Front side member

Abstract

To obtain a front side member which enables reduction of deterioration of energy absorption efficiency caused by a portion which is not be collapsed and can secure an intended energy absorption amount.SOLUTION: A front side member 10 extends in a vehicle fore and aft direction at each of left and right sides as seen in a vehicle width direction, has an open cross section shape in which an opening 110 is provided on at least one side in the vehicle width direction, and is integrally molded by die casting. The front side member 10 includes a plurality of ribs 20 which connect a bottom surface 112A at the opposite side of the opening 110, a lower surface 114A of an upper wall 114 in a vehicle vertical direction, and an upper surface 116A of a lower wall 116. In the rib 20, a rib minimum height H along the vehicle width direction is set so as to be a half of or higher than width direction dimensions D of the upper wall 114 and the lower wall 116.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a front side member. [Background technology]

[0002] Patent Document 1 discloses a structure that absorbs energy by breaking a skeletal member formed by integral molding such as casting during a collision. The skeletal member described in Patent Document 1 has a U-shaped cross section with the mold opening direction perpendicular to the load transmission direction. The skeletal member has multiple chambers separated by wall-like ribs perpendicular to the load transmission direction, and the ribs are hollowed out in a C-shape. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2022 / 031991 Summary of the Invention [Problem to be solved by the invention]

[0004] When the skeleton member described in Patent Document 1 is subjected to a collision load and is crushed successively from the tip, the deformation of the second chamber is dragged along with the collapse of the first chamber, and the wall buckles in the opposite direction to the first chamber. Therefore, when the wall of the first chamber is deformed convexly toward the outside, the wall of the even-numbered chamber is deformed convexly toward the inside, i.e., is deformed concavely, and fragments may remain inside the skeleton member, causing a crushed residue. When a crushed residue occurs, the vehicle deformation (stroke) cannot be sufficiently taken by the amount of the crushed residue, and the energy absorption efficiency decreases. On the other hand, if the C-shaped hollowed-out portion is eliminated to suppress the occurrence of the crushed residue, the occurrence of the crushed residue can be suppressed, but the crushed load in each chamber may become too large, and the intended energy absorption amount may not be secured.

[0005] SUMMARY OF THE PRESENT INVETION The present invention has been made in consideration of the above circumstances, and has an object to provide a front side member that can reduce the decrease in energy absorption efficiency caused by residual crushing and ensure the intended amount of energy absorption. [Means for solving the problem]

[0006] The front side member according to the present invention described in claim 1 is a front side member that extends in the vehicle front-rear direction on both the left and right sides in the vehicle width direction, has an open cross-sectional shape with an opening on at least one side in the vehicle width direction, and is integrally molded by die casting, and includes a plurality of ribs that connect a bottom surface on the side opposite the opening to a lower surface of an upper wall and an upper surface of a lower wall in the vehicle vertical direction, and the ribs have a minimum rib height along the vehicle width direction set to half or more of the width direction dimensions of the upper wall and the lower wall. The minimum rib height is set higher toward the rear of the vehicle. do.

[0007] The front side member according to the present invention described in claim 1 has an open cross-sectional shape with an opening on at least one side in the vehicle width direction and is integrally molded by die casting. The front side member also has a plurality of ribs connecting the bottom surface on the side opposite the opening to the lower surface of the upper wall in the vehicle vertical direction and the upper surface of the lower wall. In this way, by reinforcing the wall surfaces with a plurality of ribs, when a certain room among a plurality of rooms each separated by a plurality of ribs is destroyed, the deformation is completed within the certain room. Therefore, the tendency of deformation such as a concave or convex shape is not propagated to the wall surface of the room adjacent to the certain room. Therefore, the wall surfaces in the vehicle vertical direction of all rooms can be bent so as to be convex toward the outside of the front side member. This makes it possible to suppress accumulation of fragments of cracks due to a collision load applied to the front side member inside the front side member, thereby reducing a decrease in energy absorption efficiency due to residual crushing.

