Frame member for vehicle and vehicle body front structure

Abstract

Provided are a vehicle frame member and a vehicle body front structure capable of improving the amount of absorbed collision load. The vehicle frame member includes: a first vertical wall; a second longitudinal wall; a first cross wall; a second cross wall; a first inner wall disposed between the first vertical wall and the second vertical wall in the vehicle width direction and extending in the vertical direction in a cross section so as to connect the first transverse wall and the second transverse wall to each other; and a second inner wall disposed between the second vertical wall and the first inner wall in the vehicle width direction and extending in the vertical direction in a cross section so as to connect the first transverse wall and the second transverse wall to each other. Each of the first transverse wall and the second transverse wall includes a first portion connecting the first vertical wall and the first inner wall, a second portion connecting the first inner wall and the second inner wall, and a third portion connecting the second vertical wall and the second inner wall. A bending stiffness of the first portion and a bending stiffness of the third portion are greater than a bending stiffness of the second portion.

Description

Technical Field

[0001] This invention relates to a frame component for a vehicle and a front body structure. Background Technology

[0002] Patent Document 1 discloses a front portion of a car comprising a frame component and an energy-absorbing box, which serves as an impact-absorbing component, fastened to the front of the frame component. Furthermore, Patent Document 1 describes how, when an impact is applied to the front portion of the car due to a collision or the like, the energy-absorbing box buffers the impact transmitted to the car body by repeatedly bending and deforming along its extension direction.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2002-188673

[0006] The technical problem that the invention aims to solve

[0007] In Patent Document 1, if the energy-absorbing box inadvertently deforms when an impact is applied to the front part of a car due to a collision, the collision load is not efficiently transferred from the energy-absorbing box to the frame component, and the amount of collision load absorbed by the frame component may be reduced. Summary of the Invention

[0008] The object of the present invention is to increase the amount of collision load absorbed by a vehicle frame component configured to absorb collision loads transmitted via an impact-absorbing member and a front body structure having the vehicle frame component.

[0009] Technical means for solving technical problems

[0010] One aspect of the present invention is,

[0011] A vehicle frame component is provided, which extends in a longitudinal direction and forms a closed section with a cross-section orthogonal to the extending direction. The vehicle frame component is disposed behind an impact-absorbing component to absorb collision loads transmitted via the impact-absorbing component.

[0012] The vehicle frame component includes:

[0013] A first longitudinal wall, which extends vertically along the cross section;

[0014] The second longitudinal wall is disposed inside the vehicle width direction relative to the first longitudinal wall and extends in the vertical direction on the cross section;

[0015] The first transverse wall extends along the vehicle width direction in the cross section in such a way that the upper end of the first longitudinal wall and the upper end of the second longitudinal wall are connected to each other.

[0016] The second transverse wall extends along the vehicle width direction in the cross section in such a way that it connects the lower end of the first longitudinal wall to the lower end of the second longitudinal wall, and the second transverse wall together with the first longitudinal wall, the second longitudinal wall and the first transverse wall form the closed cross section.

[0017] A first inner wall, disposed in the vehicle width direction between the first longitudinal wall and the second longitudinal wall, and extending vertically in the cross section in a manner that connects the first transverse wall and the second transverse wall to each other; and

[0018] A second inner wall is disposed between the second longitudinal wall and the first inner wall in the vehicle width direction, and extends vertically in the cross section in a manner that connects the first transverse wall and the second transverse wall to each other.

[0019] The first transverse wall and the second transverse wall each have:

[0020] The first part connects the first longitudinal wall to the first inner wall;

[0021] The second part connects the first inner wall and the second inner wall to each other; and

[0022] The third part connects the second longitudinal wall and the second inner wall.

[0023] The bending stiffness of the first part and the bending stiffness of the third part are greater than the bending stiffness of the second part.

[0024] According to this structure, the bending stiffness of the first and third parts is greater than that of the second part. Therefore, compared to the case where the bending stiffness of the first and third parts is less than that of the second part, the support stiffness for supporting the impact-absorbing component can be ensured. Consequently, when a collision load is input to the front structure of the vehicle body from the front, the impact-absorbing component easily compresses along its extension direction, suppressing unintentional deformation of the impact-absorbing component. As a result, the collision load is easily and efficiently transferred from the impact-absorbing component to the vehicle frame component, increasing the amount of collision load absorbed by the vehicle frame component compared to the case where the impact-absorbing component deforms unintentionally.

[0025] If the bending stiffness of the second part is too large, it may hinder the compression of the vehicle frame member along its extension direction when a collision load is applied to it from the front. Therefore, in this embodiment, the bending stiffness of the second part is less than that of the first and third parts. Thus, compared to the case where the bending stiffness of the second part is greater than or equal to that of the first and third parts, the obstruction of the vehicle frame member's compression along its extension direction by the second part is suppressed. Consequently, even when a collision load is applied to the vehicle frame member from the front, the vehicle frame member can easily compress uniformly along its extension direction. As a result, compared to the case where the bending stiffness of the second part is greater than or equal to that of the first and third parts, the absorption capacity of the vehicle frame member for collision loads can be increased.

[0026] The effects of the invention

[0027] According to the present invention, in a vehicle frame component configured to absorb collision loads transmitted via an impact-absorbing member and in a front body structure having the vehicle frame component, the amount of collision load absorbed by the vehicle frame component can be increased. Attached Figure Description

[0028] Figure 1 This is a side view of the front structure of a vehicle body according to one embodiment of the present invention.

