally straight.

[0051] The first part 101A can connect to the crossbeam 102. The vehicle frame structure 101 of this embodiment has a generally closed cross-section structure, but when the crossbeam 102 is connected to the vehicle frame structure 101, such as... Figure 8A As shown, an opening 150 is provided on the side wall portion 101c of the vehicle frame structure 101 at its connection position. It is configured such that the hollow portion of the vehicle frame structure 101 and the hollow portion of the crossbeam 102 are connected via the opening 150.

[0052] The second part 101B is configured to be positioned near the center of the vehicle, with its tube axis located at a different position than that of the first part 101A. Furthermore, the second part 101B includes the other end 104 of the vehicle frame structure 101. The other end 104 of the vehicle frame structure 101 can engage with other structures constituting the vehicle's cab.

[0053] The intermediate portion 101C is positioned between the first portion 101A and the second portion 101B to connect them. If the intermediate portion 101C were omitted and the first portion 101A and the second portion 101B were arranged in a straight line, the first portion 101A might interfere with the vehicle's tire covers (for the front or rear wheels), engine, battery, axle, etc. Therefore, the intermediate portion 101C serves to position the axle of the first portion 101A differently from that of the second portion 101B.

[0054] In addition, such as Figure 6 and Figure 7A As shown, the first portion 101A is divided into a first region 131 and a second region 132 located at one end 103 of the vehicle frame structure 101. The second region 132 is located at the other end 104 of the first region 131 and is adjacent to the first region 131, and has an axial yield strength greater than that of the first region 131. Additionally, the vehicle frame structure 101 has a third region 133 located at the other end 104 of the vehicle frame structure 101, closer to the second region 132. The third region 133 includes a middle portion 101C and a second portion 101B. Figure 6 , Figure 7A and Figure 8A As shown, the first region 131 occupies the area of ​​the first part 101A that includes one end 103 of the vehicle frame structure 101. In addition, the second region 132 is adjacent to the first region 131 and also adjacent to the middle part 101C, and occupies the area including the crossbeam 102 forming a predetermined position.

[0055] The first region 131, the second region 132, and the third region 133 are joined together, for example, by welding. For example, the first region 131, the second region 132, and the third region 133 are provided by manufacturing the upper part 100A and the lower part 100B using welded blanks as raw materials, as described above.

[0056] When the first region 131 and the second region 132 are provided in the first part 101A, the wall thickness of the upper wall 101a, lower wall 101b, and side wall 101c constituting the first region 132 can be smaller than the wall thickness of each part in the second region 131. This results in the second region 132 having a greater axial yield strength than the first region 131. Therefore, when impact energy is input to the first part 101A, the second region 132 does not deform, while the first region 131 preferentially deforms in a corrugated manner. In this way, the first region 131 functions as an energy-absorbing portion that deforms due to axial compressive load in the tube axis direction to absorb load energy. Furthermore, the wall thickness of the first region 131 is constant and does not vary locally. Similarly, the wall thickness of the second region 132 is constant and does not vary locally.

[0057] Furthermore, when the first region 131 and the second region 132 are provided in the first part 101A, the tensile strength and wall thickness of the upper wall 101a, lower wall 101b, and side wall 101c constituting the first region 132 can be smaller than the tensile strength and wall thickness of each part of the second region 131. This results in the axial yield strength of the second region 132 being greater than that of the first region 131. Therefore, when impact energy is input to the first part 101A, the second region 132 does not deform, while the first region 131 preferentially deforms in a corrugated manner. Additionally, the tensile strength and wall thickness of the first region 131 remain constant and do not vary locally. Similarly, the tensile strength and wall thickness of the second region 132 remain constant and do not vary locally.

