Load-receiving member of vehicle and vehicle front structure

Abstract

The main input direction of a load to be absorbed is defined as a first direction, one direction intersecting the first direction is defined as a second direction, and another direction intersecting the first direction and the second direction is defined as a third direction. A load-receiving member of a vehicle is provided with a substantially S-shaped cross section. The substantially S-shaped cross-section is formed by connecting a one-side opening and an other-side opening in the third direction. The one-side opening is opened in a substantially U-shape on one side in the second direction as seen from the first direction. The other-side opening is opened in a substantially U-shape on the other side in the second direction as seen from the first direction.

Description

Vehicle load-bearing member and vehicle front structure

[0001] The present invention relates to a load-receiving member for a vehicle that absorbs the energy of an input impact load, and to a vehicle front structure.

[0002] A vehicle front structure has been proposed in which a load receiving portion (energy absorbing portion) is integrally formed with a part of a wheel house (see, for example, Patent Document 1).

[0003] The vehicle front structure described in Patent Document 1 has a load receiving portion (energy absorbing portion) that is integrally formed on the upper wall of a wheelhouse made of aluminum alloy and extends substantially along the longitudinal direction of the vehicle. The load receiving portion has a plurality of substantially C-shaped reinforcing ribs formed on the inner surface of a channel-shaped beam that extends substantially along the longitudinal direction of the vehicle and that are spaced apart in the longitudinal direction of the vehicle.

[0004] In this load-receiving portion, sections with and without approximately C-shaped reinforcing ribs are alternately arranged on the inner surface of the beam, so that when an impact load is input from the front, the sections without reinforcing ribs can collapse like bellows. Therefore, this load-receiving portion can efficiently absorb the energy of the impact load by collapsing like bellows in the sections without reinforcing ribs.

[0005] US Patent Application Publication No. 2023 / 0373563

[0006] In the vehicle front structure described in Patent Document 1, a load receiving portion, which is a portion for absorbing the energy of an impact load, is integrally formed with a portion of the upper wall of the curtain-shaped wall of the wheelhouse. Therefore, the upper wall portion of the wheelhouse where the load receiving portion is located efficiently absorbs the energy of the impact load by the load receiving portion collapsing like a bellows when an impact load is input, but the other curtain-shaped wall portions do not contribute significantly to energy absorption. In other words, in the vehicle front structure described in Patent Document 1, the difference in rigidity between the load receiving portion of the upper wall of the wheelhouse and the other curtain-shaped wall portions is extremely large, making it difficult to effectively utilize a wide range of the vehicle mounted member for absorbing the energy of the impact load.

[0007] The problem to be solved is to enable a wide range of vehicle mounting members to be effectively used for absorbing the energy of an impact load. By solving this problem, the present invention aims to improve collision safety performance.

[0008] A load-receiving member of a vehicle according to one embodiment of the present invention is characterized in that, when the main input direction of the load to be absorbed is defined as a first direction, a direction intersecting the first direction as a second direction, and another direction intersecting the first direction and the second direction as a third direction, the load-receiving member has an approximately S-shaped cross-section formed by connecting a one-side opening that opens in an approximately U-shape on one side of the second direction when viewed from the first direction, and a other-side opening that opens in an approximately U-shape on the other side of the second direction when viewed from the first direction, in the third direction.

[0009] With the above configuration, when an impact load is applied from the first direction to a substantially S-shaped cross-section having one side opening and the other side opening connected in the third direction, the applied load is dispersed over a wide area of ​​the substantially S-shaped cross-section by the walls (surfaces) facing in multiple directions that constitute the substantially S-shaped cross-section. Furthermore, the impact load applied to the substantially S-shaped cross-section is smoothly transmitted in the first direction along the multiple corners (ridges) of the substantially S-shaped cross-section that extend along the first direction. Unlike structures with partially closed cross-sections, the substantially S-shaped cross-section is less likely to experience partial rigidity differences across almost the entire area. Therefore, the load is transmitted approximately evenly across the entire area of ​​the substantially S-shaped cross-section. Therefore, when an impact load is applied from the first direction, the entire area of ​​the substantially S-shaped cross-section deforms approximately evenly, thereby efficiently absorbing the energy of the impact load.

[0010] A vehicle front structure according to one embodiment of the present invention is a vehicle front structure having a load-receiving member that extends approximately along the fore-and-aft direction of the vehicle, has a bumper beam connected to its front end, and has a suspension support structure connected to its rear end, and is characterized in that the load-receiving member has an approximately S-shaped cross-section in which an inner opening that opens in an approximately U-shape on the inside in the vehicle width direction when viewed from the front of the vehicle, and an outer opening that opens in an approximately U-shape on the outside in the vehicle width direction when viewed from the front of the vehicle, are connected in the vertical direction of the vehicle.

[0011] With the above configuration, when an impact load is applied from the front of the vehicle to a substantially S-shaped cross-section in which the inner opening and the outer opening are connected in the vehicle vertical direction, the applied load is dispersed over a wide area of ​​the S-shaped cross-section by the walls (surfaces) facing in multiple directions that constitute the substantially S-shaped cross-section. Furthermore, the impact load applied to the substantially S-shaped cross-section is smoothly transmitted to the rear of the vehicle along the multiple corners (ridges) of the substantially S-shaped cross-section that extend along the vehicle longitudinal direction. Unlike a structure in which a closed cross-section is provided only partially in the vertical direction, the substantially S-shaped cross-section is less likely to experience partial rigidity differences across almost the entire vertical area. Therefore, the load is transmitted approximately evenly across the entire substantially S-shaped cross-section. Therefore, when an impact load is applied from the front of the vehicle, the entire substantially S-shaped cross-section deforms approximately evenly, thereby efficiently absorbing the energy of the impact load.

