Vehicle front body structure

Abstract

To make it possible to absorb energy of impact load when a vehicle undergoes a full wrap collision or an offset collision.SOLUTION: A front part vehicle structure of vehicle comprises: a front side frame 1 which is provided on each of left and right sides of a vehicle, and extends in a vehicle longitudinal direction; and a bumper beam 7 which is provided on a vehicle front side with respect to each front side frame, and has a ramp 71 which extends to a vehicle width direction outer side at both end parts in a vehicle width direction, and inclines toward the rear of the vehicle. A crash can 5, which extends toward the front of the vehicle and inclines to the vehicle width direction outer side, is provided at a front end part of each front side frame. The front end part of each crash can is connected to each ramp of the bumper beam. A fragile part, which has a low strength against an impact load inputted to the bumper beam, is provided on a vehicle width direction inner side of each crash can.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a front body structure of a vehicle. [Background technology]

[0002] Generally, a crash can is provided at the front of a vehicle to absorb the energy of a collision load when the vehicle collides. The crash can is provided at the front end of each of the front side frames that are arranged on both the left and right sides of the front of the vehicle and extend in the front-rear direction of the vehicle. The front end of the crash can is connected to a bumper beam that extends in the vehicle width direction. Therefore, when a collision load is input to the bumper beam, the collision load is input to the crash can via the bumper beam. As a result, the crash can is crushed and deformed, and the energy of the collision load is absorbed by the crash can.

[0003] Conventionally, there is known a crash can that extends straight in the longitudinal direction of the vehicle coaxially with the front side frame, as described in Patent Document 1. When a collision load is input to the bumper beam, the crash can is axially compressed to absorb the energy of the collision load. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2018-144578 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the vehicle front body structure described in Patent Document 1, the crash can is arranged coaxially with the front side frame and extends straight in the vehicle front-rear direction. In addition, both ends in the vehicle width direction of the bumper beam provided at the front end of the crash can extend outward in the vehicle width direction and are inclined toward the rear of the vehicle.

[0006] Therefore, when a vehicle has a collision with a low offset rate, such as a small overlap collision or a full overlap collision, the crash can is crushed from the front end, and the energy of the collision load is sufficiently absorbed. On the other hand, when a vehicle has a collision with a high offset rate, a so-called offset collision, a collision load having a component in a direction perpendicular to the inclined portion of the bumper beam (if the inclined portion is curved, the direction perpendicular to the tangent, i.e., the normal direction) is input to the crash can. As a result, the crash can is subjected to a collision load in a direction that bends the crash can, which may cause the crash can to buckle. If the crash can buckles, it cannot sufficiently absorb the energy of the collision load.

[0007] The present invention has been made in consideration of the above-mentioned points, and an object of the present invention is to make it possible to absorb the energy of a collision load in a full-overlap collision and an offset collision. [Means for solving the problem]

[0008] In order to achieve the above object, the crash can is disposed so as to extend toward the front of the vehicle and incline outward in the vehicle width direction, and a weak portion is provided on the inner side of the crash can in the vehicle width direction.

[0009] Specifically, the front body structure of the vehicle disclosed herein comprises: A front body structure of a vehicle including front side frames extending in a front-rear direction of the vehicle provided on each of the left and right sides of the vehicle, and a bumper beam provided forward of each of the front side frames and having inclined portions extending outward in the vehicle width direction at both ends in the vehicle width direction and inclined toward the rear of the vehicle, A crash can is provided at a front end of each of the front side frames, the crash can extending toward the front of the vehicle and inclining outward in the vehicle width direction, A front end portion of each of the crash cans is connected to each of the inclined portions of the bumper beam, A weak portion having a reduced strength against a collision load from the front of the vehicle is provided on the inner side of each of the crash cans in the vehicle width direction. 、 A suspension housing is connected to a middle portion of each of the front side frames in the vehicle front-rear direction, an outer weakened portion having a reduced strength against a collision load from the front of the vehicle is provided on an outer side of each of the front side frames in the vehicle width direction, the outer weakened portion being located forward of the suspension housing; an inner weakened portion having a reduced strength against a collision load from the front of the vehicle is provided on an inner side in the vehicle width direction of each of the front side frames, the inner weakened portion being located forward of the suspension housing; The outer weakened portion of each of the front side frames has a strength greater than that of the inner weakened portion. It is characterized by:

[0010] According to this front body structure of the vehicle, when the vehicle undergoes an offset collision, since the bumper beam has inclined portions at both ends in the vehicle width direction, a collision load having a component in a direction perpendicular to the inclined portions is input to the crash can via the inclined portions of the bumper beam.

[0011] The crash can is inclined in a direction perpendicular to the inclined portion of the bumper beam with respect to the vehicle longitudinal direction. Therefore, when a collision load due to an offset collision is input to the crash can through the inclined portion of the bumper beam, the load component in the axial direction of the crash can becomes large. This prevents the crash can from being bent inward in the vehicle width direction by the collision load of the offset collision, making the crash can more likely to be crushed and deformed.