[0029] Figure 2 yes Figure 1 The top view of the front structure of the vehicle body is shown.

[0030] Figure 3 yes Figure 1 The top view of the upper structure shown.

[0031] Figure 4 yes Figure 1 The side view of the upper structure shown.

[0032] Figure 5 It is along Figure 3 A cross-sectional view of the VV line.

[0033] Figure 6 Viewed from the oblique rear Figure 3 The diagram shows a three-dimensional view of the beam.

[0034] Figure 7 It is along Figure 4 A sectional view along line VII-VII.

[0035] Figure 8 It is along Figure 7 A cross-sectional view of line VIII-VIII.

[0036] Symbol Explanation

[0037] 1. Front structure of the vehicle body; 2. Front bulkhead; 10. Upper structure; 11. Front side frame; 12. Main energy-absorbing box; 13. Main bumper reinforcement; 20. Lower structure; 21. Crossbeam; 21a. Joint; 22. Secondary energy-absorbing box; 22a. Longitudinal wall; 22b. Longitudinal wall; 22c. Longitudinal wall; 22d. Longitudinal wall; 22e. Transverse wall; 22f. Transverse wall; 23. Secondary bumper reinforcement; 24. Frame bracket; 30. Front subframe; 31. First longitudinal wall; 32. Second longitudinal wall; 33. First transverse wall; 34. Second transverse wall; s1. First part; s2. Second part; s3. Third part; 35. First inner wall; 36. Second inner wall; 37. Closed section; 37a. First closed section; 37b. Second closed section; 37c. Third closed section; A. Extension direction; C. Cabin; E. Engine compartment; T. Transverse direction. Detailed Implementation

[0038] The following description, with reference to the accompanying drawings, illustrates a vehicle frame component and a front body structure according to an embodiment of the present invention. Furthermore, the following description is merely illustrative and is not intended to limit the invention, its applications, or its uses.

[0039] Figure 1 This is a side view of the front structure 1 of the vehicle body in this embodiment. Figure 2 yes Figure 1 The diagram shows a top view of the front body structure 1. The front body structure 1 of this embodiment is a front body structure for automobiles and other vehicles. In the following description, the longitudinal direction, width direction, and vertical direction of the vehicle on which the front body structure 1 is mounted are sometimes referred to as the "longitudinal direction," "width direction," and "vertical direction," respectively. Furthermore, in the following description, the side facing the vehicle's centerline in the width direction is sometimes referred to as the "inner side in the width direction," and the side in the width direction opposite to the vehicle's centerline is sometimes referred to as the "outer side in the width direction." Additionally, the width direction is consistent with the left-right direction of the vehicle.

[0040] like Figure 1 As shown, the front structure 1 of the vehicle body includes an upper structure 10 and a lower structure 20 disposed below the upper structure 10. In the front structure 1 of this embodiment, the upper structure 10 and the lower structure 20 are configured to disperse and absorb the collision load received by the front structure 1 of the vehicle body in the event of a collision between the vehicle and other vehicles or obstacles.

[0041] Reference Figure 1 and Figure 2The upper structure 10 includes a pair of front side frames 11A and 11B, a pair of main energy-absorbing boxes 12A and 12B, and a main bumper reinforcement 13. In the following description, unless it is necessary to specifically distinguish each of the pair of front side frames 11A and 11B, one of the pair of front side frames 11A and 11B may be simply referred to as front side frame 11. Similarly, in the following description, unless it is necessary to specifically distinguish each of the pair of main energy-absorbing boxes 12A and 12B, one of the pair of main energy-absorbing boxes 12A and 12B may be simply referred to as main energy-absorbing box 12.

[0042] A pair of front side frames 11A and 11B are arranged spaced apart from each other in the vehicle width direction. The front side frame 11 extends in the longitudinal direction. The cross-section orthogonal to the extension direction of the front side frame 11 is formed as a closed cross-section. In this embodiment, the front side frame 11 is made of aluminum. In this specification, "aluminum" includes pure aluminum and aluminum alloys.

[0043] The front ends of the front side frames 11A and 11B are fixed to their respective main energy-absorbing boxes 12A and 12B. Specifically, the front side frame 11A is fixed to the main energy-absorbing box 12A, and the front side frame 11B is fixed to the main energy-absorbing box 12B. The rear end of the front side frame 11A is fixed to the front bulkhead 2 separating the compartment C and the engine compartment E.

[0044] The main energy-absorbing box 12 is a component used to absorb collision loads from the front. A pair of main energy-absorbing boxes 12A and 12B are arranged spaced apart from each other in the vehicle width direction. The main energy-absorbing box 12 extends in the longitudinal direction. The main energy-absorbing box 12 has a closed cross-section shape in a section orthogonal to the longitudinal direction. In this embodiment, the main energy-absorbing box 12 is made of aluminum.

[0045] The main energy-absorbing boxes 12A and 12B are respectively disposed between their respective front side brackets 11A and 11B and the main bumper reinforcement 13. The front ends of the main energy-absorbing boxes 12A and 12B are fixed to the main bumper reinforcement 13. Thus, the main energy-absorbing boxes 12A and 12B are connected to each other via the main bumper reinforcement 13. The rear ends of the main energy-absorbing boxes 12A and 12B are fixed to their respective front side brackets 11A and 11B. Specifically, the rear end of the main energy-absorbing box 12A is fixed to the front side bracket 11A, and the rear end of the main energy-absorbing box 12B is fixed to the front side bracket 11B.