[0012] It is desirable that the substantially S-shaped cross section is configured by a plurality of connected portions in the vertical direction of the vehicle.

[0013] In this case, the impact load can be dispersed and transmitted in the vertical and width directions by the multiple approximately S-shaped cross-sections connected in the vertical direction of the vehicle. Furthermore, because the multiple approximately S-shaped cross-sections are connected in the vertical direction of the vehicle, the shape can be changed relatively freely while maintaining the basic function described above. Therefore, when this configuration is adopted, it becomes possible to increase the degree of freedom in changing the design and specifications of the vehicle.

[0014] The inner walls in the vehicle width direction of the outer openings adjacent to each other in the vertical direction of the vehicle may be set to be offset in the vehicle width direction when viewed from the front of the vehicle.

[0015] In this case, the inner walls of the outer openings adjacent to each other in the vertical direction of the vehicle are offset in the vehicle width direction, so that the inner walls of the outer openings in the vehicle width direction and their upper and lower corners (ridge portions) can be positioned in appropriate positions suitable for dispersing and transmitting impact loads.

[0016] The outer walls in the vehicle width direction of the inner openings adjacent to each other in the vehicle up-down direction may be set to be offset in the vehicle width direction when viewed from the front of the vehicle.

[0017] In this case, the outer walls of the inner openings adjacent to each other in the vertical direction of the vehicle are offset in the vehicle width direction, so that the outer walls of the inner openings in the vehicle width direction and their upper and lower corners (ridges) can be positioned in appropriate positions suitable for dispersing and transmitting impact loads.

[0018] The outer walls of the multiple inner openings in the vehicle width direction may be arranged such that the wall of the inner opening arranged below is positioned more inward in the vehicle width direction than the wall of the inner opening arranged above, and the approximately S-shaped cross-sectional portion may form a front wheel house that covers the inner side of the front wheels in the vehicle width direction.

[0019] In this case, the substantially S-shaped cross-section portion that constitutes the front wheelhouse has the lower inner opening wall positioned more inward in the vehicle width direction than the upper inner opening wall, which makes it easier to avoid interference between the load-receiving member and the front wheel inside the front wheelhouse compared to when a front side frame with a closed cross-section is placed in the same location.

[0020] The inner wall of the outer opening in the vehicle width direction may be inclined in the vehicle width direction from rear to front when viewed from above.

[0021] In this case, since the inner wall of the outer opening in the vehicle width direction is inclined in the vehicle width direction from the rear to the front, the inner wall of the outer opening in the vehicle width direction and its upper and lower corners (ridge portions) can be positioned at an appropriate angle suitable for dispersing and transmitting impact loads.

[0022] The wall of the outer opening on the inner side in the vehicle width direction may be inclined outward in the vehicle width direction from rear to front when viewed from above.

[0023] In this case, the upper and lower corners (ridge lines) of the outer opening can be positioned so that the front end of the vehicle faces outward in the vehicle width direction, so that when an impact load is input from diagonally in front of the vehicle, the impact load can be effectively absorbed by the upper and lower corners (ridge lines) of the outer opening.

[0024] The inner walls of the outer openings in the vehicle width direction and the outer walls of the inner openings in the vehicle width direction may be inclined at different angles from rear to front when viewed from above.

[0025] In this case, since the upper and lower corners (ridges) of the multiple outer openings and inner openings are inclined at different angles from rear to front, when an impact load is input from any direction to the front of the approximately S-shaped cross-section, the corners (ridges) of the multiple outer openings and inner openings oriented in different directions can efficiently absorb the moment acting on the approximately S-shaped cross-section. Therefore, when this configuration is adopted, irregular bending of the approximately S-shaped cross-section when an impact load is input can be suppressed, and the energy of the impact load can be efficiently absorbed.

[0026] The load-receiving member may be configured such that each constituent wall constituting the approximately S-shaped cross-sectional portion has an uneven portion that protrudes alternately on one side and the other side perpendicular to the surface in the fore-and-aft direction of the vehicle, and breakage-inducing portions are provided at multiple locations in the fore-and-aft direction of the vehicle on the uneven portion of each constituent wall.

[0027] In this case, when an impact load is applied from the front of the vehicle, the multiple locations of the concave and convex portions of each component wall can be deformed and crushed sequentially, starting from the fracture induction portion. Therefore, when this configuration is adopted, residual crushing when an impact load is applied can be suppressed and a sufficient energy absorption stroke can be secured.

[0028] A vehicle load-receiving member according to one aspect of the present invention has a substantially S-shaped cross-section in which one side opening and the other side opening are connected in a third direction. Therefore, when an impact load is applied from the first direction, the applied load is transmitted evenly across almost the entire area of ​​the substantially S-shaped cross-section, and the entire area of ​​the substantially S-shaped cross-section is deformed evenly. Therefore, when the vehicle load-receiving member according to this aspect is used, a wide range of the load-receiving member can be effectively used to absorb the energy of the impact load.

[0029] A vehicle front structure according to one aspect of the present invention includes a substantially S-shaped cross-section in which an inner opening and an outer opening are connected in the vehicle vertical direction. Therefore, when an impact load is applied from the front of the vehicle, the applied load is transmitted evenly across almost the entire area of ​​the substantially S-shaped cross-section, causing the entire area of ​​the substantially S-shaped cross-section to deform evenly. Therefore, when the vehicle front structure according to this aspect is adopted, a wide range of the load-receiving member can be effectively used to absorb the energy of the impact load.