[0012] However, if the axial direction of the crash can is simply tilted so that it approaches a direction perpendicular to the inclined portion of the bumper beam, the load input in the axial direction of the crash can is greater on the outer side of the crash can in the vehicle width direction than on the inner side in the vehicle width direction. Therefore, while the outer side of the crash can is more likely to be plastically distorted in the axial direction and works to absorb the collision energy, the inner side in the vehicle width direction is less likely to be plastically distorted. Therefore, a weak portion is provided on the inner side of the crash can in the vehicle width direction so that the inner side in the vehicle width direction also undergoes plastic distortion in the same way as the outer side in the vehicle width direction, thereby improving the absorption of collision energy.

[0013] Next, in the event of a full-wrap collision, a collision load is input to the bumper beam from the front of the vehicle. This collision load is input to the crash can via the bumper beam. As described above, the crash can is inclined in consideration of the absorption of collision energy in the case of an offset collision. For this reason, the inclination of the crash can makes it more likely to collapse outward from its base in the event of a full-wrap collision. Therefore, by providing a weak portion on the inside of the crash can and making it easier for plastic distortion to occur on the inner surface side than on the outer surface side, the outward collapse of the crash can is suppressed, and the crash can is crushed and deformed in the event of a full-wrap collision, thereby improving the absorption of collision energy.

[0014] As described above, the energy of the collision load input to the bumper beam is efficiently absorbed by the crash cans regardless of whether the collision is an offset collision or a full-wrap collision. When a vehicle has an offset collision, a collision load perpendicular to the inclined portion of the bumper beam is input to the crash can. This applies a force bending the crash can inward in the vehicle width direction, and also applies a force bending the front side frame inward in the vehicle width direction. When the front side frame is bent, the outer side of the front side frame in the vehicle width direction is the tension side, and the inner side in the vehicle width direction is the compression side. For this reason, the strength of the outer weak part of the front side frame is made higher than that of the inner weak part, that is, the strength of the tension side of the front side frame is made higher than that of the compression side, thereby suppressing the bending deformation of the front side frame due to this moment. Also, if the strength of the outer side of the front side frame in the vehicle width direction is only to be made higher than that of the inner side in the vehicle width direction, it is sufficient to only provide the inner weak part in the front side frame. However, by providing the outer weak part on the vehicle front side of the suspension housing of the front side frame, the strength of the rear side of the front side frame is higher than the strength of the front side of the front side frame. Therefore, when a collision load is input to the front side frame due to a vehicle collision, the front side frame is crushed and deformed successively from the front of the vehicle toward the rear of the vehicle.

[0015] In one embodiment, the cross-sectional outline of each of the crash cans at the rear end portion and the cross-sectional outline of each of the front side frames at the front end portion have substantially the same shape.

[0016] In this way, the rear end of the crash can can be firmly supported by the front end of the front side frame, which prevents the crash can from being displaced in an unintended direction, such as by buckling, due to a collision load, and makes the crash can more likely to be crushed and deformed.

[0017] In one embodiment, each of the crash cans comprises: A side portion facing the inside in the vehicle width direction; An upper surface portion facing upward of the vehicle; A lower surface portion facing downward toward the vehicle, The weakened portion is characterized in that it is formed by a ridge notch that cuts out at least one of the ridges formed by the side portion and the upper surface portion and the lower surface portion.

[0018] In this way, the ridge line formed by the side surface portion and the upper surface portion and the ridge line formed by the side surface portion and the lower surface portion The weakened portion can be formed in each of the crash cans by the simple method of forming a notch in at least one of the crash cans.

[0019] In one embodiment, a horizontal rib extending in the front-rear direction of the vehicle is formed inside each of the crash cans, a side notch that opens toward the inside in the vehicle width direction so that a side portion of the crash can on the inside in the vehicle width direction and the horizontal rib are partially separated from each other, In this way, the horizontal rib makes it easier to design the crash can's strength against a load collision in the vehicle's fore-and-aft direction to a strength suitable for absorbing collision energy. On the other hand, by partially separating the horizontal rib from the inside in the vehicle width direction by the side notch, the strength against a load collision can be partially reduced. This allows the side notch to function as a weak part. Therefore, a weak part can be formed in each crash can by the simple method of forming an opening on the inside in the vehicle width direction of the crash can.

[0024] In one embodiment, each of the front side frames is provided on both side surfaces in the vehicle width direction with a longitudinal concave-convex bead extending in the vehicle longitudinal direction, The longitudinal concave and convex bead provided on the vehicle width direction outer side of each of the front side frames is formed with an outer bead width expansion portion as the outer weak portion obtained by partially increasing the bead width, The longitudinal concave-convex bead provided on the vehicle width direction inner side of each of the front side frames is formed with an inner bead width expansion portion as the inner weak portion by partially increasing the bead width, The outer bead width enlarged portion of each of the front side frames has a bead width smaller than that of the inner bead width enlarged portion.

[0025] In this way, by providing each front side frame with a longitudinally uneven bead, it becomes easier to design the front side frame to have a strength against a load collision that is suitable for absorbing collision energy. Also, by a simple process of partially increasing the vertical dimension of the longitudinally uneven bead shape, it is possible to form an outer bead width expansion portion and an inner bead width expansion portion on the side frame. Furthermore, by a simple process of making the vertical dimension of each outer bead width expansion portion smaller than that of each inner bead width expansion portion, it is possible to make the strength of each outer bead width expansion portion higher than that of each inner bead width expansion portion.

