Vehicle front structure

Abstract

This vehicle front structure comprises a load-receiving member that extends substantially along the front-rear direction of a vehicle, has a front section joined with a bumper beam, and has a rear section joined to a suspension support structure. The load-receiving member comprises a first open cross-section part, a second open cross-section part, and a connection wall. In the first open cross-section part, an open cross section composed of at least two surfaces extends substantially along the vehicle front-rear direction, the front section is joined with the bumper beam, and the rear section is joined to the suspension support structure. In the second open cross-section part, an open cross section composed of at least two surfaces extends in the vehicle front-rear direction on the upper side of the first open cross-section part, and the rear section is joined to the suspension support structure. The connection wall connects the first open cross-section part and the second open cross-section part continuously in the vehicle front-rear direction.

Description

Vehicle front structure

[0001] The present invention relates 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 area of ​​the vehicle front for absorbing the energy of the impact load.

[0007] The problem to be solved is to enable a wide area of ​​the front of the vehicle 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 vehicle front structure according to one aspect of the present invention is a vehicle front structure comprising 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, wherein the load-receiving member comprises: a first open cross-sectional portion having an open cross-section formed of at least two sides 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; a second open cross-sectional portion having an open cross-section formed of at least two sides that extends in the fore-and-aft direction of the vehicle above the first open cross-sectional portion, and has a rear end that is connected to the suspension support structure; and a connecting wall portion that continuously connects the first open cross-sectional portion and the second open cross-sectional portion in the fore-and-aft direction of the vehicle.

[0009] With the above configuration, when an impact load is input from the front of the vehicle, the load is input to the lower first open cross-sectional portion through the bumper beam. A portion of the load input to the front of the first open cross-sectional portion is transmitted directly to the rear suspension support structure through the first open cross-sectional portion. Furthermore, another portion of the load input to the front of the first open cross-sectional portion is transmitted to the upper second open cross-sectional portion through the connecting wall portion. Since the connecting wall continuously connects the first open cross-sectional portion and the second open cross-sectional portion in the fore-and-aft direction of the vehicle, the load is transmitted in a dispersed manner over a wide area in the fore-and-aft direction of the second open cross-sectional portion. The load input to the second open cross-sectional portion is transmitted to the rear suspension support structure through the second open cross-sectional portion. Furthermore, when an impact load is input to the front of the second open cross-sectional portion from the front of the vehicle, a portion of the load is transmitted to the rear suspension support structure through the second open cross-sectional portion, and another portion of the load is transmitted to the rear suspension support structure through the connecting wall portion and the first open cross-sectional portion. In this configuration, the first open cross-sectional portion and the second open cross-sectional portion, which transmit an impact load from the front of the vehicle to the rear suspension support structure, are not closed cross-sectional, making it difficult for partial rigidity differences to occur across almost the entire area in the vertical direction of the vehicle. As a result, the load is transmitted approximately evenly across the entire areas of the first open cross-sectional portion, the connecting wall portion, and the second open cross-sectional portion. Therefore, when an impact load is input from the front of the vehicle, the entire areas of the first open cross-sectional portion, the connecting wall portion, and the second open cross-sectional portion deform approximately evenly, thereby efficiently absorbing the energy of the impact load.

[0010] The first open cross-sectional portion may be positioned more inward in the vehicle width direction than the second open cross-sectional portion, and the first open cross-sectional portion, the second open cross-sectional portion, and the connecting wall portion may form a front wheel house that covers the inner side of the front wheels in the vehicle width direction.

[0011] In this case, the first open cross-section portion, whose open cross-section extends in the fore-and-aft direction of the vehicle, is positioned more inward in the vehicle width direction than the upper second open cross-section portion, making it easier to avoid interference between the load-receiving member and the front wheels in the front wheel housing than when a front side frame with a closed cross-section is positioned in the same location.

[0012] A load input wall extending in a direction intersecting the longitudinal direction of the vehicle may be provided at least in the portion of the front end of the first open cross-section portion that overlaps in the vertical direction with the joint portion of the bumper beam, and a load transmission wall extending in a direction intersecting the longitudinal direction of the vehicle may be provided at least in the portion of the rear end of the second open cross-section portion that overlaps in the vertical direction with the joint portion of the suspension support structure.