[0030] 1 is a perspective view of a front part of a vehicle according to an embodiment; a perspective view of a front part of a vehicle in which some members of FIG. 1 are shown in virtual lines; a front view of a load-receiving member according to an embodiment as seen from the front side of the vehicle; a cross-sectional view of the load-receiving member according to an embodiment taken along line IV-IV of FIG. 3; a view of the load-receiving member according to an embodiment as seen from the arrow V of FIG. 4; a schematic longitudinal cross-sectional view of the load-receiving member according to an embodiment; a schematic side view of the load-receiving member according to an embodiment corresponding to the view of arrow VII of FIG. 6; a schematic bottom view of the load-receiving member according to an embodiment corresponding to the view of arrow VIII of FIG. 6; a view illustrating a cross-section (a) of the load-receiving member according to an embodiment taken along the first direction and the third direction, and a cross-section (b) of the load-receiving member according to an embodiment taken along the first direction and the second direction; cross-sectional views (a) to (c) sequentially showing the deformation behavior of the load-receiving member according to an embodiment when an impact load is input; a top view of the load-receiving member according to an embodiment.

[0031] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the following description, unless otherwise specified, the terms "front, rear, up, down, left, right" and "rear" refer to the front, rear, up, down, left, right and left of the vehicle 1. In addition, in the drawings, the arrow FR points forward of the vehicle 1, the arrow UP points upward of the vehicle 1, and the arrow LH points to the left side of the vehicle 1.

[0032] FIG. 1 is a perspective view of the front portion of a vehicle 1 according to this embodiment. FIG. 2 is a perspective view similar to FIG. 1 , showing some components (load-receiving members 20, described later) in phantom lines. Reference numeral 10 in FIGS. 1 and 2 denotes a pair of damper housings spaced apart on both the left and right sides of a front compartment 11 in front of the driver's seat. The damper housings 10 are cylindrical and have a top wall, and the top wall supports the upper portions of dampers (not shown) of the front suspension. The left and right damper housings 10 are connected to a base block 12 extending along the vehicle width direction. The base block 12 is joined to left and right vehicle body frameworks in front of the driver's seat. Support brackets 13 extend from the undersides of the left and right sides of the base block 12 to swingably support the corresponding left and right front wheels W. In this embodiment, the base block 12 and the left and right damper housings 10 form a suspension support structure 15.

[0033] A load-receiving member 20 extending substantially along the vehicle longitudinal direction is connected to the front side of each of the left and right damper housings 10. The left and right load-receiving members 20 are formed substantially symmetrically. The load-receiving members 20 are made of cast parts made of aluminum alloy.

[0034] The left and right side edges of a bumper beam 14 disposed at the front of the vehicle 1 are connected to the front surfaces of the left and right load-receiving members 20 near the bottom. The bumper beam 14 extends horizontally substantially along the vehicle width direction, and the rear surfaces (rear surfaces) of the left and right side edges are connected to the front ends of the corresponding load-receiving members 20. The vehicle front structure of this embodiment is mainly composed of a suspension support structure 15 and load-receiving members 20 connected to the bumper beam 14.

[0035] FIG. 3 is a front view of the load-receiving member 20 as seen from the front side of the vehicle, and FIG. 4 is a cross-sectional view of the load-receiving member 20 taken along line IV-IV in FIG. 3. As shown in these figures, the load-receiving member 20 includes a first open cross-sectional portion 21, which is a plate-shaped wall portion extending generally along the vehicle longitudinal direction and bent in a crank-like manner in the vertical and horizontal directions, and a second open cross-sectional portion 22, which is a plate-shaped wall portion extending generally along the vehicle longitudinal direction and bent in a crank-like manner in the vertical and horizontal directions, and which is similarly arranged. The second open cross-sectional portion 22 is positioned above the first open cross-sectional portion 21 and outboard in the vehicle width direction. The bent shapes of the first open cross-sectional portion 21 and the second open cross-sectional portion 22 may be generally L-shaped or channel-shaped, or may include a partially curved portion.

[0036] A plate-shaped load input wall 23 extending in a direction intersecting (substantially perpendicular to) the vehicle longitudinal direction is provided at the front end of the first open cross-sectional portion 21. The bumper beam 14 is fastened and fixed to the front surface of the load input wall 23. A plate-shaped lower load transmission wall 24 extending in a direction intersecting (substantially perpendicular to) the vehicle longitudinal direction is provided at the rear end of the first open cross-sectional portion 21. The rear surface of the lower load transmission wall 24 is fastened and fixed to the lower front surface of the side portion of the base block 12 (the front surface of a second load receiving wall 25 described later). The load input wall 23 is disposed at a portion of the front end of the first open cross-sectional portion 21 that overlaps at least the joint portion of the bumper beam 14 in the vertical direction. The load input wall 23 may be formed to straddle the front end of a connecting wall portion 28 (described later) above the first open cross-sectional portion 21.

[0037] Additionally, a plate-shaped upper load transmission wall 26 (load transmission wall) extending in a direction intersecting (substantially perpendicular to) the vehicle longitudinal direction is provided at the rear end of the second open cross-sectional portion 22. The rear surfaces of the upper load transmission walls 26 are fastened and fixed to the front surfaces of the corresponding left and right damper housings 10 (front surfaces of first load receiving walls 27, described below). The upper load transmission wall 26 (load transmission wall) is disposed at a portion of the rear end of the second open cross-sectional portion 22 that overlaps at least the joint portion (first load receiving wall 27) of the suspension support structure 15 in the up-down direction.

[0038] The lower first open cross-sectional portion 21 and the upper second open cross-sectional portion 22 are connected by a plate-shaped connecting wall portion 28. The connecting wall portion 28 continuously connects the first open cross-sectional portion 21, which is located below on the inner side in the vehicle width direction, to the second open cross-sectional portion 22, which is located above on the outer side in the vehicle width direction, in the front-to-rear direction of the vehicle. The second open cross-sectional portion 22 and the first open cross-sectional portion 21, together with the connecting wall portion 28, form part of a front wheel house that covers the inner side of the front wheels W in the vehicle width direction.