[0026] In one embodiment, a vertical concave-convex bead extending in a vertical direction as the outer weak portion is formed on a vehicle width direction outer surface of each of the front side frames, A vertical concave-convex bead extending in the vertical direction is formed on an inner surface in the vehicle width direction of each of the front side frames as the inner weak portion, The vertical uneven bead on the vehicle width direction outer surface of each of the front side frames has a smaller vertical dimension than the vertical uneven bead on the vehicle width direction inner surface.

[0027] In this way, the outer weak portion and the inner weak portion can be formed by a simple process of forming beads extending up and down on the side frames. Also, by a simple process of making the vertically uneven bead on the outer surface of each front side frame smaller in vertical dimension than the vertically uneven bead on the inner surface, the strength of the vertically uneven bead on the outer surface can be made greater than the strength of the vertically uneven bead on the inner surface.

[0028] In one embodiment, Each of the crash cans is An upper surface portion facing upward of the vehicle; A lower surface portion facing downward toward the vehicle, A horizontal rib extending in the front-rear direction of the vehicle is formed inside each of the crash cans, Each of the crash cans is formed with a vertical rib extending in the vehicle front-rear direction and connecting the horizontal rib to the upper surface portion or the lower surface portion, A notch that opens to the upper surface or the lower surface of each of the crash cans is formed so that the upper surface or the lower surface of each of the crash cans is partially separated from the vertical rib, The notch opening in the upper surface portion or the lower surface portion is formed forward of the weakened portion on the vehicle.

[0029] In this way, each crash can is formed with a bottom notch and a top notch where stress is likely to concentrate, and a weak portion. When a vehicle undergoes an offset collision, a collision load is input to the crash can from one side of the inclined portion of the bumper beam. Since the top notch and the bottom notch are formed further forward of the vehicle than the weak portion, the collision load is first transmitted to the top notch and the bottom notch, causing stress to concentrate. As a result, the top notch and the bottom notch are first crushed and deformed. The collision load transmitted to the top notch and the bottom notch is then transmitted to the weak portion where stress is likely to concentrate. As a result, the weak portion is crushed and deformed.

[0030] In this way, by forming the upper and lower notches in the crash can, the collision load due to an offset collision is transmitted to the fragile portion via the crushing deformation of the upper and lower notches, which promotes the crushing deformation of the fragile portion and promotes the absorption of the energy of the collision load by the crash can. Effect of the Invention

[0031] According to the present invention, it is possible to absorb both the energy of a collision load due to a full-overlap collision and the energy of a collision load due to an offset collision. [Brief description of the drawings]

[0032] [Figure 1] FIG. 1 is a top view showing a front body structure of a vehicle. [Diagram 2] FIG. 2 is a bottom view showing the front body structure of the vehicle. [Diagram 3] FIG. 3 is a perspective view showing a front body structure of a vehicle. [Figure 4] FIG. 4 is a top view of the crash can. [Diagram 5] 5 is a cross-sectional view of the crash can taken along line VV in FIG. [Figure 6] FIG. 6 is a cross-sectional view of the crash can taken along line VI-VI in FIG. [Figure 7] FIG. 7 is a cross-sectional view of the crash can taken along line VII-VII in FIG. [Figure 8] 8 is a cross-sectional view of the crash can and the front side frame taken along line VIII-VIII in FIG. [Figure 9] FIG. 9 is a cross-sectional view taken along line IX-IX in FIGS. [Figure 10] FIG. 10 is a schematic diagram of FIG. [Figure 11] FIG. 11 is a side view of the front side frame. [Figure 12] FIG. 12 is a side view of the front side frame. [Figure 13] FIG. 13 is a diagram showing a crash can that has been crushed by an offset collision. [Figure 14] FIG. 10 is a SS diagram of the example and the comparative example. [Figure 15] FIG. 15 is a view corresponding to FIG. 9 according to the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0033] Hereinafter, the preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The following preferred embodiments are merely illustrative in nature and are not intended to limit the present invention, its applications, or its uses.

[0034] (Embodiment 1) 1 to 3 show a front body structure of a vehicle according to an embodiment of the present invention. The front of the vehicle includes a front side frame 1, a crash can 5, and a bumper beam 7. The front side frame 1 and the crash can 5 are provided on both sides in the vehicle width direction. Each of the crash cans 5 is attached to a front end of each of the front side frames 1. The front end of each of the crash cans 5 is connected to the bumper beam 7.

[0035] Front side frames 1 extending in the front-rear direction are provided on both sides in the vehicle width direction at the front of the vehicle. Each front side frame 1 is provided at an end on each side in the vehicle width direction of an engine room 4 in which an engine (not shown) and a transmission (not shown) for driving the vehicle are provided. Apron members 3 extending approximately in the front-rear direction of the vehicle are provided above each front side frame 1 (the front side of the paper in FIG. 1 ) and on the outer side in the vehicle width direction. Front ends of the apron members 3 are connected to each other by a shroud upper member 31.