[0058] Furthermore, when the first region 131 and the second region 132 are provided in the first part 101A, it is preferable to adjust the hardness difference in the wall thickness direction of the upper wall 101a, the lower wall 101b, and the side wall 101c. Specifically, the hardness difference of the first region 131 can be made greater than the hardness difference of the second region 132. In addition, the hardness difference of the first region 131 is constant and does not vary locally. Similarly, the hardness difference of the second region 132 is constant and does not vary locally.

[0059] The hardness difference refers to the difference (Hm-Hs) between the hardness Hm at the center of the wall thickness direction in a cross-section perpendicular to the tube axis of the first part 101A in the upper wall portion 101a, lower wall portion 101b, and side wall portion 101c, and the hardness Hs at the surface layer in the wall thickness direction of that cross-section. Furthermore, the term "surface layer in the wall thickness direction" refers to the region extending from the surface to a depth of (1 / 8)t, assuming a wall thickness of t for the upper wall portion 101a, lower wall portion 101b, and side wall portion 101c. Hardnesses Hs and Hm can be Vickers hardness measured under the same conditions.

[0060] By making the hardness difference of the first region 131 greater than that of the second region 132, when the first region 131 deforms due to the input of collision energy to the first part 101A, the surface of the upper wall 101a, lower wall 101b and side wall 101c of the first region 131 undergoes plastic deformation and is less prone to cracking. As a result, the first part 101A will not break, and the energy absorption capacity of the vehicle frame structure 101 can be maintained until the collision energy is dissipated.

[0061] The wall thickness, tensile strength, and hardness difference of the third region 133 are not particularly limited; for example, they can be the same as those of the first region 131. Furthermore, the wall thickness, tensile strength, and hardness difference of the third region 133 are kept constant and do not vary locally.

[0062] Furthermore, the welded portion that joins the first region 131, the second region 132, and the third region 133 preferably does not have a heat-affected zone. As described above, when manufacturing the upper component 100A and the lower component 100B from the welded blank using a hot pressing method, the temperature is raised to point Ac3 or higher, thereby eliminating the heat-affected zone in the welded portion that joins the first region 131, the second region 132, and the third region 133.

[0063] Next, the flange portion 120 will be described. For example... Figure 2 , Figure 6 and Figure 7AAs shown, the vehicle frame structure 101 of this embodiment includes a flange portion 120. The flange portion 120 of the vehicle frame structure 101 includes a first flange portion 121, a second flange portion 122, a third flange portion 123, and a fourth flange portion 124. The upper component 100A and the lower component 100B constituting the vehicle frame structure 101 are joined at these first flange portions 121, second flange portions 122, third flange portions 123, and fourth flange portions 124, thereby constituting a hollow tubular vehicle frame structure 101 as described above.

[0064] The first flange portion 121 is located in a part of the first portion 101A of the vehicle frame structure 101 and protrudes toward one side of the vehicle frame structure 101 (outer side in the width direction of the vehicle). The protruding direction of the first flange portion 121 is substantially constant along the length direction of the first flange portion 121. More specifically, the first flange portion 121 is located at one end 103 of the vehicle frame structure 101 in the first portion 101A of the vehicle frame structure 101. As described above, the first portion 101A is composed of a first region portion 131 including one end 103 and a second region portion 132, and the first flange portion 121 continues from one end 103 of the first region portion 131 to a midpoint of the second region portion 132. In this embodiment, the position where the first flange portion 121 is interrupted midway through the second region portion 132 is referred to as the flange boundary 125. The first flange portion 121 extends from one end 103 to the flange boundary 125 in the middle of the second region portion 132, without interruption at the boundary between the first region portion 131 and the second region portion 132.

[0065] The portion 121A protruding from the first region 131 in the first flange 121 is formed from the same raw material constituting the first region 131. Similarly, the portion 121B protruding from the second region 132 is formed from the same raw material constituting the second region 132. That is, the first flange 121 is formed from one or more different raw materials in terms of plate thickness, hardness, and hardness difference. Furthermore, the portion 121A protruding from the first region 131 and the portion 121B protruding from the second region 132 are joined by welding.