[0039] Here, the front surface of the upper region of the base block 12 that constitutes the suspension support structure 15 and the front surfaces of the left and right damper housings 10 are continuous flat surfaces that face the front side of the vehicle. A portion of these flat surfaces constitutes the front surface of the first load receiving wall 27 to which the upper load transmission wall 26 at the rear of the load receiving member 20 is joined in surface contact. The front surfaces of the lower sides of the left and right side portions of the base block 12 also have flat surfaces that face the front side of the vehicle. These flat surfaces constitute the front surface of the second load receiving wall 25 to which the lower load transmission wall 24 at the rear of the load receiving member 20 is joined in surface contact. The first load receiving wall 27 to which the upper load transmission wall 26 is joined and the second load receiving wall 25 to which the lower load transmission wall 24 is joined are arranged to be flush with each other and face the front side of the vehicle.

[0040] In this embodiment, the connecting wall portion 28 is formed by continuously bending a plate-like wall portion extending substantially along the vehicle longitudinal direction in a crank-like shape in the vertical and horizontal directions, similar to the first open cross-sectional portion 21 and the second open cross-sectional portion 22. In this embodiment, the connecting wall portion 28 also has an open cross-sectional shape that is open in a direction intersecting the vehicle longitudinal direction.

[0041] As shown in FIG. 4 , the second open cross-sectional portion 22, the connecting wall portion 28, and the first open cross-sectional portion 21 of the load-receiving member 20 are formed into a crank-like cross-sectional shape that is continuous from top to bottom. More specifically, the above-mentioned portions (22, 28, 21) of the load-receiving member 20 are connected in the vertical direction of the vehicle by an inner opening 29 (one side opening) that opens in a generally U-shaped manner on the inside of the vehicle width direction when viewed from the front of the vehicle, and an outer opening 30 (the other side opening) that opens in a generally U-shaped manner on the outside of the vehicle width direction when viewed from the front of the vehicle. These inner openings 29 and outer openings 30 are alternately arranged in the vertical direction of the vehicle. In other words, a plurality of generally S-shaped cross-sectional portions 31 formed by connecting the inner openings 29 and outer openings 30 are connected in the vertical direction of the vehicle.

[0042] As shown in FIG. 4 , the vehicle width directional inner walls 30wi of the outer openings 30 adjacent to each other in the vertical direction of the load receiving member 20 are arranged such that the lower inner wall 30wi is shifted more inward in the vehicle width direction than the upper inner wall 30wi when viewed from the vehicle front-rear direction. Similarly, the vehicle width directional outer walls 29wo of the inner openings 29 adjacent to each other in the vertical direction of the load receiving member 20 are arranged such that the lower outer wall 29wo is shifted more inward in the vehicle width direction than the upper outer wall 29wo when viewed from the vehicle front-rear direction. The surface of the load receiving member 20 facing outward in the vehicle width direction forms the inner surface of the front side of the front wheel house that accommodates the front wheels W. In this embodiment, the vehicle width directional outer wall 29wo of the inner openings 29 is shifted more inward in the vehicle width direction as it extends downward as described above, which makes it easy to prevent the front wheels W from interfering with the load receiving member 20 when the front wheels W are steered.

[0043] Figure 11 is a top view of the load-receiving member 20 in a partially modified form. The modified form shown in Figure 11 is that a notch 60 is provided in the front part of the second open cross-sectional portion 22. In the space secured by this notch 60, an on-vehicle part such as a headlight can be placed.

[0044] As shown in FIG. 11 , the vehicle width directional inner walls 30wi of the outer openings 30 adjacent to each other in the vertical direction of the load receiving member 20 and their upper and lower corners c (ridge lines) are inclined outward in the vehicle width direction from rear to front when viewed from above. Also, although not shown in FIG. 11 , the vehicle width directional outer walls 29wo of the inner openings 29 adjacent to each other in the vertical direction of the load receiving member 20 and their upper and lower corners c (ridge lines) are similarly inclined outward in the vehicle width direction from rear to front when viewed from above. However, the inclination angles of the vehicle width directional inner walls 30wi of the outer openings 30 and their upper and lower corners c (the angles at which they incline outward in the vehicle width direction from rear to front when viewed from above) are set to different angles for each of the outer openings 30 spaced apart in the vertical direction. Similarly, the inclination angles of the vehicle width directional outer walls 29wo of the inner openings 29 and their upper and lower corners c are set to different angles for each of the inner openings 29 spaced apart in the vertical direction.

[0045] Figure 5 is a view of the load-receiving member 20 as seen from the arrow V in Figure 4. As shown in Figures 4 and 5, the inner opening 29 and the outer opening 30 are each composed of two walls facing substantially horizontally and one wall facing substantially vertically. The inner opening 29 and the outer opening 30, which are arranged above and below, share one wall facing substantially horizontally. Hereinafter, the wall facing substantially vertically will be referred to as a first wall 33, and the wall facing substantially horizontally will be referred to as a second wall 34.

[0046] Here, the load-receiving member 20 can be considered as a plurality of substantially L-shaped curved wall elements, each consisting of a first wall 33 and a second wall 34, arranged in series. The first wall 33 and the second wall 34 constituting each curved wall element are provided with uneven portions that alternately protrude on one side and the other side in the direction perpendicular to the surface in the longitudinal direction of the vehicle. Hereinafter, the uneven portion formed on the first wall 33 will be referred to as a first uneven portion 35, and the uneven portion formed on the second wall 34 will be referred to as a second uneven portion 36. Note that, for convenience of illustration, the first uneven portion 35 and the second uneven portion 36 are omitted from FIG. 3 .