[0046] The main bumper reinforcement 13 extends along the width of the vehicle. The front ends of the main energy-absorbing boxes 12A and 12B are fixed to the main bumper reinforcement 13. Thus, the main bumper reinforcement 13 connects the main energy-absorbing boxes 12A and 12B to each other.

[0047] When a collision load is input to the main bumper reinforcement 13 from the front, a portion of the collision load is absorbed by the main energy-absorbing box 12 and the front side frame 11. Specifically, when a collision load is input to the main bumper reinforcement 13 from the front, the main energy-absorbing box 12 and the front side frame 11 are compressed in the longitudinal direction, thereby absorbing a portion of the collision load.

[0048] Figure 3 This is a top view of the lower structure 20. Figure 4 This is a side view of the lower structure 20. (Refer to...) Figure 3 and Figure 4 The lower structure 20 includes a pair of front subframes 30A and 30B, a crossbeam 21, a pair of secondary energy-absorbing boxes 22A and 22B, and a secondary bumper reinforcement 23. In the following description, unless it is necessary to specifically distinguish each of the pair of front subframes 30A and 30B, one of them may sometimes be simply referred to as front subframe 30. Similarly, in the following description, unless it is necessary to specifically distinguish each of the pair of secondary energy-absorbing boxes 22A and 22B, one of them may sometimes be simply referred to as secondary energy-absorbing box 22.

[0049] A pair of front subframes 30A and 30B are arranged spaced apart from each other in the vehicle width direction. The front subframes 30 extend along a direction inclined outward in the forward direction (hereinafter, sometimes referred to as the extension direction A). Specifically, the right front subframe 30A extends along a direction inclined to the right in the forward direction, and the left front subframe 30B extends along a direction inclined to the left in the forward direction. Thus, the pair of front subframes 30A and 30B extend apart from each other as they move forward. In the following description, the extension direction A of the front side frame 11 is sometimes simply referred to as extension direction A, and the horizontal direction in the plane orthogonal to extension direction A is sometimes referred to as lateral direction T. Furthermore, extension direction A is aligned with the axial direction of the front subframes 30. The front subframe 30 of this embodiment is an example of a vehicle frame component according to the present invention.

[0050] The front end of the front sub-frame 30 is fixed to the crossbeam 21. The rear end of the front sub-frame 30 is mounted to other structures via frame brackets 24, such as a battery casing (not shown) for housing a battery (not shown). Figure 1 As shown, the front subframe 30 is positioned below the front side frame 11.

[0051] The front sub-frame 30 is an aluminum extrusion. As a result, the cross-sectional shape of the front sub-frame 30 at the section orthogonal to the extension direction A is substantially the same along the entire length of the extension direction A.

[0052] Figure 5 It is along Figure 3 A cross-sectional view of the VV line. Figure 5This is a sectional view showing the section of the front subframe 30 orthogonal to the extension direction A. Figure 5 The left-right direction in the middle is consistent with the horizontal direction of T. Furthermore, the more... Figure 5 The more the right side of the vehicle is located on the outer side in the width direction, the more... Figure 5 The left side of the center is located inside the vehicle width direction. See below for reference. Figure 5 The front subframe 30A is described in detail, but the front subframe 30B also has the same structure as the front subframe 30A.

[0053] Reference Figure 5 The front sub-frame 30 includes a first longitudinal wall 31, a second longitudinal wall 32, a first transverse wall 33, a second transverse wall 34, a first inner wall 35, and a second inner wall 36. The front sub-frame 30... Figure 5 The cross-section shown is a rectangular closed section.

[0054] The first longitudinal wall 31 is a plate-shaped structure with its length direction A, its width direction vertically, and its thickness direction transversely T. The first longitudinal wall 31 is... Figure 5 The cross-section shown extends vertically. The first longitudinal wall 31 forms part of the shape of the front subframe 30. Specifically, the first longitudinal wall 31 forms the outer sidewall of the front subframe 30 in the vehicle width direction.

[0055] The second longitudinal wall 32 is a plate-shaped structure with its length direction A, its width direction vertically, and its thickness direction transversely T. The second longitudinal wall 32 is... Figure 5 The cross-section shown extends vertically. The second longitudinal wall 32 forms part of the outer shape of the front subframe 30. Specifically, the second longitudinal wall 32 forms an inner side wall in the vehicle width direction of the front subframe 30. The second longitudinal wall 32 is disposed inside the vehicle width direction relative to the first longitudinal wall 31. The second longitudinal wall 32 is spaced apart from the first longitudinal wall 31 in the vehicle width direction.

[0056] The first transverse wall 33 is a plate-shaped structure with its length direction A, its width direction T, and its thickness direction vertically. The first transverse wall 33 is... Figure 5 The cross-section shown extends laterally along the transverse direction T, connecting the upper ends of the first longitudinal wall 31 and the second longitudinal wall 32. In other words, the first transverse wall 33 extends along the vehicle width direction, connecting the upper ends of the first longitudinal wall 31 and the second longitudinal wall 32. The first transverse wall 33 forms part of the outer shape of the front subframe 30. Specifically, the first transverse wall 33 forms the upper wall of the front subframe 30.