[0013] In this case, when an impact load is input to the bumper beam from the front, the load is input to the first open cross-sectional portion through the load input wall disposed at the front end of the first open cross-sectional portion. Because the load input wall extends in a direction intersecting the vehicle longitudinal direction, the load can be transmitted over a wide area at the front end of the first open cross-sectional portion. The impact load input to the first open cross-sectional portion is transmitted to the second open cross-sectional portion above via the connecting wall, and then transmitted over a wide area of ​​the suspension support structure through the load transmission wall disposed at the rear end of the second open cross-sectional portion. Therefore, when this configuration is adopted, the input load can be transmitted to the suspension support structure by distributing it more evenly over a wide area of ​​the load-receiving member.

[0014] The suspension support structure may be provided with a first load receiving wall that extends in a direction intersecting the vehicle longitudinal direction and is joined to the load transmitting wall in surface contact therewith.

[0015] In this case, the impact load transmitted to the rear of the second open cross-sectional portion is transmitted over a wide area of ​​the suspension support structure through the surface contact portion between the load transmitting wall at the rear end of the second open cross-sectional portion and the first load receiving wall. Therefore, when this configuration is adopted, the rear of the second open cross-sectional portion is stably supported over a wide area, making it possible to distribute the load over a wider area of ​​the load receiving member.

[0016] The suspension support structure is provided with a second load-receiving wall extending in a direction intersecting the fore-and-aft direction of the vehicle and joined in face-to-face contact with the rear of the first open cross-sectional portion, and it is desirable that the first load-receiving wall and the second load-receiving wall be arranged flush with each other and facing forward of the vehicle.

[0017] In this case, the impact load distributed to the first open cross-sectional portion and the second open cross-sectional portion is received by the first load-receiving wall and the second load-receiving wall of the suspension support structure in a similar manner. Furthermore, because the first load-receiving wall and the second load-receiving wall are flush with each other and oriented toward the front of the vehicle, they can stably receive an impact input from the front of the vehicle at approximately the same time. Therefore, when this configuration is adopted, the deformation behavior of the load-receiving member can be more stabilized, enabling more efficient absorption of the energy of the impact load.

[0018] The load-receiving member may be provided with a member fastening portion that opens in the vehicle width direction, and a reinforcing rib extending in the vehicle vertical direction may be provided on at least one of the front and rear of the member fastening portion in the vehicle longitudinal direction, and the reinforcing rib may be arranged across at least two of the first open cross-sectional portion, the second open cross-sectional portion, and the connecting wall portion.

[0019] In this case, the member fastening portion provided on the load-receiving member is reinforced by the reinforcing rib on at least one of the front and rear sides in the vehicle longitudinal direction. This prevents deformation of a portion of the load-receiving member due to an external load input through the member fastening portion. Furthermore, because the reinforcing rib is disposed across at least two of the first open cross-sectional portion, the second open cross-sectional portion, and the connecting wall portion, it is possible to increase the bending rigidity of the load-receiving member in the vertical direction and the vehicle width direction.

[0020] The connecting wall portion may be configured to have 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.

[0021] In this case, the impact load input to the front of the first open cross-sectional portion or the second open cross-sectional portion can be dispersed and transmitted in the vertical and transverse directions by the approximately S-shaped cross-sectional portion of the connecting wall. In particular, the approximately S-shaped cross-sectional portion is bent in a wave-like manner in the vertical direction, which suppresses bending of the connecting wall in the vertical direction and allows for efficient dispersion of the load in the vertical and transverse directions. Furthermore, the approximately S-shaped cross-sectional portion of the connecting wall has corners (ridge lines) that extend along the fore-and-aft direction of the vehicle alternately arranged in the vertical direction on the inside and outside of the vehicle transverse direction, allowing for effective transmission of the load to the rear of the vehicle through these corners.

[0022] The connecting wall portion is preferably configured by a plurality of the substantially S-shaped cross-section portions connected in the vertical direction of the vehicle.

[0023] 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 of the connecting wall are connected in the vertical direction of the vehicle, the shape can be changed relatively freely while maintaining the basic function described above. Therefore, adopting this configuration allows for greater freedom in vehicle design and specification planning.

[0024] A notch for component placement may be provided in the front end region of the second open cross-sectional portion.