[0008] In the front side member according to the present invention described in claim 1, the minimum rib height along the vehicle width direction is set to be equal to or greater than half the widthwise dimensions of the upper wall and the lower wall. In this way, by adjusting the minimum rib height, i.e., the depth of the hollowed-out portion hollowed out from the opening side toward the vehicle width direction, the crushing load in the chambers separated by the rib can be controlled, and the intended amount of energy absorption can be ensured.

[0010] Claim 1 In the front side member according to the present invention described above, the minimum rib height is set to increase toward the rear of the vehicle. In other words, the depth of the recessed portion decreases toward the rear of the vehicle. This increases the crush load from the front side of the vehicle to the rear of the front side member, making it easier to crush from the front side of the vehicle onward, thereby improving the robustness of deformation during a collision.

[0011] Claim 2 The front side member according to the present invention is 1 to In the described configuration, the open cross-sectional shape is a U-shaped cross-sectional shape, and the opening is provided on the outer side in the vehicle width direction.

[0012] Claim 2 According to the front side member of the present invention described in the above, since the cross-sectional shape is U-shaped and the opening is provided on the outer side in the vehicle width direction, a wall exists on the inner side in the vehicle width direction, which makes it possible to prevent fragments from flying to, for example, a power unit arranged on the inner side in the vehicle width direction.

[0013] Claim 3 The front side member according to the present invention is 1 to In the described configuration, the open cross-sectional shape is an H-shaped cross-sectional shape, and the openings are provided on the inner and outer sides in the vehicle width direction.

[0014] Claim 3According to the front side member of the present invention described in the above, the cross-sectional shape is an H-shape, and the openings are provided on the inside and outside in the vehicle width direction, so that a wall exists in the center of the front side member in the vehicle width direction, thereby making it possible to control the crushing load on each of both sides in the vehicle width direction of the front side member.

[0015] Claim 4 The front side member according to the present invention is 3 In the configuration described in any one of the above, the rib has a hollowed-out portion whose tip is hollowed out in an arc shape from the opening side toward the vehicle width direction.

[0016] Claim 4 In the front side member of the present invention described above, the recessed portion provided on the rib has a tip that is recessed in an arc shape, making the central portion of the front side member in the vertical direction of the vehicle more susceptible to crushing, and making it easier for a convex deformation that convexly forms outward on the wall surface in the vertical direction of the vehicle to occur. Effect of the Invention

[0017] As described above, the front side member according to the present invention has the excellent effect of reducing the decrease in energy absorption efficiency caused by residual crushing and ensuring the intended amount of energy absorption. [Brief description of the drawings]