[0036] The rear end of each of the front side frames 1 extends toward the rear of the vehicle and is formed to incline downward. A dash panel 41 that separates the engine room 4 from the passenger compartment is provided at approximately the same position in the front-to-rear direction as the rear end of each of the front side frames 1.

[0037] A suspension housing 2 is connected to the middle of each front side frame 1 in the vehicle front-rear direction. This suspension housing 2 forms a wheel house in which the front wheels (not shown) of the vehicle are arranged on the outer side of each front side frame 1 in the vehicle width direction. The suspension housings 2 provided on both sides in the vehicle width direction have their lower ends connected to the respective front side frames 1 and their upper ends connected to apron members 3. A portion of each front side frame 1 forward of the suspension housing 2 extends in the front-rear direction of the vehicle parallel to the center line of the vehicle body. A frame-side set plate is fixed to the tip of each front side frame 1. A crash-can-side set plate 50 provided at the rear end of the crash can 5 is fastened to the frame-side set plate 12. As a result, the crash can 5 is provided at the front end of the front side frame 1. This crash can 5 extends toward the front of the vehicle and is inclined outward in the vehicle width direction. Each of the crash cans 5 extends toward the front of the vehicle and is inclined outward in the vehicle width direction.

[0038] The vertical dimension at the rear end of each crash can 5 is approximately the same as the vertical dimension at the front end of each front side frame 1. Also, the vehicle width direction dimension at the rear end of each crash can 5 is approximately the same as the vehicle width direction dimension at the front end of each front side frame 1. Therefore, the outline of the rear end of each crash can 5 and the outline of the front end of the front side frame 1 have approximately the same shape, sandwiched between the crash can side set plate 50 and the frame side set plate 12.

[0039] A bumper beam 7 extending in the vehicle width direction is provided in front of these crash cans 5. Both ends of the bumper beam 7 in the vehicle width direction are provided with inclined portions 71 that extend outward in the vehicle width direction and incline toward the rear of the vehicle. The front ends of the above-mentioned crash cans 5 are connected to the inclined portions 71 provided at both ends in the vehicle width direction. The inclination angle of each of the crash cans 5 with respect to the vehicle front-rear direction is smaller than the inclination angle of the bumper beam 7 with respect to the vehicle front-rear direction in a direction perpendicular to the inclined portions 71.

[0040] <Crash Can Configuration> The crash cans 5 provided on both sides in the vehicle width direction have a symmetrical structure. Therefore, the structure of the crash can 5 on the right side in the vehicle width direction (the right side in Fig. 1) will be described in detail. As shown in Figs. 5 to 7, the crash can 5 has a rectangular cross section that is long in the vertical direction. The crash can 5 has an inner side surface portion 51 as a side surface portion facing the inside in the vehicle width direction, an outer side surface portion 52 facing the outside in the vehicle width direction, an upper surface portion 53 facing upward in the vehicle direction, and a lower surface portion 54 facing downward in the vehicle direction. The crash can is an extrusion-formed member formed by extruding a material such as an aluminum alloy or a magnesium alloy.

[0041] As shown in Fig. 5, two horizontal ribs 55 are formed inside the crash can 5 at an interval in the up-down direction (up-down direction in Fig. 5) extending horizontally (left-right direction in Fig. 5) from the inner side surface portion 51 to the outer side surface portion 52. As shown in Fig. 8, the horizontal ribs 55 are formed so as to extend in the vehicle front-rear direction (left-right direction in Fig. 8) from the front end to the rear end of the crash can 5. These horizontal ribs 55 are formed approximately parallel to the upper surface portion 53 and the lower surface portion 54 of the crash can 5.

[0042] As shown in FIG. 5, a vertical rib 56 is provided at the approximate center in the vehicle width direction (left-right direction in FIG. 5) of the horizontal rib 55 located at the upper side, and extends in the vertical direction to connect the horizontal rib 55 and the upper surface portion 53 of the crash can 5. Also, a vertical rib 56 is provided at the approximate center in the vehicle width direction of the horizontal rib 55 located at the lower side in FIG. 5, and extends in the vertical direction to connect the horizontal rib 55 and the lower surface portion 54 of the crash can 5. As shown in FIG. 8, these vertical ribs 56 are formed so as to extend in the vehicle front-rear direction from the front end portion to the rear end portion of the crash can 5. These vertical ribs 56 are formed approximately parallel to the inner side surface portion 51 and the outer side surface portion 52 of the crash can 5.

[0043] As shown in Fig. 4, the crash can 5 has three ridge notches 60 formed at intervals in the vehicle front-rear direction (left-right direction in Fig. 4) by cutting out the ridge line formed by the inner side surface portion 51 and the upper surface portion 53. A cross-sectional view passing through these ridge notches 60 is shown in Fig. 6.

[0044] 6, the crash can 5 has a ridge notch 60 formed by cutting out a ridge between the inner side surface portion 51 and the upper surface portion 53. The crash can 5 also has a ridge notch 60 formed by cutting out a ridge between the inner side surface portion 51 and the lower surface portion 54. The location of the crash can 5 where the ridge notch 60 is formed is a weak portion that has low strength against a collision load from the front of the vehicle.