[0025] In this case, since the second open cross-section portion is composed of multiple surfaces that form an open cross-section, it is relatively easy to form a cutout portion, unlike a frame material with a closed cross-section, and therefore it is possible to optimally position the component using a cutout portion that is suited to the shape and size of the component to be placed.

[0026] Each of the constituent walls of the first open cross-sectional portion, the second open cross-sectional portion, and the connecting wall portion may have uneven portions that protrude alternately on one side and the other side perpendicular to the surface in the longitudinal direction of the vehicle, and breakage induction portions may be provided at multiple locations in the longitudinal direction of the vehicle on the uneven portions of each of the constituent walls.

[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] In a vehicle front structure according to one aspect of the present invention, the lower first open cross-sectional portion and the upper second open cross-sectional portion are continuously connected in the longitudinal direction of the vehicle by a connecting wall portion. Therefore, when an impact load is input from the front of the vehicle, the entire areas of the first open cross-sectional portion, the connecting wall portion, and the second open cross-sectional portion are substantially uniformly deformed. Therefore, when the vehicle front structure according to this aspect is employed, a wide area of ​​the vehicle front can be effectively used to absorb the energy of the impact load.

[0029] 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 imaginary 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 perspective view of the load receiving member according to an embodiment as seen from the outer side in the vehicle width direction; a cross-sectional view showing a first modified example of the load receiving member; a cross-sectional view showing a second modified example of the load receiving member. 10A and 10B are cross-sectional views showing a third modified example of the load receiving member, and a fourth modified example of the load receiving member.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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 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 30 that opens in a roughly U-shape on the outside in 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 roughly 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.

[0041] 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.

[0042] Furthermore, the vehicle width direction inner walls 30wi and the upper and lower corners c (ridges) thereof of the outer openings 30 adjacent to each other in the vertical direction of the load-receiving member 20 are inclined outward in the vehicle width direction from rear to front when viewed from above. However, the inclination angles of the vehicle width direction inner walls 30wi and the upper and lower corners c of the outer openings 30 (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 that are spaced apart in the vertical direction.

[0043] 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.

[0044] 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 .

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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."

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] 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°.

[0057] 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.

[0058] 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.

[0059] 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).

[0060] 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.

[0061] 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.

[0062] FIG. 11 is a perspective view of the load-receiving member 20 as viewed from the outside in the vehicle width direction. As shown in FIG. 11 , a member fastening portion 55 for fastening a suspension arm (not shown) is provided in a portion of the vehicle width outer wall 29wo of the first open cross-sectional portion 21 located in the lower region of the load-receiving member 20. The member fastening portion 55 is provided on the vehicle width outer wall 29wo of the first open cross-sectional portion 21 so as to open outward in the vehicle width direction. Note that although the member fastening portion 55 in this embodiment is for fastening a suspension arm, the member fastening portion 55 may be for fastening a member other than a suspension arm. The member fastening portion 55 may be for fastening, for example, a subframe or an auxiliary device.

[0063] A pair of plate-shaped reinforcing ribs 56 extending in a direction substantially perpendicular to (intersecting with) the vehicle longitudinal direction are provided at the front and rear positions of the member fastening portion 55 of the load-receiving member 20. These reinforcing ribs 56 are provided at the front and rear positions of the member fastening portion 55 so as to straddle the first open cross-sectional portion 21 and the connecting wall portion 28 above it. The pair of reinforcing ribs 56 are formed as an integrally cast part together with the first open cross-sectional portion 21 and the connecting wall portion 28.

[0064] In the present embodiment, a pair of reinforcing ribs 56 are formed across the first open cross-sectional portion 21 and the connecting wall portion 28. However, the reinforcing ribs 56 may also be formed across the second open cross-sectional portion 22 in addition to the first open cross-sectional portion 21 and the connecting wall portion 28. Depending on the shape of the load-receiving member 20, the reinforcing ribs 56 may also be formed across the first open cross-sectional portion 21 and the second open cross-sectional portion 22. The member fastening portion 55 may also be provided in the second open cross-sectional portion 22. In this case, the reinforcing ribs 56 may be provided across the second open cross-sectional portion 22 and at least one of the connecting wall portion 28 and the first open cross-sectional portion 21. Furthermore, in the present embodiment, a pair of reinforcing ribs 56 are provided at the front and rear of the member fastening portion 55. However, the reinforcing ribs 56 may also be provided at only one of the front and rear of the member fastening portion 55.