[0047] FIG. 6 is a longitudinal cross-sectional view of the load receiving member 20, showing a simplified schematic view of a portion of the load receiving member 20. FIG. 7 is a schematic side view of the load receiving member 20 corresponding to the view of arrow VII in FIG. 6 , and FIG. 8 is a schematic bottom view of the load receiving member 20 corresponding to the view of arrow VIII in FIG. 6 . FIG. 9 is a schematic view showing a cross section (a) of the load receiving member 20 taken along the first direction F and the third direction T, and a cross section (b) of the load receiving member 20 taken along the first direction F and the second direction S. Next, with reference to FIGS. 6 to 9 , the specific structure of the wall portion of the load receiving member 20, which mainly comprises a first wall 33 and a second wall 34, will be described. In the following description, the main input direction of the load to be absorbed is defined as the first direction F, one direction substantially perpendicular to (intersecting with) the first direction F is defined as the second direction S, and another direction substantially perpendicular to (intersecting with) the first direction F and the second direction S is defined as the third direction T.

[0048] The first wall 33 described above extends substantially along the first direction F and the second direction S, and the second wall 34 extends substantially along the first direction F and the third direction T. The first wall 33 and the second wall 34 form an open cross section that is open in a direction intersecting the first direction F.

[0049] As shown in FIG. 8 , the first uneven portion 35 of the first wall 33 described above is bent toward the first direction F so as to alternately protrude to one side and the other side in the third direction T when viewed from the second direction S. As shown in FIG. 7 , the second uneven portion 36 of the second wall 34 described above is bent toward the first direction F so as to alternately protrude to one side and the other side in the second direction S when viewed from the third direction T. That is, the first uneven portion 35 and the second uneven portion 36 are shaped so as to alternately protrude to one side and the other side in the plane-perpendicular direction toward the first direction F (the vehicle front-rear direction). Note that the "plane-perpendicular direction" refers to a direction substantially perpendicular to the outer surface of the first wall 33 for the first uneven portion 35, and a direction substantially perpendicular to the outer surface of the second wall 34 for the second uneven portion 36.

[0050] 8, the first uneven portion 35 of the first wall 33 has a first convex portion 37 that protrudes in a direction away from the second wall 34 and a first concave portion 38 that is recessed in a direction approaching the second direction S when viewed from the second direction S. As shown in FIG. 7, the second uneven portion 36 of the second wall 34 has a second convex portion 39 that protrudes in a direction away from the first wall 33 and a second concave portion 40 that is recessed in a direction approaching the first wall 33 when viewed from the third direction.

[0051] In the first wall 33, the most protruding portion of the first convex portion 37 and the most recessed portion of the first recess 38 are connected by a flat surface. As shown in Fig. 7 , the top t, which is the most protruding portion of the first convex portion 37, and the bottom b, which is the most recessed portion of the first recess 38, extend linearly along the second direction S. Similarly, in the second wall 34, the most protruding portion of the second convex portion 39 and the most recessed portion of the second recess 40 are connected by a flat surface. As shown in Fig. 8 , the top t of the second convex portion 39 and the bottom b of the second recess 40 extend linearly along the third direction T.

[0052] The first convex portion 37 on the first wall 33 and the second convex portion 39 on the second wall 34 are arranged at approximately the same position in the first direction F. Similarly, the first concave portion 38 on the first wall 33 and the second concave portion 40 on the second wall 34 are arranged at approximately the same position in the first direction F. Furthermore, at the corner c (ridge portion) where the first wall 33 and the second wall 34 are joined, as shown in FIG. 5 , convex-shaped portions 41 continuing from the first convex portion 37 and the second convex portion 39 and concave portions 42 continuing from the first concave portion 38 and the second concave portion 40 are arranged alternately along the first direction F.

[0053] The load-receiving member 20 has fracture inducing portions 44 at the most protruding portions of each first convex portion 37 of the first uneven portion 35 and at the most protruding portions of each second convex portion 39 of the second uneven portion 36. That is, the fracture inducing portions 44 are provided at a plurality of locations in the first direction of the first uneven portion 35 and the second uneven portion 36. The fracture inducing portions 44 have a smaller section modulus in the perpendicular direction than other portions. Specifically, the fracture inducing portions 44 provided in the first convex portion 37 are set to have a smaller section modulus in the third direction T than the first concave portion 38, and the fracture inducing portions 44 provided in the second convex portion 39 are set to have a smaller section modulus in the second direction S than the second concave portion 40. In the following, the portion of the first convex portion 37 with a small cross-sectional modulus in the third direction T may be referred to as the "first small cross-sectional modulus portion m1," and the portion of the second convex portion 39 with a small cross-sectional modulus in the second direction S may be referred to as the "second small cross-sectional modulus portion m2."

[0054] In this embodiment, the magnitude of the section modulus in the first uneven portion 35 and the second uneven portion 36 is changed by changing the thickness of the material in the target direction. Specifically, in the first uneven portion 35, as shown in FIG. 9A, the thickness t1 in the third direction T at the most protruding portion of the first convex portion 37 is set to be thinner (thinnest) than the thicknesses in the third direction T of the other portions. Also, in the second uneven portion 36, as shown in FIG. 9B, the thickness t1 in the second direction S at the most protruding portion of the second convex portion 39 is set to be thinner (thinnest) than the thicknesses in the second direction S of the other portions.