[0045] 6, a side notch 61 that opens into the inner side surface portion 51 is formed in the inner side surface portion 51 of the crash can 5 so that the inner side surface portion 51 and the horizontal rib 55 are partially separated. The location of the crash can 5 where the side notch 61 is formed is a weak portion that has low strength against a collision load input to the bumper beam 7.

[0046] In this manner, the ridge notch 60 and the side notch 61 as weak portions are provided on the inner side in the vehicle width direction of the crash can 5. Therefore, the strength of the crash can 5 against a collision load from the front of the vehicle is lower on the inner side in the vehicle width direction than on the outer side in the vehicle width direction.

[0047] 4 and 6, in this embodiment, the ridge notch 60 and the side notch 61 are formed so as to be at approximately the same distance from the rear end of the crash can 5. However, the ridge notch 60 and the side notch 61 may be formed so as to be at different distances from the rear end of the crash can 5.

[0048] As shown in Fig. 4, an upper surface notch 62 that opens into the upper surface portion 53 is formed on the vehicle front side of the above-mentioned ridge line notch 60 of the upper surface portion 53 of the crash can 5. A cross-sectional view passing through this upper surface notch 62 is shown in Fig. 7.

[0049] As shown in Fig. 7, the upper surface portion 53 of the crash can 5 is provided with an upper surface notch 62 so that the upper (upper side in Fig. 7) vertical rib 56 and the upper surface portion 53 are partially separated. Also, the lower surface portion 54 of the crash can 5 is provided with a lower surface notch 63 so that the lower (lower side in Fig. 7) vertical rib 56 and the lower surface portion 54 are partially separated.

[0050] <Front side frame configuration> The front side frames 1 provided on both sides in the vehicle width direction have a symmetrical structure. Therefore, the structure of the front side frame 1 on the right side in the vehicle width direction (the right side in FIG. 1) will be described in detail. As shown in FIG. 9 and FIG. 10, the front side frame 1 is formed by joining an outer panel 13 arranged on the outer side in the vehicle width direction and an inner panel 14 arranged on the inner side in the vehicle width direction. The outer panel 13 and the inner panel 14 are formed by pressing a steel plate or the like. An outer flange 131 for joining is formed on the upper and lower parts of the outer panel 13. In addition, an inner flange 141 for joining is formed on the upper and lower parts of the inner panel 14. These outer flanges 131 and the inner flanges 141 are joined by spot welding or the like. The joining position of the outer panel 13 and the inner panel 14 is inside the center of the front side frame 1 in the vehicle width direction.

[0051] Fig. 11 is a view of the front side frame 1 as seen from the outside in the vehicle width direction. As shown in Fig. 11, an outer front-rear uneven bead 132 is provided on the outer panel 13 of the front side frame 1 as a front-rear uneven bead extending in the front-rear direction of the vehicle (left-right direction in Fig. 11). An outer bead width expanded portion 133 in which the bead width is partially expanded is formed on the vehicle front side (right side in Fig. 11) of the outer front-rear uneven bead 132. The location of the front side frame 1 where the outer bead width expanded portion 133 is provided is an outer weak portion that has low strength against a collision load from the front of the vehicle.

[0052] Fig. 12 is a view of the front side frame 1 as seen from the inside in the vehicle width direction. As shown in Fig. 12, an inner front-rear concave-convex bead 142 is provided on the inner panel 14 of the front side frame 1 as a front-rear concave-convex bead extending in the front-rear direction of the vehicle (left-right direction in Fig. 12). An inner bead width expanded portion 143 in which the bead width is partially expanded is formed on the vehicle front side (left side in Fig. 12) of the inner front-rear concave-convex bead 142. The location of the front side frame 1 where the inner bead width expanded portion 143 is provided is an inner weak portion that has low strength against a collision load from the front of the vehicle.

[0053] Fig. 9 shows a cross section of the front side frame 1 passing through the above-mentioned outer bead width expansion portion 133 and inner bead width expansion portion 143. Fig. 10 shows the contour shape of the cross section shown in Fig. 9. As shown in Fig. 10, the vertical dimension of the outer bead width expansion portion 133 is smaller than the vertical dimension of the inner bead width expansion portion 143. For this reason, the outer bead width expansion portion 133 has higher strength against a collision load from the front of the vehicle than the inner bead width expansion portion 143.

[0054] <Effects during offset collisions> First, the action and effect during an offset collision will be described. When the vehicle according to the present invention undergoes an offset collision, the collision load is input to the bumper beam 7 via the front bumper or the like. An inclined portion 71 is provided at the end of the bumper beam 7 on the outer side in the vehicle width direction. The collision load of the offset collision is input to the crash can 5 via this inclined portion 71. Therefore, the crash can 5 receives a collision load having a component in a direction perpendicular to the inclined portion 71 of the bumper beam 7.

[0055] The crash can 5 receives a compressive force between the inclined portion 71 of the bumper beam 7 and the front side frame 1 due to the collision load of the offset collision. The crash can 5 extends toward the front of the vehicle and is inclined outward in the vehicle width direction. In other words, the axial direction of the crash can 5 is inclined in a direction perpendicular to the inclined portion 71 of the bumper beam 7 with respect to the vehicle front-rear direction. Therefore, when a collision load perpendicular to the inclined portion 71 is input to the crash can 5, the load component in the axial direction of the crash can becomes large in the collision load input to the crash can 5. This prevents the crash can 5 from being bent inward from its base due to the collision load of the offset collision, and the crash can 5 is easily crushed and deformed in the axial direction (longitudinal direction).