[0065] The load-receiving member 20 shown in FIG. 11 has a slightly different shape from that shown in FIGS. 1 and 2. A modified embodiment is also shown in FIG. 11. Specifically, the load-receiving member 20 shown in FIG. 11 has a cutout 60 for component placement in the front end region of the second open cross-sectional portion 22. The space provided by the cutout 60 can accommodate on-vehicle components such as headlights. The cutout 60 may also be used to adjust the amount of overlap with the fastening portion of the bumper beam 14. In this case, adjusting the amount of overlap with the fastening portion of the bumper beam 14 makes it possible to change the direction of transmission of the input load from the bumper beam 14.

[0066] As described above, the vehicle front structure of this embodiment includes the first open cross-sectional portion 21 extending substantially along the vehicle longitudinal direction, the second open cross-sectional portion 22 extending substantially along the vehicle longitudinal direction above the first open cross-sectional portion 21, and the connecting wall portion 28 continuously connecting the first open cross-sectional portion 21 and the second open cross-sectional portion 22 in the vehicle longitudinal direction. In this configuration, the first open cross-sectional portion 21 and the second open cross-sectional portion 22, which transmit impact loads from the vehicle front to the rear suspension support structure 15, are not closed cross-sectional, making it difficult for partial rigidity differences to occur over almost the entire area in the vehicle vertical direction. Therefore, the load can be transmitted substantially uniformly over the entire areas of the first open cross-sectional portion 21, the connecting wall portion 28, and the second open cross-sectional portion 22. Therefore, when an impact load is input from the front of the vehicle, the entire areas of the first open cross-sectional portion 21, the connecting wall portion 28, and the second open cross-sectional portion 22 deform substantially uniformly, thereby efficiently absorbing the energy of the impact load. Therefore, when the vehicle front structure of this embodiment is adopted, a wide area of ​​the vehicle front can be effectively used to absorb the energy of the impact load. This eliminates the need to make the front-to-rear length of the load-receiving member 20 longer than necessary, which also increases the degree of freedom in changing the design and specifications of the vehicle front.

[0067] Furthermore, in the vehicle front structure of this embodiment, the first open cross-sectional portion 21 is disposed more inward in the vehicle width direction than the second open cross-sectional portion 22, and the first open cross-sectional portion 21, the second open cross-sectional portion 22, and the connecting wall portion 28 form a front wheel house that covers the inside of the front wheel W in the vehicle width direction. With the above configuration, the first open cross-sectional portion 21, whose open cross-section extends in the fore-and-aft direction of the vehicle, is disposed more inward in the vehicle width direction than the upper second open cross-sectional portion 22. Therefore, when this configuration is adopted, it is easier to avoid interference between the load-receiving member 20 and the front wheel W in the front wheel house, compared to when a front side frame with a closed cross-section is disposed in the same location.

[0068] Furthermore, in the vehicle front structure of this embodiment, a load input wall 23 extending in a direction intersecting the vehicle longitudinal direction is provided at the front end of the first open cross-sectional portion 21, and an upper load transmission wall 26 (load transmission wall) extending in a direction intersecting the vehicle longitudinal direction is provided at the rear end of the second open cross-sectional portion 22. Therefore, when an impact load is input to the bumper beam 14 from the front, the load is input to the first open cross-sectional portion 21 through the wide surface of the load input wall 23 and is further transmitted to the suspension support structure 15 through the wide surface of the upper load transmission wall 26 at the rear of the first open cross-sectional portion 21. Therefore, when this configuration is adopted, when an impact load is input, the input load can be transmitted to the suspension support structure 15 by dispersing it more evenly over a wide area of ​​the load-receiving member 20.

[0069] Furthermore, in the vehicle front structure of this embodiment, the suspension support structure 15 is provided with a first load receiving wall 27, which extends in a direction intersecting the vehicle fore-and-aft direction and is joined in surface contact with the upper load transmission wall 26 of the second open cross-sectional portion 22. Therefore, an impact load transmitted to the rear of the second open cross-sectional portion 22 is transmitted over a wide area of ​​the suspension support structure 15 through the surface contact portion between the upper load transmission wall 26 at the rear end of the second open cross-sectional portion and the first load receiving wall 27. Therefore, when this configuration is adopted, the rear of the second open cross-sectional portion 22 is stably supported over a wide area, making it possible to distribute the load over a wider area of ​​the load-receiving member 20.