[0018] [Figure 1] 1 is a plan view showing an example of a main part of a vehicle front portion including a front side member according to a first embodiment of the present invention. FIG. [Diagram 2] 2 is a perspective view of a front side member as viewed diagonally from the front side of the vehicle. FIG. [Diagram 3] 3 is a cross-sectional view taken along line AA in FIG. 2. [Figure 4] FIG. 4 is a cross-sectional view showing a modified example corresponding to FIG. [Diagram 5] FIG. 2 is a perspective view of a front side member of Comparative Example 1 as viewed obliquely from the front side of the vehicle. [Figure 6] 6 is a side view that illustrates an analysis result when a collision load is applied to the front side member of Comparative Example 1 in FIG. 5. [Figure 7] FIG. 7 is a diagram showing a schematic diagram of an analysis result when a collision load is further applied to the front side member of Comparative Example 1 from the state shown in FIG. 6. [Figure 8] FIG. 11 is a vertical sectional view of a front side member of Comparative Example 2. [Figure 9] FIG. 11 is a side view that illustrates an analysis result when a collision load is applied to the front side member of Comparative Example 2. [Figure 10] 10 is a diagram showing a schematic diagram of an analysis result when a collision load is further applied to the front side member of Comparative Example 2 from the state shown in FIG. 9. [Figure 11] FIG. 11 is a side view showing a schematic state in which a crushed residue occurs. [Figure 12] FIG. 11 is a perspective view of a front side member according to a second embodiment of the present invention, as viewed obliquely from the front side of the vehicle. [Figure 13] 13 is a cross-sectional view taken along line BB in FIG. 12. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] (Embodiment 1) Hereinafter, a vehicle front structure 100 including a front side member 10 according to a first embodiment of the present invention will be described with reference to the drawings. Since the vehicle front structure 100 is a symmetrical structure, only the left side is shown in each drawing, and the right side is omitted. In addition, an arrow FR shown as appropriate in each drawing indicates the front side in the vehicle longitudinal direction, and an arrow UP indicates the upper side in the vehicle vertical direction. In addition, an arrow LH indicates the left side in the vehicle width direction, and in this embodiment, indicates the outer side in the vehicle width direction. In this embodiment, for convenience, the left side of the vehicle is the outer side in the vehicle width direction, and the right side of the vehicle is the inner side in the vehicle width direction (the center side in the vehicle width direction). Hereinafter, when the directions of the front-rear, the up-down, and the left-right are simply used for the description, they indicate the front-rear in the vehicle longitudinal direction, the up-down in the vehicle vertical direction, and the left-right in the vehicle lateral direction (the vehicle width direction), unless otherwise specified. In addition, the present invention can be applied even in a configuration in which the right side of the vehicle is the outer side in the vehicle width direction and the left side of the vehicle is the inner side in the vehicle width direction (the center side in the vehicle width direction), as in the case of a symmetrical configuration with respect to the configuration of this embodiment.

[0020] (Vehicle front structure configuration) First, the configuration of a vehicle front structure 100 will be described. Fig. 1 is a plan view showing an example of a main part of a vehicle front including a front side member 10 according to a first embodiment of the present invention. As shown in Fig. 1, in this embodiment, the vehicle front structure 100 is incorporated in, as an example, an electric vehicle or a fuel cell vehicle that runs on power generated by a power unit P. A power unit chamber 11 in which the power unit P is installed is provided at the front of the vehicle.

[0021] The vehicle front structure 100 includes a pair of left and right front side members 10, which are lateral framework members of the vehicle and are arranged on both sides of the front part of the vehicle in the vehicle width direction. The front side members 10 extend in the vehicle longitudinal direction, and the ends of the front side members 10 on the vehicle rear side are connected to a cross member (not shown). In addition, the vehicle front end of the front side member 10 is connected to a front bumper reinforcement (not shown; hereinafter, referred to as "bumper RF") arranged along the vehicle width direction. In this embodiment, as an example, a crash box 14 serving as an energy absorbing member is interposed between the front side member 10 and the bumper RF.

[0022] The crash boxes 14 are configured to deform when the vehicle undergoes a frontal collision, absorbing part of the energy of the collision before the front side members 10 deform. When an impact load is transmitted from the bumper RF to the crash boxes 14, the crash boxes 14 are compressed in the front-rear direction.

[0023] A pair of left and right apron upper members 15 extending in the vehicle up-down direction are disposed on the vehicle width direction outer side of the vehicle rear side of the front side member 10. In addition, a pair of left and right fender aprons 16 are disposed on the vehicle width direction outer side of the front side member 10 and on the vehicle front side of the apron upper member 15. The apron upper member 15 has a generally rectangular cross-sectional shape that is open on the vehicle width direction outer side.

[0024] A dash panel 17 is disposed on the vehicle rear side of the front side member 10 and between the pair of left and right apron upper members 15. The dash panel 17 is a member that separates the power unit compartment 11 from the vehicle interior (not shown) and extends in the vehicle width direction and the vehicle up-down direction with its plate thickness direction being the vehicle front-rear direction. An end of the dash panel 17 in the vehicle width direction is connected to the fender apron 16.