[0056] FIG. 13 shows the crash can 5 starting to be crushed and deformed by the collision load of the offset collision. The crash can 5 is provided with an upper surface notch 62 and a lower surface notch 63 where stress is likely to concentrate, and a ridge notch 60 and a side surface notch 61 on the inner side in the vehicle width direction. The upper surface notch and the lower surface notch 63 are formed on the vehicle front side and on the outer side in the vehicle width direction than the ridge notch 60 and the side surface notch 61. Therefore, the collision load due to the offset collision is first transmitted to the upper surface notch 62 and the lower surface notch 63, and the stress is concentrated on the upper surface notch 62 and the lower surface notch 63. Then, the upper surface notch 62 and the lower surface notch 63 are crushed and deformed. After that, the collision load transmitted to the upper surface notch 62 and the lower surface notch 63 is transmitted to the ridge notch 60 and the side surface notch 61 on the inner side in the vehicle width direction where stress is likely to concentrate. As a result, stress is concentrated in the edge notch 60 and the side notch 61, causing the edge notch 60 and the side notch 61 to be crushed and deformed.

[0057] In this way, by providing the upper surface notch 62 and the lower surface notch 63 in the crash can 5, when a collision load of an offset collision is input to the bumper beam 7, stress is concentrated in the ridge notch 60 and the side surface notch 61. This prevents stress from concentrating on the rear end (base portion) of the crash can 5. This prevents the crash can 5 from being displaced in an unintended direction, such as buckling, and makes the crash can 5 more likely to be crushed and deformed.

[0058] In addition, the contour shape of the rear end of the crash can 5 is substantially the same as the contour shape of the front end of the front side frame 1. Therefore, when a collision load of an offset collision is input to the crash can 5 through the inclined portion 71 of the bumper beam 7, the rear end of the crash can 5 can be firmly supported by the front end of the front side frame 1. Therefore, the crash can 5 is prevented from being displaced in an unintended direction, such as buckling, due to the collision load, and the crash can 5 is more likely to be crushed and deformed.

[0059] Looking at the load input in the axial direction of the crash can 5, the load input to the outer surface portion 52 of the crash can 5 is greater than the load input to the inner surface portion 51. Therefore, while the outer surface portion 52 is easily plastically distorted in the axial direction and acts to absorb the collision energy, the inner surface portion 51 is less likely to suffer from the above-mentioned plastic distortion. Therefore, the inner surface portion 51 is provided with a ridge notch 60 and a side notch 61 as weakened portions, so that the inner surface portion 51 also suffers from plastic distortion in the same way as the outer surface portion 52, thereby improving the absorption of collision energy.

[0060] In addition, a force bending the crash cans 5 inward in the vehicle width direction is applied to the crash cans 5 due to the collision load of the offset collision. Then, a force bending the crash cans 5 inward in the vehicle width direction is applied to the front side frames 1 via the crash cans 5.

[0061] When the front side frame is bent and deformed by this bending force inward in the vehicle width direction, the outer side of the front side frame in the vehicle width direction is the tension side, and the inner side in the vehicle width direction is the compression side. For this reason, by making the bead width of the inner bead width expansion portion 143 wider than the bead width of the outer bead width expansion portion 133 of the front side frame 1, the strength of the outer side in the vehicle width direction of the front side frame 1 is made stronger than the strength of the inner side in the vehicle width direction, thereby suppressing bending deformation of the front side frame 1 due to this moment.

[0062] In this way, the front side frame 1 does not bend or deform due to the input of the collision load of an offset collision, and the rear end of the crash can 5 is firmly supported by the front end of the front side frame 1. This prevents the crash can 5 from being displaced in an unintended direction, such as buckling, due to the collision load of an offset collision, and makes the crash can 5 more likely to be crushed and deformed.

[0063] Also, if it is only necessary to make the strength of the outer side in the vehicle width direction of the front side frame 1 higher than the strength of the inner side in the vehicle width direction, it is possible to provide only the inner bead width enlarged portion 143 and not the outer bead width enlarged portion 133. However, by providing the outer bead width enlarged portion 133 on the front side frame 1, the strength of the front side frame 1 on the vehicle rear side becomes higher than the strength of the front side of the vehicle. For this reason, when a collision load due to a vehicle collision is input to the front side frame 1, the front side frame 1 is crushed and deformed successively from the front of the vehicle toward the rear of the vehicle.

[0064] As described above, the crash can 5 is crushed and deformed between the bumper beam 7 and the front side frame 1 without buckling or the like, so that energy absorption performance is exhibited against the collision load of an offset collision.

[0065] <Effectiveness during full-wrap collision> Next, the operation and effect during a full-overlap collision will be described. When the vehicle according to the present invention is involved in a full-overlap collision, a collision load is input from the front of the vehicle. This collision load is input to the bumper beam 7 via a front bumper or the like (not shown). The collision load input to the bumper beam 7 causes a compressive force to act on each of the crash cans 5 on both sides in the vehicle width direction.