[0070] In the vehicle front structure of this embodiment, the suspension support structure 15 is provided with a second load receiving wall 25. The second load receiving wall 25 extends in a direction intersecting the vehicle longitudinal direction and is joined to the rear portion of the first open cross-sectional portion 21 in surface contact. The first load receiving wall 27 and the second load receiving wall 25 are flush with each other and oriented toward the front of the vehicle. Therefore, in this configuration, the impact load distributed to the first open cross-sectional portion 21 and the second open cross-sectional portion 22 can be received by the first load receiving wall 27 and the second load receiving wall 25 of the suspension support structure 15 in a similar surface-to-surface manner. Furthermore, in this configuration, the first load receiving wall 27 and the second load receiving wall 25 are flush with each other and oriented toward the front of the vehicle, so that an impact input from the front of the vehicle can be stably received at approximately the same time. Therefore, when this configuration is adopted, the deformation behavior of the load receiving member 20 can be more stabilized, and the energy of the impact load can be more efficiently absorbed.

[0071] Furthermore, in the vehicle front structure of this embodiment, a reinforcing rib 56 is provided at least on either the front or rear of the member fastening portion 55 formed on the load-receiving member 20 in the vehicle longitudinal direction, and the reinforcing rib 56 is arranged across at least two of the first open cross-sectional portion 21, the second open cross-sectional portion 22, and the connecting wall portion 28. This makes it possible to prevent deformation of a portion of the load-receiving member 20 due to a load input from the outside through the member fastening portion 55. Furthermore, because the reinforcing rib 56 is arranged across at least two of the first open cross-sectional portion 21, the second open cross-sectional portion 22, and the connecting wall portion 28, it is possible to increase the bending rigidity of the load-receiving member 20 in the up-down direction and the vehicle width direction.

[0072] In the vehicle front structure of this embodiment, the connecting wall 28 is configured to have a substantially S-shaped cross-section 31 that connects the inner opening 29 and the outer opening 30 in the vehicle up-down direction. Therefore, the substantially S-shaped cross-section 31 of the connecting wall 28 can distribute and transmit an impact load input to the front of the first open cross-section 21 or the second open cross-section 22 in the up-down direction and the vehicle width direction. Furthermore, the substantially S-shaped cross-section 31 of the connecting wall 28 is bent in a wavy manner in the vehicle width direction toward the up-down direction, thereby suppressing bending of the connecting wall 28 in the up-down direction and efficiently dispersing the load in the up-down direction and the vehicle width direction. Furthermore, the substantially S-shaped cross-section 31 of the connecting wall 28 has corners (ridge lines) that are alternately arranged in the up-down direction on the inside and outside of the vehicle width direction along the vehicle fore-and-aft direction, allowing the load to be effectively transmitted to the rear of the vehicle through these corners.

[0073] Furthermore, in the vehicle front structure of this embodiment, the connecting wall 28 has a plurality of generally S-shaped cross-sectional portions 31 connected in the vertical direction of the vehicle, so that the impact load input to the first open cross-sectional portion 21 or the second open cross-sectional portion 22 can be efficiently dispersed and transmitted in the vertical direction and the width direction of the vehicle. Furthermore, this configuration allows for relatively free changes in shape while maintaining this basic function. Therefore, when this configuration is adopted, it becomes possible to increase the degree of freedom in vehicle design and specification design.

[0074] 11 , when a cutout 60 for component placement is provided in the front end region of the second open cross-sectional portion 22, the component can be placed in an appropriate position using the cutout 60 that is suited to the shape and size of the component to be placed. In this case, the second open cross-sectional portion 22 is made up of multiple surfaces that form an open cross-section, so that the cutout 60 can be formed relatively easily, unlike a frame material with a closed cross-section.