[0066] The flange boundary 125 can be located anywhere along the length of the second region 132. More preferably, the flange boundary 125 is located at a position further to the other end 104 than the boundary between the first region 131 and the second region 132, and at a position further to the other end 103 than the sidewall portion of the crossbeam 102. However, the flange boundary 125 does not overlap with the boundaries of the first region 131 and the second region 132. Figure 7A and Figure 8A In the accompanying drawings, a double-headed arrow, designated F, indicates the range within which the flange boundary 125 can be configured. That is, the position of the flange boundary 125 is not limited to... Figure 7A The position shown can be anywhere within the range indicated by reference numeral F. The flange boundary 125 is located on the other end 104 side, beyond the boundary between the first region 131 and the second region 132, thus preventing damage to the first portion 101A at the boundary between the first region 131 and the second region 132 upon input of collision energy. Furthermore, the flange boundary 125 is located on one end 103 side, beyond the position of the sidewall portion of the crossbeam 102, thereby limiting the deformation range during collision and reducing the likelihood of deformation affecting the middle portion 101C and the crossbeam 102.

[0067] The second flange portion 122 is located in the first portion 101A, specifically in the part where the first flange portion 121 is not formed, the intermediate portion 101C, and the second portion 101B. Furthermore, the second flange portion 122 protrudes towards the upper side (upper side of the vehicle) of the vehicle frame structure 101. The protrusion direction of the second flange portion 122 relative to the vehicle frame structure 101 is substantially constant along the length direction of the second flange portion 122. More specifically, the second flange portion 122 extends from the middle of the first portion 101A of the vehicle frame structure 101, in other words, from the flange boundary 125 of the second region portion 132 towards the other end 104, and extends to the other end 104 via the intermediate portion 101C and the second portion 101B. In this embodiment, the second flange portion 122 is continuously and uninterruptedly connected at the boundary between the second region portion 132 of the first portion 101A and the intermediate portion 101C, and at the boundary between the intermediate portion 101C and the second portion 101B. However, it is not limited to this arrangement, and the second flange portion 122 may also be interrupted midway. Furthermore, the second flange portion 122 may also protrude toward the lower side (lower side of the vehicle) of the vehicle frame structure 101.

[0068] The first flange portion 121 and the second flange portion 122 protrude from different positions in the circumferential direction orthogonal to the length direction of the hollow tubular vehicle frame structure 101. That is, as Figure 4 As shown, the first flange portion 121 protrudes from the side wall portion 101c of the vehicle frame structure 101. On the other hand, as... Figure 3 As shown, the second flange portion 122 protrudes from the connection between the upper wall portion 101a and the side wall portion 101c of the vehicle frame structure 101, and protrudes in a direction different from that of the first flange portion 121.

[0069] The third flange portion 123 and the fourth flange portion 124 are located opposite to the first flange portion 121 in the tube axis direction of the vehicle frame structure 101. The third flange portion 123 is located on the side closer to one end 103 of the crossbeam 102 and protrudes toward the other side of the vehicle frame structure 101 (inside the vehicle's width direction). The fourth flange portion 124 is located on the side closer to the other end 104 of the crossbeam 102 and protrudes toward the other side of the vehicle frame structure 101 (inside the vehicle's width direction). Furthermore, the third flange portion 123 and the fourth flange portion 124 are connected to the flange portion 100d of the crossbeam 102.