[0025] Meanwhile, a suspension tower 18 is provided above the vehicle on the outer side in the vehicle width direction of the rear side of the front side member 10. The vehicle lower side of the suspension tower 18 is joined to a fender apron 16, which is formed to bulge inward in the vehicle width direction and also forms a wheel house in which a front wheel (not shown) is housed so as to be steerable.

[0026] The suspension tower 18 is provided so as to protrude upwards of the vehicle in a generally cylindrical shape from the wheel house, i.e., the bulging portion, of the fender apron 16. The suspension tower 18 houses inside thereof shock absorbers and springs that constitute a suspension (not shown) that supports the front wheels housed in the wheel house of the fender apron 16.

[0027] Furthermore, the vehicle front structure 100 including at least the pair of left and right front side members 10 and the pair of left and right suspension towers 18 is integrally molded by aluminum die casting. In this embodiment, the pair of left and right front side members 10, the pair of left and right suspension towers 18, and peripheral parts of the pair of left and right suspension towers 18, i.e., the apron upper member 15, the fender apron 16, and the dash panel 17, are integrally molded by aluminum die casting.

[0028] Next, the structure of the front side member 10 will be described below. In this embodiment, as shown in Fig. 1, the surface of the front side member 10 on the right side of the vehicle is referred to as an inner surface 10A, and the surface on the left side of the vehicle is referred to as an outer surface 10B. Fig. 2 is a perspective view showing a schematic configuration of the front end portion of the front side member 10.

[0029] 2, the front side member 10 has an open cross-sectional shape that is open on the outer side in the vehicle width direction, specifically, a U-shaped cross-sectional shape. The front side member 10 has an opening 110 on the outer side in the vehicle width direction, and has a bottom wall 112 on the side opposite the opening 110, i.e., on the inner side in the vehicle width direction. The front side member 10 also has an upper wall 114 on the upper side of the vehicle and a lower wall 116 on the lower side of the vehicle.

[0030] The front side member 10 includes a plurality of ribs 20 in the vehicle front-rear direction that connect a bottom surface 112A on the outer side (left side) in the vehicle width direction of the bottom wall 112, a lower surface 114A on the lower side of the upper wall 114, and an upper surface 116A on the upper side of the lower wall 116. As an example, the front side member 10 of the present embodiment has eight ribs 20, namely a first rib 20A to an eighth rib 20H, from the front to the rear of the vehicle.

[0031] 2, in the front side member 10, one chamber 24 is formed by adjacent ribs 20, a bottom surface 112A, a lower surface 114A, and an upper surface 116A. The front side member 10 of the present embodiment has, as an example, seven chambers 24, a first chamber 24A to a seventh chamber 24G.

[0032] Fig. 3 is a cross-sectional view taken along line AA in Fig. 2. As shown in Fig. 2 and Fig. 3, among the multiple ribs 20, as an example, the first rib 20A to the sixth rib 20F have a hollowed-out portion 22 in which the tip is hollowed out in an arc shape from the opening 110 side toward the inside in the vehicle width direction. In this embodiment, as shown in Fig. 3, the height of the position where the height in the vehicle width direction of the rib 20 is the lowest is defined as the rib minimum height H, and the dimension in the vehicle width direction of the upper wall 114 and the lower wall 116 is defined as the width dimension D. The rib minimum height H is set to be half or more of the width dimension D, i.e., H≧D / 2.

[0033] 2, the first rib 20A to the sixth rib 20F have a rib minimum height H that increases from the front to the rear of the vehicle, i.e., from the first rib 20A to the sixth rib 20F. In other words, the width of the hollowed out portion 22 of the rib 20 decreases from the first rib 20A to the sixth rib 20F.

[0034] In this embodiment, as shown in Fig. 3, the rib 20 has a gouged portion 22 whose tip is gouged in an arc shape, but the present invention is not limited to this. For example, as a modified example shown in Fig. 4, the gouged portion 22-2 may have a tip that is gouged in a straight line.

[0035] (Effects of the first embodiment) Next, the effects of the first embodiment will be described.