[0075] Furthermore, in the vehicle front structure of this embodiment, each of the constituent walls of the first open cross-sectional portion 21, the second open cross-sectional portion 22, and the connecting wall portion 28 has a structure in which the first uneven portion 35, the second uneven portion 36 alternately protrude in the vehicle longitudinal direction. Furthermore, the uneven portion of each constituent wall is provided with fracture inducing portions 44 at multiple locations in the vehicle longitudinal direction. Therefore, when an impact load is applied from the front of the vehicle, the multiple locations of the uneven portion of each constituent wall can be sequentially deformed and fractured, starting from the fracture inducing portions 44. Therefore, when this configuration is adopted, residual crushing of the load-receiving member 20 upon application of an impact load can be suppressed, and a sufficient energy absorption stroke can be ensured.

[0076] <Modifications> In the above-described embodiment, the first open cross-sectional portion 21, the connecting wall portion 28, and the second open cross-sectional portion 22 of the load-receiving member 20 are configured by a plurality of continuous, approximately S-shaped cross-sectional portions 31, but the cross-sectional shape of the load-receiving member is not limited to this. The cross-sectional shape of the load-receiving member may be, for example, a shape like each of the modified examples shown in Figures 12 to 15.

[0077] 12 is a diagram showing a cross section of a load-receiving member 120 of a first modified example taken perpendicular to the vehicle longitudinal direction. In this first modified example, the first open cross-sectional portion 121 has a horizontal wall 121a connected to the lower end of the connecting wall portion 128 and a vertical wall 121b extending downward from the extended end of the horizontal wall 121a. The second open cross-sectional portion 122 has a vertical wall 122a connected to the upper end of the connecting wall portion 128 and a horizontal wall 122b extending substantially horizontally from the upper end of the vertical wall 122a. The first open cross-sectional portion 121 and the second open cross-sectional portion 122 are formed with an L-shaped cross section that is open downward and outward in the vehicle width direction. The connecting wall portion 128 is formed by a flat wall that is inclined so as to linearly connect the first open cross-sectional portion 121 and the second open cross-sectional portion 122.

[0078] 13 is a diagram showing a cross section perpendicular to the vehicle longitudinal direction of a load-receiving member 220 of a second modified example. In this second modified example, the first open cross-sectional portion 221 is formed with a generally U-shaped cross section that opens in the vehicle width direction, and the second open cross-sectional portion 222 is formed with a generally U-shaped cross section that opens downward. The connecting wall portion 228 is formed by a flat wall that is inclined so as to linearly connect the first open cross-sectional portion 221 and the second open cross-sectional portion 222.

[0079] 14 is a diagram showing a cross section of a load-receiving member 320 of a third modified example taken perpendicular to the vehicle longitudinal direction. In this third modified example, the first open cross-sectional portion 321 has a vertical wall 321a connected to the lower end of the connecting wall portion 328 and a horizontal wall 321b extending substantially horizontally from the lower end of the vertical wall 321a outward in the vehicle width direction. The second open cross-sectional portion 322 has a horizontal wall 322a connected to the upper end of the connecting wall portion 328 and a vertical wall 322b extending upward from the extending end of the horizontal wall 322a. The first open cross-sectional portion 321 and the second open cross-sectional portion 322 are formed with an L-shaped cross section that is open upward and outward in the vehicle width direction. The connecting wall portion 328 is formed by a flat wall that is inclined so as to linearly connect the first open cross-sectional portion 321 and the second open cross-sectional portion 322.

[0080] 15 is a diagram showing a cross section perpendicular to the vehicle longitudinal direction of a load receiving member 420 of a fourth modified example. In this load receiving member 420 of the fourth modified example, the first open cross-sectional portion 421 and the second open cross-sectional portion 422 have a generally L-shaped cross section that is open downward and outward in the vehicle width direction, as in the first modified example. The connecting wall portion 428 has a shape in which a plurality of generally U-shaped lower openings 71 and upper openings are alternately connected. The lower end of the connecting wall portion 428 is connected to the first open cross-sectional portion 421, and the upper end of the connecting wall portion 428 is connected to the second open cross-sectional portion 422.

[0081] In each of these modified examples, the lower first open cross-sectional portion and the upper second open cross-sectional portion are continuously connected in the vehicle longitudinal direction by the connecting wall portion, and therefore, when an impact load is input, the first open cross-sectional portion, the connecting wall portion, and the second open cross-sectional portion are deformed substantially uniformly throughout, as in the above-described embodiment, thereby efficiently absorbing the energy of the impact load.