[0070] According to the vehicle frame structure 101 of this embodiment, the axial yield strength of the first region 131 is smaller than that of the second region 132. Therefore, when impact energy is input along the tube axis direction of the first portion 101A, buckling deformation occurs in the first region 131. Preferably, the first region 131 is corrugated to absorb the impact energy. Here, as described above, the first flange portion 121 extends uninterruptedly from one end 103 to the flange boundary 125 at the boundary between the first region 131 and the second region 132, that is, at the boundary where the properties of the raw material change. Therefore, when impact energy is input along the tube axis direction of the first portion 101A, the boundary between the first region 131 and the second region 132 will not break, and the first region 131 can be corrugated to fully absorb the impact energy. In addition, the boundary (flange boundary 125) between the first flange portion 121 and the second flange portion 122 is located at one end 103, which is closer to the side wall portion of the crossbeam 102 than the side wall portion of the crossbeam 102. This reduces the possibility that the deformation during the collision will affect the middle portion 101C and the crossbeam 102.

[0071] Therefore, according to this embodiment, a vehicle frame structure 101 and a vehicle rear structure 100 can be provided that are preferably corrugated and whose deformation is not easily hindered when absorbing collision energy and can fully ensure energy absorption performance.

[0072] In addition, the second flange portion 122 is continuously provided between the flange boundary 125 and the other end 104, thereby improving the rigidity of the intermediate portion 101C and the second portion 101B.

[0073] Furthermore, when the vehicle frame structure 101 of this embodiment is applied to a vehicle, sometimes parts such as wheel covers are joined to the middle portion 101C. However, the second flange portion 122 of the vehicle frame structure 101 protrudes in the upward direction of the vehicle. The second flange portion 122 protrudes in a direction different from the protrusion direction of the first flange portion 121. Therefore, the second flange portion 122 will not interfere when the wheel cover is installed on the vehicle frame structure 101.

[0074] In addition, in the vehicle frame structure 101 of this embodiment, an opening 150 for connecting the crossbeam 102 may be formed. In this case, the opening 150 is formed at the other end 104 side, which is closer to the flange boundary 125. Therefore, even if there is a concern that the rigidity of the vehicle frame structure 101 may be reduced due to the presence of the opening 150, the amount of collision energy absorbed by the first flange 121 can be maximized, thereby suppressing deformation at the predetermined connection position with the crossbeam 102.

[0075] Furthermore, in the vehicle frame structure 101 of this embodiment, the wall thickness of the vehicle frame structure 101 at the first region 131 is smaller than the wall thickness of the vehicle frame structure 101 at the second region 132. Therefore, during a collision, the second region 132 is difficult to deform while the first region 131 is easy to deform, and the first region 131 can absorb the collision energy.

[0076] Furthermore, in the vehicle frame structure 101 of this embodiment, the tensile strength and wall thickness of the vehicle frame structure 101 in the first region 131 are smaller than those of the vehicle frame structure 101 in the second region 132. Therefore, in the event of a collision, the second region 132 is difficult to deform while the first region 131 is easy to deform, and the first region 131 can absorb the collision energy.

[0077] Furthermore, in the vehicle frame structure 101 of this embodiment, the hardness difference of the first region 131 is greater than that of the second region 132. Therefore, during a collision, the surface of the upper wall 101a, lower wall 101b and side wall 101c constituting the first region 131 is less likely to crack, and the collision energy can be fully absorbed in the first region 131, thus suppressing the deformation from reaching the second region 132.

[0078] The rear structure 100 for a vehicle in this embodiment includes a pair of vehicle frame structures 101. The vehicle frame structure 101 is provided with a first flange portion 121. When collision energy is input along the tube axis direction of the first portion 101A, buckling deformation occurs in the first region portion 131, and damage at the boundary between the first region portion 131 and the second region portion 132 is prevented. Therefore, the amount of collision energy absorbed can be maximized, and the propagation of deformation towards the center of the vehicle can be suppressed.

[0079] Furthermore, the rear structure 100 for vehicles in this embodiment includes a pair of vehicle frame structures 101 and a crossbeam 102. The vehicle frame structure 101 is the vehicle frame structure 101 of this embodiment with a first flange portion 121. When collision energy is input along the tube axis direction of the first portion 101A, buckling deformation occurs in the first region portion 131, and damage at the boundary between the first region portion 131 and the second region portion 132 is prevented. As a result, the connection portion between the vehicle frame structure 101 and the crossbeam 102 does not deform during a collision, thus reducing the range of deformation and suppressing the propagation of deformation toward the center of the vehicle.