[0057] The second transverse wall 34 is a plate-shaped structure with its length direction A, its width direction T, and its thickness direction vertically. The second transverse wall 34 is... Figure 5The cross-section shown extends laterally along the transverse T such that the lower ends of the first longitudinal wall 31 and the second longitudinal wall 32 are interconnected. In other words, the second transverse wall 34 extends along the vehicle width direction such that the lower ends of the first longitudinal wall 31 and the lower ends of the second longitudinal wall 32 are interconnected. The second transverse wall 34 forms part of the outer shape of the front subframe 30. Specifically, the second transverse wall 34 forms the lower wall of the front subframe 30. The second transverse wall 34 is positioned below the first transverse wall 33. The second transverse wall 34 is spaced apart from the first transverse wall 33 in the vertical direction.

[0058] The first transverse wall 33 and the second transverse wall 34 each have a first part s1, a second part s2, and a third part s3. The first part s1 is... Figure 5 The cross-section shown extends transversely along T in a manner that connects the first longitudinal wall 31 and the first inner wall 35. The second part s2... Figure 5 The cross-section shown extends transversely along T in a manner that connects the first inner wall 35 and the second inner wall 36 to each other. The third part s3 is... Figure 5 The cross-section shown extends along the transverse T in such a way that the second longitudinal wall 32 and the second inner wall 36 are connected to each other.

[0059] The first inner wall 35 is a plate-shaped structure with its length direction A, its width direction vertically, and its thickness direction transversely T. The first inner wall 35 is... Figure 5 The cross-section shown extends vertically in a manner that connects the first transverse wall 33 and the second transverse wall 34. The first inner wall 35 is disposed in the transverse direction T between the first longitudinal wall 31 and the second longitudinal wall 32. In other words, the first inner wall 35 is disposed in the vehicle width direction between the first longitudinal wall 31 and the second longitudinal wall 32.

[0060] The second inner wall 36 is a plate-shaped structure with its length direction A, its width direction vertically, and its thickness direction transversely T. The second inner wall 36 is... Figure 5 The cross-section shown extends vertically to connect the first transverse wall 33 and the second transverse wall 34. The second inner wall 36 is disposed in the transverse direction T between the second longitudinal wall 32 and the first inner wall 35. In other words, the second inner wall 36 is disposed inside the first inner wall 35 in the vehicle width direction.

[0061] like Figure 5As shown, the front sub-frame 30 has a closed section 37 formed by a first longitudinal wall 31, a second longitudinal wall 32, a first transverse wall 33, and a second transverse wall 34. In other words, the first longitudinal wall 31, the second longitudinal wall 32, the first transverse wall 33, and the second transverse wall 34 form the closed section 37 that constitutes the outer shape of the front sub-frame 30. Furthermore, the first portion s1 of each of the first longitudinal wall 31, the first inner wall 35, the first transverse wall 33, and the second transverse wall 34 forms a first closed section 37a. The second portion s2 of each of the first inner wall 35, the second inner wall 36, the first transverse wall 33, and the second transverse wall 34 forms a second closed section 37b. The third portion s3 of each of the second longitudinal wall 32, the second inner wall 36, the first transverse wall 33, and the second transverse wall 34 forms a third closed section 37c. The areas of the first closed section 37a, the second closed section 37b, and the third closed section 37c are the same.

[0062] In this specification, the area of ​​a closed section refers to the area of ​​a section orthogonal to the extension direction A (e.g., Figure 5 The total area of ​​the plurality of walls forming the closed section (as shown in the cross-section) does not include the area of ​​the region surrounded by the plurality of walls forming the closed section. Furthermore, in this specification, "the area of ​​the first closed section 37a, the area of ​​the second closed section 37b, and the area of ​​the third closed section 37c are the same as each other" includes, strictly speaking, that the areas of the first closed section 37a, the second closed section 37b, and the third closed section 37c are the same as each other, and that they are substantially the same as each other within a range where the front sub-frame 30 does not experience local buckling. In this embodiment, two of the areas of the first closed section 37a, the second closed section 37b, and the third closed section 37c are within the range of 90% to 110% of the area of ​​the other.

[0063] In this embodiment, Figure 5 In the cross-section shown, the first closed section 37a, the second closed section 37b, and the third closed section 37c are approximately the same as each other. Specifically, the heights of the first longitudinal wall 31, the second longitudinal wall 32, the first inner wall 35, and the second inner wall 36, i.e., their dimensions in the vertical direction, are approximately the same as each other, and the widths of the first part s1, the second part s2, and the third part s3, i.e., their dimensions in the horizontal direction T, are approximately the same as each other.

[0064] The bending stiffness of the first longitudinal wall 31 is greater than that of the second longitudinal wall 32. Furthermore, the bending stiffness of the second longitudinal wall 32 is greater than that of the first inner wall 35. Further, the bending stiffness of the first inner wall 35 is greater than that of the second inner wall 36. In other words, the bending stiffness of the first longitudinal wall 31, the second longitudinal wall 32, the first inner wall 35, and the second inner wall 36 decreases in the following order: first longitudinal wall 31, second longitudinal wall 32, first inner wall 35, and second inner wall 36.