[0066] Each crash can 5 is attached to each front side frame 1. Therefore, each crash can 5 receives a compressive force between the bumper beam 7 and the front side frame 1.

[0067] As described above, the crash can 5 is inclined in consideration of the absorption of collision energy in the case of an offset collision. Therefore, due to the inclination, the crash can 5 is likely to fall outward from its base in a full-wrap collision. Therefore, the inner surface portion 51 of the crash can 5 is formed with a ridge notch 60 and a side notch 61 as weak parts. Therefore, when the above-mentioned compressive force is applied, stress is concentrated in the ridge notch 60 and the side notch 61 of the crash can 5. As a result, the crash can 5 is more likely to undergo plastic deformation on the inner surface portion 51 side than on the outer surface portion 52 side. In this way, the crash can is prevented from falling outward in a full-wrap collision, and the crash can 5 is crushed and deformed, thereby improving the absorption of collision energy.

[0068] In addition, the contour shape of the rear end of each crash can 5 is substantially the same as the contour shape of the front end of each front side frame 1. Therefore, when a collision load is input to the crash can 5 via the bumper beam 7, the rear end of the crash can 5 can be firmly supported by the front end of the front side frame 1. Therefore, the crash can 5 is prevented from being displaced in an unintended direction, such as buckling, due to the collision load, and the crash can 5 is more likely to be crushed and deformed.

[0069] In this way, the crash can 5 is crushed and deformed between the bumper beam 7 and the front side frame 1 without buckling or the like, so that energy absorption performance is exhibited against the collision load of a full-overlap collision.

[0070] Further, the front side frame 1 is provided with an outer bead width expansion portion 133 and an inner bead width expansion portion 143. This makes the strength of the rear side of the vehicle stronger than the strength of the front side of the vehicle in the front side frame 1. Therefore, when a collision load due to a vehicle collision is input to the front side frame 1, the front side frame 1 is crushed and deformed successively from the front of the vehicle toward the rear of the vehicle.

[0071] <Embodiments and Comparative Examples> FIG. 14 shows FS diagrams of a crash can 5 as an example according to an embodiment of the present invention, a straight crash can as comparative example 1, and an inclined crash can as comparative example 2. This FS diagram shows the buckling load of the crash can due to an offset collision and the amount of crushing of the crash can crushed by the collision load. The vertical axis of this FS diagram is the buckling load (kN) of the crash can due to an offset collision. The horizontal axis of this FS diagram is the amount of crushing of the crash can (mm). This graph shows the characteristics of each crash can. The area of ​​the region surrounded by each graph and the vertical and horizontal axes is the total amount of energy absorbed by each crash can during an offset collision.

[0072] Comparative Example 1 is a conventional straight crash can that extends from the front end of the front side frame toward the front of the vehicle. The straight crash can of Comparative Example 1 is not provided with a weak portion.

[0073] Comparative Example 2 is an inclined crash can that extends from the front end of the front side frame toward the front of the vehicle and is inclined outward in the vehicle width direction. The inclined crash can of Comparative Example 2 is not provided with a weak portion, like Comparative Example 1.

[0074] The embodiment is an inclined crash can that extends from the front end of the front side frame toward the front of the vehicle and is inclined outward in the vehicle width direction. Also, an inner weakened portion is formed to reduce strength against a collision load input to the bumper beam.

[0075] As shown in Fig. 14, in the case of Comparative Example 1, the crash cans quickly tip inward (buckle) from their bases due to an offset collision, resulting in a low load rise and small amount of crushing. When the crash cans are tilted as in Comparative Example 2, the input direction of the collision load approaches the axial direction of the crash cans, resulting in a higher load level and improved load duration. However, when looking at the axial load input to the crash cans, the input to the outer ridges in the vehicle width direction is greater than that to the inner ridges, so the crash cans are more likely to tip inward. As a result, the load duration does not extend very much.

[0076] In contrast, in the case of the embodiment, the inner weak portion reduces the difference in load input between the inner and outer sides of the crash can in the vehicle width direction, and the inner ridgeline and the outer ridgeline show similar deformation behavior. As a result, the load duration (crushing amount) is extended, and the overall collision energy absorption amount can be significantly improved.

[0077] (Embodiment 2) Hereinafter, the second embodiment will be described in detail with reference to the drawings. In the following description, the same reference numerals are used to designate the same parts as those in the first embodiment, and detailed description thereof will be omitted.

[0078] In the second embodiment, the shapes of the outer weak portion and the inner weak portion formed on the front side frames 1 provided on both sides in the vehicle width direction are different. Specifically, in the second embodiment, as shown in Fig. 15, an outer vertically uneven bead 134 extending vertically is formed as the outer weak portion on the outer surface in the vehicle width direction of the front side frame 1. Also, an inner vertically uneven bead 144 extending vertically is formed as the inner weak portion on the inner surface in the vehicle width direction of the front side frame 1. The vertical dimension of this outer vertically uneven bead 134 is smaller than the vertical dimension of the inner vertically uneven bead 144. As a result, the strength of the outer vertically uneven bead 134 is higher than the strength of the inner vertically uneven bead 144.