[0082] 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.

[0083] DESCRIPTION OF SYMBOLS 14... Bumper beam 15... Suspension support structure 20, 120, 220, 320, 420... Load-receiving member 21, 121, 221, 321, 421... First open cross-sectional portion 22, 122, 222, 322, 422... Second open cross-sectional portion 23... Load input wall 25... Second load-receiving wall 26... Upper load transmission wall (load transmission wall) 27... First load-receiving wall 28, 128, 228, 328, 428... Connecting wall portion 29... Inner opening 30... Outer opening 31... Approximately S-shaped cross-sectional portion 35... First uneven portion (uneven portion) 36... Second uneven portion (uneven portion) 44... Fracture inducing portion 55... Member fastening portion 56... Reinforcing rib 60... Notch portion

Claims

1. A vehicle front structure comprising a load-receiving member that extends generally in the longitudinal direction of the vehicle, has a front portion connected to a bumper beam, and a rear portion connected to a suspension support structure, wherein the load-receiving member comprises: a first open cross-sectional portion having an open cross-section made up of at least two sides that extends generally in the longitudinal direction of the vehicle, has a front portion connected to the bumper beam, and a rear portion connected to the suspension support structure; a second open cross-sectional portion having an open cross-section made up of at least two sides that extends in the longitudinal direction of the vehicle above the first open cross-sectional portion, and has a rear portion connected to the suspension support structure; and a connecting wall portion that continuously connects the first open cross-sectional portion and the second open cross-sectional portion in the longitudinal direction of the vehicle.

2. The vehicle front structure described in claim 1, characterized in that the first open cross-sectional portion is positioned more inward in the vehicle width direction than the second open cross-sectional portion, and the first open cross-sectional portion, the second open cross-sectional portion, and the connecting wall portion form a front wheel house that covers the inside of the front wheels in the vehicle width direction.

3. A vehicle front structure as described in claim 1, characterized in that a load input wall extending in a direction intersecting the longitudinal direction of the vehicle is provided at least in the portion of the front end of the first open cross-section section that overlaps in the vertical direction with the joint of the bumper beam, and a load transmission wall extending in a direction intersecting the longitudinal direction of the vehicle is provided at least in the portion of the rear end of the second open cross-section section that overlaps in the vertical direction with the joint of the suspension support structure.

4. A vehicle front structure as described in claim 3, characterized in that the suspension support structure is provided with a first load receiving wall that extends in a direction intersecting the vehicle's fore-and-aft direction and is joined in face contact with the load transmitting wall.

5. A vehicle front structure as described in claim 4, characterized in that the suspension support structure is provided with a second load-receiving wall that extends in a direction intersecting the vehicle's fore-and-aft direction and is joined in face-to-face contact with the rear of the first open cross-sectional portion, and the first load-receiving wall and the second load-receiving wall are arranged flush with each other and oriented toward the front of the vehicle.

6. The vehicle front structure described in claim 1, characterized in that the load-receiving member is provided with a member fastening portion that opens in the vehicle width direction, and a reinforcing rib that extends in the vehicle up-down direction is provided on at least one of the front and rear of the member fastening portion in the vehicle longitudinal direction, and the reinforcing rib is arranged across at least two of the first open cross-sectional portion, the second open cross-sectional portion, and the connecting wall portion.

7. A vehicle front structure as described in claim 1 or 2, characterized in that the connecting wall portion has 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, connected in the vertical direction of the vehicle.

8. The vehicle front structure according to claim 7, wherein the connecting wall portion has a plurality of substantially S-shaped cross-section portions connected in the vertical direction of the vehicle.

9. The vehicle front structure according to claim 1, wherein a notch for component placement is provided in the front end region of the second open cross-sectional portion.

10. The vehicle front structure described in claim 1, characterized in that each of the constituent walls of the first open cross-sectional portion, the second open cross-sectional portion, and the connecting wall portion has uneven portions that protrude alternately on one side and the other in the direction perpendicular to the surface in the longitudinal direction of the vehicle, and that breakage induction portions are provided at multiple locations in the longitudinal direction of the vehicle in the uneven portions of each of the constituent walls.

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