[0065] In this specification, the bending stiffness of the plate-shaped member comprising the first longitudinal wall 31, the second longitudinal wall 32, the first transverse wall 33, the second transverse wall 34, the first inner wall 35, and the second inner wall 36 is the bending stiffness relative to the bending moment loaded along the thickness direction of the plate-shaped member from both ends in the length direction of each plate-shaped member, i.e., from both ends in the extension direction A of each plate-shaped member.

[0066] In this embodiment, by setting the thickness t31 of the first longitudinal wall 31 (i.e., the dimension in the transverse direction T) to be greater than the thickness t32 of the second longitudinal wall 32, the bending stiffness of the first longitudinal wall 31 is greater than that of the second longitudinal wall 32. Furthermore, by setting the thickness t32 of the second longitudinal wall 32 to be greater than the thickness t35 of the first inner wall 35, the bending stiffness of the second longitudinal wall 32 is greater than that of the first inner wall 35. Similarly, by setting the thickness t35 of the first inner wall 35 to be greater than the thickness t36 of the second inner wall 36, the bending stiffness of the first inner wall 35 is greater than that of the second inner wall 36. Moreover, as described above, the heights (vertical dimensions) of the first longitudinal wall 31, the second longitudinal wall 32, the first inner wall 35, and the second inner wall 36 are approximately the same.

[0067] The bending stiffness of the first part s1 is greater than that of the second part s2. Similarly, the bending stiffness of the third part s3 is greater than that of the second part s2. Furthermore, the bending stiffness of the first part s1 and the third part s3 are the same. In this embodiment, the bending stiffness of the first part s1 is greater than that of the second part s2 by setting the thickness ts1 (vertical dimension) of the first part s1 to be greater than that of the second part s2. Likewise, in this embodiment, the bending stiffness of the third part s3 is greater than that of the second part s2 by setting the thickness ts3 (vertical dimension) of the third part s3 to be greater than that of the second part s2. Moreover, as described above, the widths (transverse dimensions T) of the first part s1, the second part s2, and the third part s3 are approximately the same.

[0068] Reference Figure 3 The crossbeam 21 extends along the vehicle width direction to connect the front ends of the front subframes 30A and 30B to each other. The crossbeam 21 is an extruded aluminum part. In addition, the crossbeam 21 has a closed section shape in a section orthogonal to the vehicle width direction.

[0069] Figure 6 This is a three-dimensional view of beam 21 viewed from a diagonal rear angle. (For example...) Figure 6As shown, a joint 21a is formed on the rear side of the crossbeam 21, where the crossbeam 21 joins with the front sub-frame 30. In this embodiment, the joint 21a is a weld mark created by welding the crossbeam 21 to the front sub-frame 30. In this embodiment, the first portion s1 and the third portion s3 of each of the first longitudinal wall 31, the second longitudinal wall 32, the first transverse wall 33, and the second transverse wall 34 are welded relative to the crossbeam 21.

[0070] Reference Figure 3 The secondary energy-absorbing box 22 is a component used to absorb collision loads from the oblique front. A pair of secondary energy-absorbing boxes 22A and 22B are arranged spaced apart from each other in the vehicle width direction. The secondary energy-absorbing boxes 22 extend outward in the forward direction in the vehicle width direction. Specifically, secondary energy-absorbing box 22A extends to the right in the forward direction, and secondary energy-absorbing box 22B extends to the left in the forward direction. The main energy-absorbing box 12 in this embodiment is made of aluminum. The secondary energy-absorbing box 22 of this embodiment is an example of the impact absorption component of the present invention.

[0071] The secondary energy-absorbing box 22 is disposed between the crossbeam 21 and the secondary bumper reinforcement 23. The front end of the secondary energy-absorbing box 22 is welded to the secondary bumper reinforcement 23. Thus, the secondary energy-absorbing boxes 22A and 22B are connected to each other via the secondary bumper reinforcement 23. The rear end of the secondary energy-absorbing box 22 is welded to the crossbeam 21.

[0072] The secondary energy-absorbing boxes 22A and 22B extend in the same direction as their respective front secondary frames 30A and 30B. In other words, the secondary energy-absorbing boxes 22A and 22B extend along the extension direction A of their respective front secondary frames 30A and 30B. Furthermore, the axis L1 of the secondary energy-absorbing boxes 22A and 22B coincides with the axis L2 of their respective front secondary frames 30A and 30B. Here, "the axis L1 of the secondary energy-absorbing boxes 22A and 22B coincides with the axis L2 of their respective front secondary frames 30A and 30B" includes both a strictly consistent alignment of the axis L1 of the secondary energy-absorbing boxes 22A and 22B with the axis L2 of their respective front secondary frames 30A and 30B, and a slight misalignment of the axis L1 of the secondary energy-absorbing boxes 22A and 22B from the axis L2 of their respective front secondary frames 30A and 30B due to installation errors that may occur during manufacturing.

[0073] Although not shown in the diagram, the secondary energy-absorbing box 22 has the same closed-section shape as the front secondary frame 30 in a section orthogonal to the extension direction A. The secondary energy-absorbing box 22 has four longitudinal walls 22a to 22d. Figure 7 (shown in the image) and two transverse walls 22e, 22f ( Figure 8As shown in the diagram, the four longitudinal walls 22a-22d extend vertically along a section orthogonal to the extension direction A and are spaced apart from each other in the transverse direction T. The two transverse walls 22e and 22f extend horizontally along a section orthogonal to the extension direction A and are spaced apart from each other in the vertical direction. The upper transverse wall 22e connects the upper ends of the four longitudinal walls 22a-22d to each other, and the lower transverse wall 22f connects the lower ends of the four longitudinal walls 22a-22d to each other. In the following description, the transverse wall 22e is sometimes referred to as the upper wall 22e, and the transverse wall 22f as the lower wall 22f.