[0079] In this way, the outer weak portion and the inner weak portion can be formed by a simple process of providing uneven beads extending vertically on the front side frame 1. Also, by a simple process of making the vertical dimension of the outer vertically uneven bead 134 smaller than the vertical dimension of the inner vertically uneven bead 144, the strength of the outer vertically uneven bead 134 can be made greater than the strength of the inner vertically uneven bead 144.

[0080] In addition, since the configuration of the second embodiment is the same as that of the first embodiment except for the outer weak portion and the inner weak portion, the description thereof will be omitted. [Explanation of symbols]

[0081] 1 Front side frame 2 Suspension housing 5. Crash Can 7 Bumper Beam 60 Ridge Notch 61 Side notch 62 Top notch 63 Bottom notch 71 Slope 132 Outer front and rear uneven beads 133 Outer bead width expansion part 134 Outer vertical uneven bead 142 Inside front and rear uneven beads 143 Inner bead width expansion part 144 Inner vertical uneven bead

Claims

1. A front body structure of a vehicle including front side frames extending in a front-rear direction of the vehicle provided on each of the left and right sides of the vehicle, and a bumper beam provided forward of each of the front side frames and having inclined portions extending outward in the vehicle width direction at both ends in the vehicle width direction and inclined toward the rear of the vehicle, A crash can is provided at a front end of each of the front side frames, the crash can extending toward the front of the vehicle and inclining outward in the vehicle width direction, A front end portion of each of the crash cans is connected to each of the inclined portions of the bumper beam, A weak portion having a reduced strength against a collision load from the front of the vehicle is provided on an inner side of each of the crash cans in the vehicle width direction, A suspension housing is connected to a middle portion of each of the front side frames in the vehicle front-rear direction, an outer weakened portion having a reduced strength against a collision load from the front of the vehicle is provided on an outer side of each of the front side frames in the vehicle width direction, the outer weakened portion being located forward of the suspension housing; an inner weakened portion having a reduced strength against a collision load from the front of the vehicle is provided on an inner side in the vehicle width direction of each of the front side frames, the inner weakened portion being located forward of the suspension housing; 13. A front body structure for a vehicle, wherein the outer weak portion of each of the front side frames has a strength greater than that of the inner weak portion.

2. 2. The front body structure of a vehicle according to claim 1, a cross-sectional outline of each of the crash cans at a rear end and a cross-sectional outline of each of the front side frames at a front end, the cross-sectional outline having substantially the same shape.

3. The front body structure of a vehicle according to claim 1 or 2, Each of the crash cans is A side portion facing the inside in the vehicle width direction; An upper surface portion facing upward of the vehicle; A lower surface portion facing downward toward the vehicle, A front body structure for a vehicle, wherein the weak portion is formed by a ridge notch that cuts out at least one of the ridges formed by the side portion and the upper surface portion and the lower surface portion.

4. In the front body structure of a vehicle according to any one of claims 1 to 3, A horizontal rib extending in the front-rear direction of the vehicle is formed inside each of the crash cans, a side notch that opens toward the inside in the vehicle width direction so that the side portion of the crash can on the inside in the vehicle width direction and the horizontal rib are partially separated from each other.

5. In the front body structure of a vehicle according to any one of claims 1 to 4, A longitudinal concave-convex bead extending in the longitudinal direction of the vehicle is provided on both side surfaces of each of the front side frames in the vehicle width direction, The longitudinal concave and convex bead provided on the vehicle width direction outer side of each of the front side frames is formed with an outer bead width expansion portion as the outer weak portion obtained by partially increasing the bead width, The longitudinal concave and convex bead provided on the vehicle width direction inner side of each of the front side frames is formed with an inner bead width expansion portion as the inner weak portion by partially increasing the bead width, A front body structure for a vehicle, wherein the outer bead width expansion portion of each of the front side frames has a bead width smaller than that of the inner bead width expansion portion.

6. The front body structure of a vehicle according to any one of claims 1 to 5, A vertical concave-convex bead extending in the vertical direction is formed on the vehicle width direction outer surface of each of the front side frames as the outer weak portion, A vertical concave-convex bead extending in the vertical direction is formed on an inner surface in the vehicle width direction of each of the front side frames as the inner weak portion, A front body structure for a vehicle, characterized in that the vertical uneven bead on the vehicle width direction outer surface of each of the front side frames has a smaller vertical dimension than the vertical uneven bead on the vehicle width direction inner surface.

7. The front body structure of a vehicle according to any one of claims 1 to 6, Each of the crash cans is An upper surface portion facing upward of the vehicle; A lower surface portion facing downward toward the vehicle, A horizontal rib extending in the front-rear direction of the vehicle is formed inside each of the crash cans, Each of the crash cans has: A vertical rib is formed to connect the horizontal rib to the upper surface portion or the lower surface portion and extend in the vehicle front-rear direction, A notch is formed in the upper surface portion or the lower surface portion of each of the crash cans so that the upper surface portion or the lower surface portion of each of the crash cans is partially separated from the vertical rib, A front body structure for a vehicle, characterized in that the notch opening in the upper surface portion or the lower surface portion is formed forward of the weak portion.

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