[0080] The embodiments of the present invention have been described above, but the present invention is not limited to the above-described manner and modifications can be made without departing from the scope of the present invention. For example, in the above embodiments, it was described that the upper part 100A and the lower part 100B are manufactured using a welding blank as raw material, and the first region 131, the second region 132, and the third region 133 are provided. However, the first region 131 and the second region 132 are not limited to being joined in advance at the welding blank stage, and the first region 131 may also be joined later by welding or the like.

[0081] exist Figure 9 The image shows an enlarged cross-sectional view of the first part. (See image for details.) Figure 9 As shown, the first region 131 can also be joined by lap welding. The lap portion K created by lap welding is included in the second region 132.

[0082] Furthermore, in this embodiment, each of the pair of vehicle frame structures 101 in the vehicle rear structure 100 has an opening 150. However, the opening is not necessary in the pair of vehicle frame structures 101 and can be omitted. If no opening is provided in the pair of vehicle frame structures 101, the rear structure of the vehicle can be constructed by welding the flange at the end of the crossbeam 102 to the pair of vehicle frame structures.

[0083] Example The upper and lower components are manufactured by hot pressing the welded blanks, and then spot welding is used to join the upper and lower components together, thereby producing a finished product. Figure 1 and Figure 2The illustrated embodiment is a rear structure for a vehicle. A bumper beam is attached to one end of the vehicle frame structure. The vehicle frame structure constituting the rear structure includes a first region, a second region, and a third region. Additionally, as a flange portion, it has a first flange portion continuously extending from one end of the vehicle frame structure to a flange boundary located midway through the second region, and a second flange portion continuously extending from the flange boundary to the other end of the vehicle frame structure. The first region portion is made of steel with a plate thickness of 1.0 mm and a tensile strength of 1000 MPa. The second region portion is made of steel with a plate thickness of 1.4 mm and a tensile strength of 2000 MPa.

[0084] Furthermore, as a comparative example, except that a first flange portion is formed that extends from one end of the vehicle frame structure to the boundary between the first region portion and the second region portion, and a second flange portion extends from the boundary between the first region portion and the second region portion to the other end of the vehicle frame structure, the comparative example vehicle rear structure is manufactured in the same manner as the embodiment.

[0085] CAE analysis was performed on the bumper beam of the rear structure of the vehicle in the embodiments and comparative examples, under the following test specifications. Then, the time-dependent change in the reaction force applied to the barrier was measured. The results are shown below. Figure 10 .exist Figure 10 In this context, "offset construction" is an example, and "consistent construction" is a comparative example.

[0086] <Test Specifications> • Regulatory testing: in accordance with US FMVSS 301 • Barrier type: Deformable aluminum honeycomb barrier Collision speed: 80 km / h • Barrier weight: 1360Kg • Overlap rate: 70% • Steel grade: Hot-pressed steel with tensile strength of 1GPa~2GPa • Steel constituting the first region: 1GPa grade hot-pressed steel plate, thickness t1.0mm • Steel constituting the second and third zones: 2GPa grade hot-pressed steel plate, thickness t1.4mm • Steel material constituting the crossbeam: 1.5GPa grade hot-pressed steel plate, thickness t1.0mm like Figure 10As shown, the reaction force of the rear structure for a vehicle in the embodiment did not decrease after 0.01 seconds compared to the rear structure for a vehicle in the comparative example. In the rear structure for a vehicle in the embodiment, the first region can undergo corrugated deformation to sufficiently absorb impact energy. On the other hand, in the rear structure for a vehicle in the comparative example, damage occurs at the boundary between the first and second regions, and the absorption of impact energy is insufficient. This difference can be considered to occur... Figure 10 The curve in the graph.