[0055] As shown in FIG. 9A , the first uneven portion 35 has a thickness t2 in the third direction T at the most recessed portion of the first recess 38 that is thicker (thickest) than the thicknesses in the third direction T of the remaining portions. Also, as shown in FIG. 9B , the second uneven portion 36 has a thickness t2 in the second direction S at the most recessed portion of the second recess 40 that is thicker (thickest) than the thicknesses in the second direction S of the remaining portions. Therefore, in the first uneven portion 35 and the second uneven portion 36, the most protruding portions of the convex portions (first convex portion 37, second convex portion 39) have the smallest section modulus, and the most recessed portions of the concave portions (first concave portion 38, second concave portion 40) have the largest section modulus. Therefore, in the first uneven portion 35 and the second uneven portion 36, the most protruding portions of the convex portions (first convex portion 37, second convex portion 39) have the lowest rigidity and strength. Therefore, when an impact load is applied, the most protruding portion of each convex portion (first convex portion 37, second convex portion 39) functions as the fracture inducing portion 44. Furthermore, the most recessed portion of each concave portion (first concave portion 38, second concave portion 40) has higher rigidity and strength than other portions, and therefore can smoothly transmit the input load and reaction force to the front and rear convex portions (first convex portion 37, second convex portion 39) when an impact load is applied. At the corner c between the first wall 33 and the second wall 34, the thickness of the top of the convex portion 41 is set to be the thinnest, and the thickness of the bottom of the concave portion 42 is set to be the thickest.

[0056] In this embodiment, the fracture inducing portions 44 (first small cross-sectional modulus portion m1, second small cross-sectional modulus portion m2) are provided at the most protruding portions of each of the first and second uneven portions 35, 36. However, the locations where the fracture inducing portions 44 (first small cross-sectional modulus portion m1, second small cross-sectional modulus portion m2) are provided are not limited to the most protruding portions of each of the first and second uneven portions 35, 36. The fracture inducing portions 44 (first small cross-sectional modulus portion m1, second small cross-sectional modulus portion m2) may be provided, for example, at portions of each of the first and second uneven portions 35, 36 that are not the most protruding portions of each of the first and second uneven portions 36, or at recesses (first recess 38, second recess 40). Furthermore, the means for reducing the cross-sectional modulus of the fracture inducing portions 44 is not limited to reducing the thickness. For example, it is also possible to provide a notch or a small hole in a portion of each of the first and second uneven portions 35, 36.

[0057] 9(b), the distance D1 in the first direction F between the most protruding portion of the first convex portion 37 and the most recessed portion of the first recess 38 in the first uneven portion 35 is set to be narrower than the dimension L1 in the second direction S at the most protruding portion of the first convex portion 37. Also, as shown in FIG. 9(a), the distance D2 in the first direction F between the most protruding portion of the second convex portion 39 and the most recessed portion of the second recess 40 in the second uneven portion 36 is set to be narrower than the dimension L2 in the third direction T at the most protruding portion of the second convex portion 39.

[0058] As shown in FIG. 9A , the opening angle α1 between two planes (two planes adjacent in the first direction F) sandwiching the apex of the first convex portion 37 of the first wall 33 (first concave-convex portion 35) is set to be an obtuse angle (90°<α1<180°). Similarly, the opening angle α2 between two planes (two planes adjacent in the first direction F) sandwiching the bottom of the first concave portion 38 of the first wall 33 (first concave-convex portion 35) is set to be an obtuse angle (90°<α2<180°). Furthermore, as shown in FIG. 9B , the opening angle α1 between two planes (two planes adjacent in the first direction F) sandwiching the apex of the second convex portion 39 of the second wall 34 (second concave-convex portion 36) is set to be an obtuse angle (90°<α1<180°). Similarly, the opening angle α2 between two planes (two planes adjacent in the first direction F) sandwiching the bottom of the second recess 40 of the second wall 34 (second uneven portion 36) is set to be an obtuse angle (90°<α2<180°). Note that the above openings α1 and α2 are preferably in the range of 120°<α1, α2<180°, and most preferably α1 and α2 are 150°.

[0059] Figure 10 is a cross-sectional view sequentially showing, in (a) to (c), the deformation behavior of the load-receiving member 20 when an impact load is applied. Note that Figure 10 only shows a portion of the first uneven portion 35 and the second uneven portion 36 of the load-receiving member 20. The deformation behavior of the load-receiving member 20 when an impact load is applied will be described below with reference to Figure 10.

[0060] 10( a), when an impact load F is input from the front to the front portion of the load-receiving member 20, the input load is first transmitted to the frontmost convex portions (first convex portion 37, second convex portion 39) of the first uneven portion 35 and the second uneven portion 36. At this time, stress acts on the fracture inducing portions 44 (first small section modulus portion m1, second small section modulus portion m2) at the apex of each convex portion (first convex portion 37, second convex portion 39), and each convex portion (first convex portion 37, second convex portion 39) bends (deforms) so as to be compressed in the fore-and-aft direction of the vehicle, and fracture begins at the fracture inducing portion 44 at the apex.

[0061] 10(b), the front portion of the foremost convex portion (first convex portion 37, second convex portion 39) is crushed, and the crushed fragments fall downward due to gravity. If the impact load F continues to act on the front portion of the load-receiving member 20, the load is transmitted to the next convex portion (first convex portion 37, second convex portion 39) of the first uneven portion 35 and the second uneven portion 36. At this time, thick recesses (first recess 38, second recess 40) are located between the fractured remains of the foremost convex portion (first convex portion 37, second convex portion 39) and the next convex portion (first convex portion 37, second convex portion 39). Therefore, the load is transmitted efficiently from the fractured remains of the foremost convex portion (first convex portion 37, second convex portion 39) to the next convex portion (first convex portion 37, second convex portion 39). In addition, the load acting on the next convex portion (first convex portion 37, second convex portion 39) is received by a thicker concave portion (first concave portion 38, second concave portion 40) located rearward of that convex portion (first convex portion 37, second convex portion 39).