[0036] The front side member 10 according to the first embodiment has a U-shaped cross section with an opening 110 provided on the outer side in the vehicle width direction, and is integrally molded by aluminum die casting. The front side member 10 also has a plurality of ribs 20 that connect a bottom surface 112A on the side opposite the opening 110 to a lower surface 114A of an upper wall 114 and an upper surface 116A of a lower wall 116 in the vehicle vertical direction. By reinforcing the wall surfaces with the plurality of ribs 20 in this manner, when a certain room 24 out of a plurality of rooms 24 separated by the plurality of ribs 20 is destroyed, the deformation due to the destruction is completed within that certain room 24.

[0037] Therefore, the tendency for deformation such as a concave or convex shape is not propagated to the wall surfaces of the rooms 24 adjacent to the certain room 24. Therefore, the wall surfaces in the vehicle vertical direction of all the rooms 24 can be bent so as to be convex toward the outside of the front side member 10. This makes it possible to suppress accumulation of fragments of cracks caused by a collision load applied to the front side member 10 inside the front side member 10, thereby reducing a decrease in energy absorption efficiency due to residual crushing.

[0038] Fig. 5 is a perspective view of the front side member 30 of Comparative Example 1 as viewed from the diagonally forward side of the vehicle. As shown in Fig. 5, the front side member 30 of Comparative Example 1 has a plurality of vertical ribs 32 extending in the vehicle vertical direction in the vehicle front-rear direction. The front side member 30 of Comparative Example 1 also has a horizontal rib 34 extending in the vehicle front-rear direction in the center in the vehicle vertical direction. The front side member 30 of Comparative Example 1 has, as an example, one horizontal rib 34 and eight vertical ribs 32. The front side member 30 of Comparative Example 1 also has a total of 14 chambers 36, seven on each of the first and second stages in the vehicle vertical direction, which are partitioned by the one horizontal rib 34 and the eight vertical ribs 32.

[0039] In the front side member 10 of the above-described first embodiment, the rib 20 is provided with the gouged portion 22, whereas the vertical rib 32 of the front side member 30 of Comparative Example 1 is not provided with a gouged portion. Thus, an analysis was performed by applying a predetermined impact load from the front side of the vehicle to the front side member 30 of Comparative Example 1, which is provided with the vertical rib 32 without a gouged portion.

[0040] FIG. 6 is a side view showing a schematic analysis result when a collision load is applied to the front side member 30 of the comparative example 1 of FIG. 5. As shown in FIG. 6, the first chamber 36A from the vehicle front side, which is provided in two stages in the vehicle vertical direction, is deformed into a convex shape with a convex T1 toward both outer sides in the vehicle vertical direction by the collision load. However, the second chamber 36B adjacent to the first chamber 36A was not deformed due to the deformation of the first chamber 36A. In other words, when the first chamber 36A was destroyed, the deformation due to destruction was completed within the first chamber 36A.

[0041] FIG. 7 is a diagram schematically showing the analysis result when a collision load is further applied to the front side member 30 of Comparative Example 1 from the state of FIG. 6. As shown in FIG. 7, when a further collision load is applied from the state shown in FIG. 6, the front side member 30 is deformed into a convex shape with convexes T2 and T3 facing both outer sides in the vehicle up-and-down direction in the second room 36B and the third room 36C provided in two stages in the vehicle up-and-down direction, similar to the first room 36A. That is, due to the collision load, the second room 36B and the third room 36C are also deformed by destruction within each room, similar to the first room 36A.

[0042] FIG. 8 is a longitudinal sectional view of the front side member 40 of Comparative Example 2. As shown in FIG. 8, the front side member 40 of Comparative Example 2 is provided with a grooved portion 42 in addition to the configuration of the front side member 30 of Comparative Example 1 shown in FIG. 5. While the minimum rib height H of the grooved portion 22 of the first embodiment is set to be half or more of the width direction dimension D of the upper wall 114 and the lower wall 116 (H≧D / 2), the minimum rib height H2 of the grooved portion 42 of Comparative Example 2 is set to be smaller than the width direction dimension D2 of the upper wall 44 and the lower wall 46 (H2<D2 / 2). Further, the tip of the grooved portion 42 of Comparative Example 2 is pinched into a substantially rectangular shape, and although not shown, the width direction of the grooved portion 42 is narrowed as it goes toward the rear of the vehicle.