[0074] Figure 7 It is along Figure 4 A sectional view along line VII-VII. (See example...) Figure 7 As shown, the four longitudinal walls 22a-22d of the secondary energy-absorbing box 22 are aligned with the corresponding first longitudinal wall 31, first inner wall 35, second inner wall 36, and second longitudinal wall 32 of the front secondary frame 30 in the transverse direction T. The alignment of the walls of the secondary energy-absorbing box 22 with the walls of the front secondary frame 30 in the transverse direction T means that these walls overlap each other wholly or partially in the transverse direction T.

[0075] Figure 8 It is along Figure 7 A cross-sectional view along line VIII-VIII. (See example...) Figure 8 As shown, the two transverse walls 22e and 22f of the secondary energy-absorbing box 22 are aligned vertically with the corresponding first transverse wall 33 and second transverse wall 34 of the front secondary frame 30. The vertical alignment of the walls of the secondary energy-absorbing box 22 with the walls of the front secondary frame 30 means that these walls overlap each other entirely or partially in the vertical direction.

[0076] The secondary bumper reinforcement 23 extends along the width of the vehicle. The front ends of the secondary energy-absorbing boxes 22A and 22B are fixed to the secondary bumper reinforcement 23. Thus, the secondary bumper reinforcement 23 connects the secondary energy-absorbing boxes 22A and 22B to each other.

[0077] When a collision load is input from the sub-bumper reinforcement 23 in the forward-sloping direction, a portion of the collision load is absorbed by the sub-energy-absorbing box 22 and the front sub-frame 30. Specifically, when a collision load is input from the sub-bumper reinforcement 23 in the forward-sloping direction, the sub-energy-absorbing box 22 and the front sub-frame 30 are compressed along the extension direction A, thereby absorbing the input collision load.

[0078] The front body structure 1 and front subframe 30 according to this embodiment have the following effects.

[0079] (1) A vehicle frame component (in this embodiment, a front subframe) 30, which extends in a longitudinal direction and forms a closed section with a cross-section orthogonal to the extension direction A, and is disposed behind an impact-absorbing component (in this embodiment, a secondary energy-absorbing box) 22, configured to absorb the collision load transmitted via the impact-absorbing component 22, wherein,

[0080] Vehicle frame components 30 include:

[0081] The first longitudinal wall 31 extends in the vertical direction in the cross section;

[0082] The second longitudinal wall 32 is disposed inside the vehicle width direction relative to the first longitudinal wall 31 and extends in the vertical direction in the cross section;

[0083] The first transverse wall 33 extends along the vehicle width direction in cross section in such a way that the upper end of the first longitudinal wall 31 and the upper end of the second longitudinal wall 32 are connected to each other.

[0084] The second transverse wall 34 extends along the vehicle width direction in the cross section in such a way that the lower end of the first longitudinal wall 31 and the lower end of the second longitudinal wall 32 are connected to each other, and the second transverse wall 34 together with the first longitudinal wall 31, the second longitudinal wall 32 and the first transverse wall 33 form a closed cross section shape.

[0085] A first inner wall 35 is disposed between the first longitudinal wall 31 and the second longitudinal wall 32 in the vehicle width direction, and extends vertically in cross-section in a manner that connects the first transverse wall 33 and the second transverse wall 34 to each other; and

[0086] The second inner wall 36 is disposed between the second longitudinal wall 32 and the first inner wall 35 in the vehicle width direction, and extends vertically in the cross section in a manner that connects the first transverse wall 33 and the second transverse wall 34 to each other.

[0087] The first transverse wall 33 and the second transverse wall 34 each possess:

[0088] The first part s1 connects the first longitudinal wall 31 and the first inner wall 35 to each other;

[0089] The second part s2 connects the first inner wall 35 and the second inner wall 36 to each other; and

[0090] The third part s3 connects the second longitudinal wall 32 and the second inner wall 36.

[0091] The bending stiffness of the first part s1 and the bending stiffness of the third part s3 are greater than the bending stiffness of the second part s2.

[0092] According to this embodiment, the bending stiffness of the first part s1 and the bending stiffness of the third part s3 are greater than the bending stiffness of the second part s2. Therefore, compared to the case where the bending stiffness of the first part s1 and the bending stiffness of the third part s3 are less than the bending stiffness of the second part s2, the support stiffness for supporting the impact-absorbing member 22 can be ensured. As a result, when a collision load is input from the front to the front structure of the vehicle body, the impact-absorbing member 22 is easily compressed along the extension direction A, suppressing unintentional deformation of the impact-absorbing member 22. Consequently, the collision load is easily and efficiently transferred from the impact-absorbing member 22 to the vehicle frame member 30, and the amount of collision load absorbed by the vehicle frame member 30 can be increased compared to the case where the impact-absorbing member 22 is unintentionally deformed.