[0062] When the load is concentrated on the top of the next convex portion (first convex portion 37, second convex portion 39) in this way, as shown in Figure 10(c), the next convex portion (first convex portion 37, second convex portion 39) bends (deforms) so as to be compressed in the fore-and-aft direction of the vehicle, and begins to break from the break induction portion 44 at the top. After this, the next convex portion (first convex portion 37, second convex portion 39) breaks and falls downward due to gravity.

[0063] Similarly, the fracture progresses from the top (fracture inducing portion 44) of each of the convex portions (first convex portion 37, second convex portion 39) toward the rear of the vehicle. As the deformation and fracture of the load-receiving member 20 progresses from the front to the rear in this manner, the impact load input during this time is absorbed. Furthermore, because the fracture of the load-receiving member 20 progresses from the front to the rear when absorbing the impact load, it is unlikely that any remaining crushed portions of the load-receiving member 20 will remain.

[0064] As described above, the load-receiving member 20 of this embodiment is configured to include a substantially S-shaped cross-sectional portion 31 formed by connecting, in the third direction T, one side opening (inner opening 29) that opens in a substantially U-shape on one side in the second direction S and the other side opening (outer opening 30) that opens in a substantially U-shape on the other side in the second direction S. Therefore, when an impact load is input from the first direction F, the input load is transmitted evenly to almost the entire area of ​​the substantially S-shaped cross-sectional portion 31, and the entire area of ​​the substantially S-shaped cross-sectional portion 31 can be deformed almost evenly. Therefore, when the load-receiving member 20 of this embodiment is employed, a wide range of the load-receiving member 20 can be effectively used to absorb the energy of the impact load.

[0065] The vehicle front structure of this embodiment includes a load-receiving member 20 to which a bumper beam 14 is connected at its front end and to which a suspension support structure 15 is connected at its rear end, the load-receiving member 20 including a substantially S-shaped cross-section 31. The substantially S-shaped cross-section 31 includes an inner opening 29 that opens in a substantially U-shape on the inner side in the vehicle width direction and an outer opening 30 that opens in a substantially U-shape on the outer side in the vehicle width direction, the inner opening 29 being connected in the vertical direction of the vehicle. Therefore, when an impact load is applied from the front of the vehicle, the input load is transmitted evenly to almost the entire area of ​​the substantially S-shaped cross-section 31, and the entire area of ​​the substantially S-shaped cross-section 31 can be deformed almost evenly. Therefore, when the vehicle front structure of this embodiment is adopted, a wide range of the load-receiving member 20 can be effectively used to absorb the energy of the impact load.

[0066] Furthermore, in the vehicle front structure of this embodiment, the load-receiving member 20 has a plurality of approximately S-shaped cross-sectional portions 31 connected in the vertical direction of the vehicle. Therefore, the plurality of approximately S-shaped cross-sectional portions 31 connected in the vertical direction can distribute and transmit the impact load in the vertical direction and the vehicle width direction. Furthermore, in this configuration, since the plurality of approximately S-shaped cross-sectional portions 31 are connected in the vertical direction of the vehicle, the shape can be changed relatively freely while ensuring the basic function of dispersing the input impact load over a wide range. Therefore, when this configuration is adopted, the degree of freedom in changing the design and specifications of the vehicle can be increased.

[0067] In addition, in the vehicle front structure of this embodiment, the vehicle width direction inner walls 30wi of the outer openings 30 adjacent to each other in the vertical direction of the vehicle are set to be offset in the vehicle width direction when viewed from the front of the vehicle. Therefore, the vehicle width direction inner walls 30wi of the outer openings 30 that form the approximately S-shaped cross-section 31 and its upper and lower corners c (ridge lines) can be positioned in appropriate positions suitable for dispersing and transmitting impact loads.

[0068] In addition, in the vehicle front structure of this embodiment, the vehicle width direction outer walls 29wo of the inner openings 29 adjacent to each other in the vertical direction of the vehicle are set to be offset in the vehicle width direction when viewed from the front of the vehicle. In this case, too, the vehicle width direction outer walls 29wo of the inner openings 29 and their upper and lower corners c (ridge lines) can be positioned in appropriate positions suitable for dispersing and transmitting impact loads.

[0069] Furthermore, in the vehicle front structure of this embodiment, the walls 29wo of the inner openings 29 arranged below each other are disposed more inward in the vehicle width direction than the walls 29wo of the inner openings 29 arranged above each other. The substantially S-shaped cross-sectional portion 31 forms a front wheel house that covers the inner sides of the front wheels W in the vehicle width direction. In this case, the walls 29wo of the inner openings 29 arranged below each other are disposed more inward in the vehicle width direction than the walls 29wo of the inner openings 29 arranged above each other. This makes it easier to avoid interference between the load-receiving member 20 and the front wheels W in the front wheel house than in the case where front side frames with closed cross sections are arranged in the same locations.

[0070] In addition, in the vehicle front structure of this embodiment, the inner wall 30wi of the outer opening 30 in the vehicle width direction is inclined in the vehicle width direction from rear to front when viewed from above, as shown in Fig. 11. This allows the inner wall 30wi of the outer opening 30 in the vehicle width direction and its upper and lower corners c (ridge lines) to be positioned at an appropriate angle suitable for dispersing and transmitting an impact load.

[0071] In particular, in the vehicle front structure of this embodiment, the inner wall 30wi of the outer opening 30 in the vehicle width direction is inclined outward in the vehicle width direction from rear to front when viewed from above. In this case, the upper and lower corners c (ridge lines) of the outer opening 30 can be arranged so that the front end of the vehicle faces outward in the vehicle width direction. Therefore, when an impact load is input diagonally from the front of the vehicle 1, the impact load can be appropriately absorbed by the upper and lower corners c (ridge lines) of the outer opening 30.