[0043] Thus, in the front side member 40 of Comparative Example 2 having a grooved portion 42 pinched more than that of the first embodiment, an analysis was performed by applying a predetermined impact load from the front side of the vehicle in the same manner as the front side member 30 of Comparative Example 1. In Comparative Example 2, since the grooved portion 42 is provided, the impact load required for axial compression of the front side member 40, that is, the crushing load required for crushing each room 36, is smaller compared to Comparative Example 1. In other words, since the front side member 30 of Comparative Example 1 is not provided with the grooved portion 42, the crushing load required for crushing each room 36 is larger compared to Comparative Example 2.

[0044] Fig. 9 is a side view showing a schematic diagram of an analysis result when a collision load is applied to the front side member 40 of Comparative Example 2. As shown in Fig. 9, the first chamber 36A from the vehicle front side, which is provided in two stages in the vehicle vertical direction, is deformed into a convex shape with a convex T1 toward both outer sides in the vehicle vertical direction due to the collision load. In addition, the second chamber 36B adjacent to the first chamber 36A is dragged by the deformation of the first chamber 36A, and the upper wall 44 and the lower wall 46 are deformed toward the outside as shown by the arrow E.

[0045] FIG. 10 is a diagram showing a schematic diagram of an analysis result when a collision load is further applied to the front side member 40 of Comparative Example 2 from the state shown in FIG. 9. As shown in FIG. 10, when a collision load is further applied from the state shown in FIG. 9, the second chamber 36B provided in two stages in the vehicle vertical direction of the front side member 40 is deformed into a concave shape that is convex toward the inside in the vehicle vertical direction (concave P1 toward the outside). Also, the third chamber 36C adjacent to the second chamber 36B is deformed into a convex shape that is convex T2 toward both outsides in the vehicle vertical direction, similar to the first chamber 36A. In Comparative Example 2, different deformations occurred in the order of convex shape, concave shape, and convex shape.

[0046] FIG. 11 is a side view showing a schematic state of the occurrence of residual crush. As shown in FIG. 11, when deformations of different shapes occur in the order of convex T1, concave P1, and convex T2, no residual crush occurs inside the front side member in the vehicle longitudinal direction in the area deformed into convex T1 and T2, as shown by arrow S1. On the other hand, in the area deformed into concave P1, as shown by arrow S2, residual crush may occur due to debris remaining inside the front side member in the vehicle longitudinal direction. When residual crush occurs, the vehicle deformation (stroke) cannot be sufficiently compensated for by the amount of the residual crush, and the energy absorption efficiency of the front side member decreases.

[0047] As described above, in the configuration of the front side member 40 of Comparative Example 2, since a concave deformation occurred, there is a possibility that residual crushing may occur. On the other hand, in the front side member 30 of Comparative Example 1, although a convex deformation occurred, no concave deformation occurred, so residual crushing can be reduced. However, since the front side member 30 of Comparative Example 1 is not provided with a grooved portion, even though the occurrence of residual crushing can be suppressed, the crushing load in each room 36 may become too large, and it may not be possible to ensure the intended energy absorption amount.

[0048] In the front side member 10 of the first embodiment, as shown in FIG. 3, the minimum rib height H of the rib 20 is set to be equal to or greater than half of the width direction dimension D of the upper wall 114 and the lower wall 116 (H≧D / 2). In this way, by adjusting the minimum rib height H, that is, the grooving amount of the grooved portion 22, the crushing load in the room 24 partitioned by the rib 20 can be controlled, so that the intended energy absorption amount can be ensured. Specifically, by making the minimum rib height H higher than that of Comparative Example 2, in other words, by making the grooving amount of the grooved portion 22 smaller than that of Comparative Example 2, the occurrence of concave deformation can be suppressed. Thereby, while reducing the decrease in energy absorption efficiency due to residual crushing, the intended energy absorption amount can be ensured.