[0093] If the bending stiffness of the second portion s2 is too large, it may hinder the compression of the vehicle frame member 30 along the extension direction A when a collision load is input to the vehicle frame member 30 from the front. Therefore, in this embodiment, the bending stiffness of the second portion s2 is less than the bending stiffness of the first portion s1 and the bending stiffness of the third portion s3. Thus, compared to the case where the bending stiffness of the second portion s2 is greater than or equal to the bending stiffness of the first portion s1 and the third portion s3, the obstruction of the second portion s2 from the compression of the vehicle frame member 30 along the extension direction A is suppressed. Consequently, even when a collision load is input to the vehicle frame member 30 from the front, the vehicle frame member 30 can easily compress uniformly along the extension direction A. As a result, compared to the case where the bending stiffness of the second portion s2 is greater than or equal to the bending stiffness of the first portion s1 and the third portion s3, the amount of collision load absorbed by the vehicle frame member 30 can be increased.

[0094] (2) The first portion s1 of each of the first longitudinal wall 31, the first inner wall 35, the first transverse wall 33, and the second transverse wall 34 forms a first closed section 37a on the cross section. The second portion s2 of each of the first inner wall 35, the second inner wall 36, the first transverse wall 33, and the second transverse wall 34 forms a second closed section 37b on the cross section. The third portion s3 of each of the second longitudinal wall 32, the second inner wall 36, the first transverse wall 33, and the second transverse wall 34 forms a third closed section 37c on the cross section. The areas of the first closed section 37a, the second closed section 37b, and the third closed section 37c are the same. Therefore, the second moment of each closed section is the same relative to the bending moment loaded at both ends in the extension direction A of the vehicle frame member 30. As a result, local buckling in the vehicle frame member 30 can be suppressed, the vehicle frame member 30 can be easily compressed uniformly along the extension direction A, and the absorption of collision load by the vehicle frame member 30 can be improved.

[0095] (3) The vehicle frame component 30 is a front subframe 30 disposed below the front side frame 11, which is located on the outer side of the engine compartment E in the vehicle width direction. As a result, even when configured to absorb collision loads in the longitudinal direction of the vehicle by means of the front side frame 11 extending in the longitudinal direction and to absorb collision loads from the oblique front of the vehicle along the extension direction A by means of the front subframe 30, the front subframe 30 is also able to adequately absorb collision loads in the longitudinal direction of the vehicle.

[0096] (4) The front structure 1 of the vehicle body in this embodiment includes a vehicle frame member 30 and an impact absorption member (in this embodiment, a secondary energy absorption box) 22 disposed in front of the vehicle frame member. The axis L1 of the impact absorption member 22 is aligned with the axis L2 of the vehicle frame member 30. As a result, the collision load can be easily transferred from the impact absorption member 22 to the vehicle frame member 30, thereby increasing the amount of collision load absorbed by the vehicle frame member 30.

[0097] (5) The impact-absorbing component 22 includes: an upper wall 22e extending in the vehicle width direction in cross-section; and a lower wall 22f disposed below the upper wall 22e at a distance from it, and extending in the vehicle width direction in cross-section. The upper wall 22e and lower wall 22f of the impact-absorbing component 22 are aligned vertically with the first transverse wall 33 and the second transverse wall 34 of their respective vehicle frame components 30. As a result, the collision load can be easily transferred from the upper wall 22e and lower wall 22f of the impact-absorbing component 22 to the first transverse wall 33 and the second transverse wall 34 of the vehicle frame components 30. Consequently, the vehicle frame components 30 can be easily compressed uniformly in the extension direction A, thereby increasing the amount of collision load absorbed by the vehicle frame components 30.

[0098] Furthermore, the present invention is not limited to the structure described in the above embodiments, but can be modified in various ways.

[0099] In the above embodiments, the front subframe 30 is described as an example of the vehicle frame component involved in the present invention, but it is not limited thereto. The vehicle frame component involved in the present invention may also be other frame components.

[0100] In the above embodiment, the front sub-frame 30 has two inner walls, a first inner wall 35 and a second inner wall 36, but it is not limited to this and may also have three or more inner walls.

[0101] In the above embodiments, the thicknesses t31 of the first longitudinal wall 31, t32 of the second longitudinal wall 32, t35 of the first inner wall 35, and t36 of the second inner wall 36 are different from each other, but are not limited to this, and can also be the same thickness.

[0102] In the above embodiment, the secondary energy-absorbing box 22 has the same cross-sectional shape as the front secondary frame 30 on the cross-section orthogonal to the extension direction A, but is not limited to this.

[0103] [Postscript]

[0104] The present invention includes the following methods.

[0105] [Method 1]

[0106] A vehicle frame component extends in a longitudinal direction, and a section orthogonal to the extending direction forms a closed section. The vehicle frame component is positioned behind an impact-absorbing component to absorb collision loads transmitted via the impact-absorbing component.

[0107] The vehicle frame component includes:

[0108] A first longitudinal wall, which extends vertically along the cross section;

[0109] The second longitudinal wall is disposed inside the vehicle width direction relative to the first longitudinal wall and extends in the vertical direction on the cross section;

[0110] The first transverse wall extends along the vehicle width direction in the cross section in such a way that the upper end of the first longitudinal wall and the upper end of the second longitudinal wall are connected to each other.

[0111] The second transverse wall extends along the vehicle width direction in the cross section in such a way that it connects the lower end of the first longitudinal wall to the lower end of the second longitudinal wall, and the second transverse wall together with the first longitudinal wall, the second longitudinal wall and the first transverse wall form the closed cross section.