[0072] Furthermore, in the vehicle front structure of this embodiment, the inner walls 30wi of the multiple outer openings 30 in the vehicle width direction and the outer walls 29wo of the multiple inner openings 29 in the vehicle width direction are arranged so as to incline at different angles from rear to front when viewed from above. In this case, when an impact load is applied to the front of the approximately S-shaped cross-section 31 from any direction, the corners c (ridges) of the multiple outer openings 30 and the corners c (ridges) of the multiple inner openings 29, which are oriented in various directions, can efficiently absorb the moment acting on the approximately S-shaped cross-section 31. This increases the resistance to the moment acting on the approximately S-shaped cross-section 31. Therefore, when this configuration is adopted, irregular bending of the approximately S-shaped cross-section 31 is suppressed when an impact load is applied, making it possible to efficiently absorb the energy of the impact load.

[0073] Furthermore, in the vehicle front structure of this embodiment, each of the walls (first wall 33, second wall 34) constituting the approximately S-shaped cross-section portion 31 has an uneven portion that repeatedly protrudes alternately on one side and the other side in the direction perpendicular to the surface in the vehicle longitudinal direction, and fracture inducing portions 44 are provided at multiple locations in the vehicle longitudinal direction of the uneven portion of each of the walls. Therefore, when an impact load is input from the front of the vehicle, the multiple locations of the uneven portion of each of the walls can be sequentially deformed and fractured starting from the fracture inducing portions 44. Therefore, when this configuration is adopted, residual crushing upon input of an impact load can be suppressed, and a sufficient energy absorption stroke can be ensured.

[0074] The present invention is not limited to the above-described embodiment, and various design modifications are possible without departing from the spirit of the present invention. For example, in the above-described embodiment, the substantially S-shaped cross-sectional portion 31 is provided over the entire first open cross-sectional portion, the connecting wall portion, and the second open cross-sectional portion, but the substantially S-shaped cross-sectional portion 31 may be provided only in a part of these portions.

[0075] In the above embodiment, the load-receiving member 20 is disposed on the front surface of the damper housing 10 at the front of the vehicle, and is configured to receive an impact load from the front of the vehicle. However, the location of the load-receiving member 20 and the direction in which the load is received are not limited to this. The load-receiving member 20 may be disposed at a location other than the front of the vehicle 1, and the direction in which the load is received may be other directions, such as the vehicle width direction (for example, a direction in which an impact load input from the side of the vehicle is received) or the up-down direction (for example, a direction in which an impact load acting on the top surface of the front hood is received).

[0076] 14... Bumper beam 15... Suspension support structure 20... Load-receiving member 29... Inner opening (one side opening) 29wo... Vehicle width direction outer wall 30... Outer opening (other side opening) 30wi... Vehicle width direction inner wall 31... Approximately S-shaped cross-section portion 35... First uneven portion (uneven portion) 36... Second uneven portion (uneven portion) 44... Fracture inducing portion

Claims

1. When the main input direction of the load to be absorbed is defined as a first direction, one direction intersecting the first direction as a second direction, and another direction intersecting the first and second directions as a third direction, a load-receiving member for a vehicle characterized by having a substantially S-shaped cross section formed by connecting in the third direction a one-side opening that opens in a substantially U-shape on one side of the second direction as viewed from the first direction, and an other-side opening that opens in a substantially U-shape on the other side of the second direction as viewed from the first direction.

2. A vehicle front structure having a load-receiving member that extends approximately along the longitudinal direction of the vehicle, with the front end connected to a bumper beam and the rear end connected to a suspension support structure, wherein the load-receiving member has an approximately S-shaped cross section in which an inner opening that opens in a roughly U-shape on the inside in the vehicle width direction when viewed from the front of the vehicle and an outer opening that opens in a roughly U-shape on the outside in the vehicle width direction when viewed from the front of the vehicle are connected in the vertical direction of the vehicle.

3. The vehicle front structure according to claim 2, wherein the substantially S-shaped cross-section portion is a plurality of portions connected in the vertical direction of the vehicle.

4. A vehicle front structure as described in claim 3, characterized in that the inner walls in the vehicle width direction of the outer openings adjacent to each other in the vertical direction of the vehicle are offset in the vehicle width direction when viewed from the front of the vehicle.

5. A vehicle front structure as described in claim 3 or 4, characterized in that the outer walls of the inner openings adjacent to each other in the vertical direction of the vehicle are offset in the vehicle width direction when viewed from the front of the vehicle.

6. The vehicle front structure described in claim 5, characterized in that the walls on the outer sides of the multiple inner openings in the vehicle width direction are arranged more inward in the vehicle width direction than the walls of the inner openings arranged above, and the approximately S-shaped cross-sectional portion forms a front wheelhouse that covers the inside of the front wheels in the vehicle width direction.

7. A vehicle front structure according to claim 3, characterized in that the inner wall of the outer opening in the vehicle width direction is inclined in the vehicle width direction from rear to front when viewed from above.

8. A vehicle front structure according to claim 7, characterized in that the wall on the inner side in the vehicle width direction of the outer opening is inclined outward in the vehicle width direction from rear to front when viewed from above.

9. A vehicle front structure as described in claim 3, characterized in that each wall of the outer openings on the inner side in the vehicle width direction and each wall of the inner openings on the outer side in the vehicle width direction are inclined at different angles from rear to front when viewed from above.

10. The vehicle front structure described in claim 2, characterized in that each of the constituent walls constituting the approximately S-shaped cross-section of the load-receiving member has uneven portions that repeatedly protrude alternately on one side and the other in the direction perpendicular to the surface in the longitudinal direction of the vehicle, and that fracture-inducing portions are provided at multiple locations in the longitudinal direction of the vehicle at the uneven portions of each of the constituent walls.

Images