[0049] Further, in the front side member 10 of the first embodiment, the minimum rib height H is set to increase toward the rear of the vehicle. That is, the grooving amount of the grooved portion 22 becomes smaller toward the rear of the vehicle. As a result, the crushing load increases from the front side to the rear of the front side member 10 of the vehicle, so that it is easier to crush in order from the front side of the vehicle, and the robustness of the deformation during a collision can be improved.

[0050] Further, according to the front side member 10 of the first embodiment, the cross-sectional shape is a U-shaped cross-sectional shape, and the opening 110 is provided on the outer side in the vehicle width direction, so there is a wall on the inner side in the vehicle width direction. Thereby, it is possible to suppress fragments from flying to, for example, the power unit P disposed on the inner side in the vehicle width direction.

[0051] Furthermore, according to the front side member 10 of the first embodiment, the recessed portion 22 provided on the rib 20 has a tip that is recessed in an arc shape, so that the central portion of the front side member in the vertical direction of the vehicle is more susceptible to crushing, and convex deformation that convexly protrudes outward is more likely to occur on the wall surface in the vertical direction of the vehicle.

[0052] Second embodiment Next, a front side member 10-2 according to a second embodiment of the present invention will be described. Note that the same components as those in the first embodiment are designated by the same reference numerals and will not be described here, and only the different components will be described. Fig. 12 is a perspective view of the front side member 10-2 according to the second embodiment of the present invention as viewed diagonally from the front side of the vehicle, and Fig. 13 is a cross-sectional view taken along line BB in Fig. 12.

[0053] 12 and 13, the front side member 10-2 of the second embodiment has an H-shaped cross section, and has openings 110 provided on the inner side surface 10A and the outer side surface 10B (see FIG. 1) in the vehicle width direction. That is, the front side member 10-2 has a bottom wall 112 in the center in the vehicle width direction, and the outer (left) surface of the bottom wall 112 is a left bottom surface 112AL and the inner (right) surface is a right bottom surface 112AR.

[0054] 13, the front side member 10-2 has a left rib 20L on the outer side (left side) in the vehicle width direction and a right rib 20R on the inner side (right side), with the left rib 20L having a left scooped portion 22L and the right rib 20R having a right scooped portion 22R. In the second embodiment, the height of the lowest position of the combined height of the left rib 20L and the right rib 20R in the vehicle width direction is defined as the rib minimum height H. As in the first embodiment, the rib minimum height H is set to be equal to or more than half the width dimension D, i.e., H≧D / 2.

[0055] Similarly to the first embodiment, the front side member 10-2 has a rib minimum height H that increases toward the rear of the vehicle. In other words, the width of the left and right recessed portions 22L and 22R decreases toward the rear of the vehicle. The tips of the left and right recessed portions 22L and 22R are hollowed out in a circular shape. Note that, in the second embodiment, the tips may be hollowed out in a straight line, similar to the first embodiment.

[0056] In this embodiment, as shown in Fig. 12, the rib 20 has a gouge portion 22 whose tip is gouged out in an arc shape, but the present invention is not limited to this. As in the first embodiment, the tips of the left gouge portion 22L and the right gouge portion 22R of the gouge portion 22-2 may be gouged out in a straight line (see Fig. 4), for example.

[0057] (Effects of the second embodiment) Next, the effects of the second embodiment will be described.

[0058] The front side member 10-2 according to the second embodiment has an H-shaped cross section and has openings 110 provided on the inside and outside in the vehicle width direction, so that a bottom wall 112 is present in the center of the front side member 10-2 in the vehicle width direction. This makes it possible to control the crushing load on both sides of the front side member 10-2 in the vehicle width direction.