[0112] A first inner wall, disposed in the vehicle width direction between the first longitudinal wall and the second longitudinal wall, and extending vertically in the cross section in a manner that connects the first transverse wall and the second transverse wall to each other; and

[0113] A second inner wall is disposed between the second longitudinal wall and the first inner wall in the vehicle width direction, and extends vertically in the cross section in a manner that connects the first transverse wall and the second transverse wall to each other.

[0114] The first transverse wall and the second transverse wall each have:

[0115] The first part connects the first longitudinal wall to the first inner wall;

[0116] The second part connects the first inner wall and the second inner wall to each other; and

[0117] The third part connects the second longitudinal wall and the second inner wall.

[0118] The bending stiffness of the first part and the bending stiffness of the third part are greater than the bending stiffness of the second part.

[0119] [Method 2]

[0120] The vehicle frame components described in Method 1, wherein,

[0121] The first portion of each of the first longitudinal wall, the first inner wall, the first transverse wall, and the second transverse wall forms a first closed section on the cross-section.

[0122] The second portion of each of the first inner wall, the second inner wall, the first transverse wall, and the second transverse wall forms a second closed section on the cross-section.

[0123] The third portions of the second longitudinal wall, the second inner wall, and the first transverse wall and the second transverse wall respectively form a third closed section on the cross-section.

[0124] The areas of the first closed section, the second closed section, and the third closed section are all the same.

[0125] [Method 3]

[0126] The vehicle frame components described in method 1 or 2, wherein,

[0127] The vehicle frame component is a front subframe located below the front side frame, which is positioned on the outer side of the engine compartment in the vehicle width direction.

[0128] [Method 4]

[0129] A front structure for a vehicle body, comprising:

[0130] The vehicle frame component described in any one of methods 1 to 3; and

[0131] The impact-absorbing component is located at the front of the vehicle frame component.

[0132] The axis of the impact-absorbing component is aligned with the axis of the vehicle frame component.

[0133] [Method 5]

[0134] The front structure of the vehicle body described in Method 4, wherein,

[0135] The impact-absorbing component includes:

[0136] Upper wall, which extends along the vehicle width direction in the cross section; and

[0137] A lower wall, which is spaced apart from the upper wall and disposed below the upper wall, extends along the vehicle width direction in the cross-section.

[0138] The upper and lower walls of the impact-absorbing component are aligned vertically with the first and second transverse walls of their respective vehicle frame components.

Claims

1. A vehicle frame member extending in a longitudinal direction, wherein a section orthogonal to the extending direction forms a closed section, and the vehicle frame member is disposed behind an impact-absorbing member to absorb collision loads transmitted via the impact-absorbing member, characterized in that, The vehicle frame component includes: A first longitudinal wall, which extends vertically along the cross section; The second longitudinal wall is disposed inside the vehicle width direction relative to the first longitudinal wall and extends in the vertical direction on the cross section; The first transverse wall extends along the vehicle width direction in the cross section in such a way that the upper end of the first longitudinal wall and the upper end of the second longitudinal wall are connected to each other. The second transverse wall extends along the vehicle width direction in the cross section in such a way that it connects the lower end of the first longitudinal wall to the lower end of the second longitudinal wall, and the second transverse wall together with the first longitudinal wall, the second longitudinal wall and the first transverse wall form the closed cross section. A first inner wall is disposed between the first longitudinal wall and the second longitudinal wall in the vehicle width direction, and extends vertically in the cross section in such a way as to connect the first transverse wall and the second transverse wall to each other. as well as A second inner wall is disposed between the second longitudinal wall and the first inner wall in the vehicle width direction, and extends vertically in the cross section in a manner that connects the first transverse wall and the second transverse wall to each other. The first transverse wall and the second transverse wall each have: The first part connects the first longitudinal wall to the first inner wall; The second part connects the first inner wall and the second inner wall to each other; and The third part connects the second longitudinal wall and the second inner wall to each other. The bending stiffness of the first part and the bending stiffness of the third part are greater than the bending stiffness of the second part.

2. The vehicle frame component according to claim 1, characterized in that, The first portion of each of the first longitudinal wall, the first inner wall, the first transverse wall, and the second transverse wall forms a first closed section on the cross-section. The second portion of each of the first inner wall, the second inner wall, the first transverse wall, and the second transverse wall forms a second closed section on the cross-section. The third portions of the second longitudinal wall, the second inner wall, and the first transverse wall and the second transverse wall respectively form a third closed section on the cross-section. The areas of the first closed section, the second closed section, and the third closed section are all the same.

3. The vehicle frame component according to claim 1 or 2, characterized in that, The vehicle frame component is a front subframe located below the front side frame, which is positioned on the outer side of the engine compartment in the vehicle width direction.

4. A front structure of a vehicle body, characterized in that, have: The vehicle frame component as described in claim 1 or 2; and The impact-absorbing component is located at the front of the vehicle frame component. The axis of the impact-absorbing component is aligned with the axis of the vehicle frame component.

5. The front structure of the vehicle body according to claim 4, characterized in that, The impact-absorbing component includes: Upper wall, which extends along the vehicle width direction in the cross section; and A lower wall, which is spaced apart from the upper wall and disposed below the upper wall, extends along the vehicle width direction in the cross-section. The upper and lower walls of the impact-absorbing component are aligned vertically with the first and second transverse walls of their respective vehicle frame components.

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