[0087] Industrial availability The present invention provides a vehicle frame structure and a vehicle rear structure that are less hindered by the preferred corrugated deformation when absorbing collision energy and can fully ensure the energy absorption performance as envisioned, and therefore has industrial applicability.

[0088] Explanation of symbols 100: Rear structure for vehicles 100A: Upper component 100B: Lower component 101: Vehicle Frame Structure 101a: Upper wall portion 101b: Lower wall portion 101c: Side wall portion 101A: Part One 101B: Part Two 101C: Middle section 101U: Upper side beam 101D: Lower side beam 102: Crossbeam 102U: Upper crossbeam 102D: Lower crossbeam 103: One end of the vehicle's frame structure 104: The other end of the vehicle's frame structure 110: Bumper beam 120: Flange portion 121: First flange portion 122: Second flange portion 125: Flange boundary 131: First Regional Division 132: Second Regional Division 133: Third Regional Department 150: Opening

Claims

1. A vehicle frame structure, which is a hollow tubular vehicle frame structure that can be disposed at the front or rear of a vehicle and has one end and another separated along its length, the vehicle frame structure comprising: The first part can be configured at a position near the front of the front of the vehicle or at a position near the rear of the rear, and includes one end; The second part can be configured at a position near the center of the vehicle, the tube shaft position is located at a position different from the tube shaft position of the first part, and includes the other end; The middle part is positioned between the first part and the second part, connecting the first part and the second part; as well as The flange portion is provided along the length direction of the vehicle frame structure and protrudes in a direction different from the length direction. The first part includes: The first region includes the said one end; and The second region is located at the other end of the vehicle frame structure, adjacent to the first region, and has an axial yield strength greater than that of the first region. The flange portion has at least: The first flange portion extends continuously from one end of the vehicle frame structure to the flange boundary located midway through the second region portion; and The second flange portion is continuously provided from the flange boundary toward the other end of the vehicle frame structure. The second flange protrudes upward or downward toward the vehicle.

2. The vehicle frame structure according to claim 1, wherein, The first flange and the second flange protrude from different positions in the circumferential direction orthogonal to the length direction of the hollow tubular vehicle frame structure, respectively, in different directions.

3. The vehicle frame structure according to claim 1, wherein, The first region is an energy absorption section that absorbs load energy by deforming under axial compressive load in the direction of the tube axis.

4. The vehicle frame structure according to claim 1, wherein, The wall thickness of the vehicle frame structure in the first region is less than the wall thickness of the vehicle frame structure in the second region.

5. The vehicle frame structure according to claim 1, wherein, The tensile strength and wall thickness of the vehicle frame structure in the first region are less than those of the vehicle frame structure in the second region.

6. The vehicle frame structure according to claim 1, wherein, For each of the first region and the second region, when the difference (Hm-Hs) between the hardness Hm at the center of the wall thickness direction in the cross section perpendicular to the tube axis direction of the first part and the hardness Hs at the surface of the wall thickness direction in the cross section is defined as the hardness difference, the hardness difference in the first region is greater than the hardness difference in the second region.

7. The vehicle frame structure according to claim 1, wherein, An opening is formed on the vehicle frame structure for connecting a hollow cylindrical crossbeam along the left-right direction of the vehicle. The opening is located at a position closer to the other end than the flange boundary.

8. The vehicle frame structure according to claim 7, wherein, The opening is located in the first part of the vehicle frame structure.

9. A rear structure for a vehicle, comprising the vehicle frame structure according to any one of claims 1 to 8.

10. A rear structure for a vehicle, comprising: A pair of hollow tubular vehicle frame structures, arranged along the longitudinal direction of the vehicle; and Hollow tubular crossbeams are arranged along the left-right direction of the vehicle and connect the pair of vehicles with a frame structure. The pair of vehicle frame structures are the vehicle frame structures according to any one of claims 1 to 8.

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