[0059] In addition, since the front side member 10-2 according to the second embodiment also has the left rib 20L and the right rib 20R, the crushing load in the chamber 24 partitioned by the left rib 20L and the right rib 20R can be controlled by adjusting the rib minimum height H. Therefore, the intended energy absorption amount can be secured. Specifically, by making the rib minimum height H higher than that of Comparative Example 2, the occurrence of concave deformation can be suppressed. This makes it possible to suppress the accumulation of fragments of cracks caused by the collision load applied to the front side member 10-2 inside the front side member 10, and reduces the decrease in energy absorption efficiency due to the remaining part of the crushed part. As a result, like the first embodiment, the intended energy absorption amount can be secured while reducing the decrease in energy absorption efficiency due to the remaining part of the crushed part.

[0060] Also, in the front side member 10-2 according to the second embodiment, the rib minimum height H is set to increase toward the rear of the vehicle, so that the crushing load increases from the front side of the vehicle toward the rear of the front side member 10. This makes it easier for the front side to crush, improving the robustness of deformation during a collision.

[0061] Furthermore, in the front side member 10-2 according to the second embodiment, the left recessed portion 22L and the right recessed portion 22R have their tips recessed in an arc shape, so that the central portion of the front side member 10-2 in the vertical direction of the vehicle is more likely to collapse, and convex deformation that convexly protrudes outward is more likely to occur on the wall surface in the vertical direction of the vehicle.

[0062] [supplementary explanation] In the above embodiment, the room 24 is provided in one stage in the vertical direction of the vehicle, but the present invention is not limited to this. For example, the room 24 may be provided in two stages as in Comparative Example 1 and Comparative Example 2.

[0063] In the above-described embodiment, the pair of left and right front side members 10, 10-2, the pair of left and right suspension towers 18, and peripheral parts of the pair of left and right suspension towers 18, i.e., the apron upper member 15, the fender apron 16, and the dash panel 17, are integrally molded by aluminum die casting. However, the present invention is not limited to this, and the front side members 10, 10-2 may be molded separately from other members. Furthermore, the material is not limited to aluminum die casting, and may be die cast of a material other than aluminum.

[0064] Although one embodiment of the present invention has been described above, the present invention is not limited to such an embodiment, and one embodiment may be appropriately combined with various modified examples, and the present invention may of course be embodied in various forms without departing from the gist of the present invention. [Explanation of symbols]

[0065] 10, 10-2 Front side member 110 Aperture 112A Bottom 112AL Bottom left side (bottom side) 112AR Bottom right side (bottom side) 114 Upper Wall 114A Bottom side 116 Lower Wall 116A Top 20 Ribs 20R Left Rib (Rib) 20R Right Rib (Rib) 22 Gouging Section 22L Left hollow (hollow) 22R Right hollow (hollow) D Width dimension of upper and lower walls H Rib minimum height

Claims

1. A front side member that extends in a vehicle front-rear direction on both left and right sides in a vehicle width direction, has an open cross-sectional shape with an opening on at least one side in the vehicle width direction, and is integrally molded by die casting, A plurality of ribs are provided which connect the bottom surface on the opposite side to the opening and the lower surface of the upper wall and the upper surface of the lower wall in the vehicle vertical direction, and the ribs have a minimum rib height along the vehicle width direction which is set to be equal to or greater than half of the width direction dimensions of the upper wall and the lower wall, The minimum rib height of the front side member is set higher toward the rear of the vehicle.

2. 2. The front side member according to claim 1, wherein the open cross-sectional shape is a U-shaped cross-sectional shape, and the opening is provided on an outer side in a vehicle width direction.

3. 2. The front side member according to claim 1, wherein the open cross-sectional shape is an H-shape, and the openings are provided on both the inner side and the outer side in the vehicle width direction.

4. 2. The front side member according to claim 1, wherein the rib has a hollow portion whose tip is hollowed out in an arc shape from the opening side toward the vehicle width direction.

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