Vehicle body structure

Abstract

This invention provides a vehicle body structure that enables both improved resistance of the bumper beam to collision loads during small overlap collisions and a reduction in vehicle weight. [Solution] The front body structure 1 is fixed to the front ends 3a of each of the pair of crash cans 3 and includes a bumper beam 5 that extends in the vehicle width direction. The bumper beam 5 has an upper wall 5b, a lower wall 5c and a vertical wall 5a, and has a cross-sectional shape that is open to the front. The upper wall 5b and the vertical wall 5a form an upper ridge line 5f that extends in the vehicle width direction. The lower wall 5c and the vertical wall 5a form a lower ridge line 5g that extends in the vehicle width direction. In the vehicle width direction, within the joining region 5h of the bumper beam 5 where the crash cans 3 are joined, the upper ridge line 5f and the lower ridge line 5g have an upper bulge 5i and a lower bulge 5j that bulge towards the rear of the vehicle.

Description

[Technical Field]

[0001] The present invention relates to a vehicle body structure at a front or rear portion of a vehicle including a bumper beam and crash cans. [Background Art]

[0002] It is required that a front vehicle body structure of a vehicle is configured such that a collision load in the vehicle front-rear direction caused by a collision from the front of the vehicle (hereinafter referred to as a frontal collision) is not transmitted to a vehicle compartment as much as possible upon the frontal collision. In particular, among frontal collisions of vehicles, there is a so-called small overlap collision where a portion of the front face of the vehicle located outward of front side frames in the vehicle width direction collides with an obstacle (such as an oncoming vehicle or a road installation).

[0003] It is desirable that the front vehicle body structure of a vehicle is configured such that when a small overlap collision occurs, a lateral force (a force directed toward a side opposite to the obstacle in the vehicle width direction) is generated at the front portion of the vehicle, the vehicle is laterally displaced in the vehicle width direction such that the front portion of the vehicle moves toward the side opposite to the obstacle in the vehicle width direction, and the collision load can be deflected in the vehicle width direction as much as possible.

[0004] For example, Patent Document 1 discloses a front vehicle body structure that enables lateral displacement of a vehicle by crushing a crash can upon a small overlap collision.

[0005] The front vehicle body structure described in Patent Document 1 includes a pair of front side frames extending in the vehicle front-rear direction, a pair of crash cans fixed to front ends of the front side frames, and a bumper beam made of fiber-reinforced resin with a U-shaped cross-section that is fixed to front ends of the pair of crash cans and extends in the vehicle width direction.

[0006] In a structure equipped with such a crash can, when a collision load is applied to the end of the bumper beam during a small overlap collision, the collision load is transmitted to the crash can before the deformation of the bumper beam progresses, causing the crash can to collapse from the initial stage of the collision. This generates a lateral force at the front of the vehicle, causing the vehicle to shift laterally in the width direction and thus deflecting the collision load in the width direction. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2016-97717 [Overview of the project] [Problems that the invention aims to solve]

[0008] However, in the above structure, since the bumper beam has a U-shaped cross-section, buckling is likely to occur at the upper and lower edges (corners) of the U-shaped cross-section at the vehicle width end of the bumper beam during a small overlap collision. Therefore, the bumper beam may not have the necessary strength to withstand the impact for the crash can to collapse. As a result, during a small overlap collision, the end of the bumper beam buckles in the initial stages of the collision, which may prevent the vehicle from shifting laterally in the vehicle width direction and thus dissipating the impact load in the vehicle width direction.

[0009] Furthermore, if reinforcing members are added to reinforce the bumper beam to suppress buckling at its ends, it becomes difficult to reduce the weight of the vehicle body.

[0010] The present invention has been made in view of the above circumstances, and aims to provide a vehicle body structure that can achieve both improved resistance of the bumper beam to collision loads during small overlap collisions and weight reduction of the vehicle body. [Means for solving the problem]

[0011] To solve the above problems, the vehicle body structure of the present invention comprises a vehicle body structure comprising: a pair of side frames spaced apart from each other in the vehicle width direction and extending in the vehicle longitudinal direction; a pair of crash cans fixed to the front or rear ends of the pair of side frames and extending in the vehicle longitudinal direction; and a bumper beam fixed to the end of each of the pair of crash cans opposite to the side frames and extending in the vehicle width direction, wherein the bumper beam comprises an upper wall and a lower wall spaced apart from each other in the vertical direction and extending in the vehicle width direction, and a vertical wall connecting the ends of the upper wall and the lower wall on the side closer to the crash cans. The bumper beam has a cross-sectional shape that is open to one side in the front-rear direction, formed by the upper wall, lower wall and vertical wall, an upper ridge line extending in the vehicle width direction is formed by the upper wall and the vertical wall, a lower ridge line extending in the vehicle width direction is formed by the lower wall and the vertical wall, the vertical wall of the bumper beam and the crash can are joined so that they face each other in the vehicle front-rear direction, and the upper ridge line and the lower ridge line within the range of the joining area in the vehicle width direction where at least the crash can of the bumper beam is joined have a bulge formed in the direction toward the crash can in the vehicle front-rear direction.

[0012] With this configuration, bulges are formed on both the upper and lower ridges of the bumper beam in the crash can joint region. This allows the bulges to receive and distribute stress at the ridge portion that is the starting point for buckling of the bumper beam during a small overlap collision, thereby improving the rigidity of that ridge portion. Consequently, it becomes possible to ensure the overall rigidity of the bumper beam even without reinforcing members. As a result, it becomes possible to achieve both improved resistance of the bumper beam to collision loads during small overlap collisions and weight reduction of the vehicle body.

[0013] Furthermore, by firmly crushing the crush can during a small overlap collision, the energy absorption effect of the crush can can be improved.

[0014] In the vehicle body structure described above, it is preferable that the bulging portion is formed in a range longer than the width of the crush can in the vehicle width direction.

[0015] With this configuration, the bulge is formed in a range that is longer in the vehicle width direction than the width of the crash can, which prevents buckling of the bumper beam near the outer end of the crash can in the vehicle width direction. Therefore, the rigidity of the bumper beam can be reliably ensured against the bending load acting on the bumper beam during a collision. As a result, the impact can be reliably transmitted to the crash can via the bumper beam, and the crash can reliably collapse to absorb the impact.

[0016] In the vehicle body structure described above, the bulging portion preferably has an arc-shaped cross-section.

[0017] With this configuration, the cross-sectional shape of the bulging portion is composed of curves, making it less likely for cracks to originate in the bulging portion during a collision, and thus ensuring the rigidity of the bumper beam more reliably.

[0018] In the vehicle body structure described above, it is preferable that on both sides of the bulging portion in the vehicle width direction, there are tapered edges that are continuous with the bulging portion and where the amount of bulging gradually decreases as they move away from the bulging portion.

[0019] With this configuration, since tapered edges are formed on both sides of the bulge in the vehicle width direction, stress concentration is less likely to occur on both sides of the bulge in the vehicle width direction during a vehicle collision, thus making it possible to more reliably ensure the rigidity of the bumper beam.

[0020] In the vehicle body structure described above, it is preferable that a recess or groove 5p is formed in the vertical wall of the bumper beam outside the range of the joining region, in a direction that is recessed away from the crash can in the longitudinal direction of the vehicle.

[0021] According to this configuration, outside the range of the joint region of the crash can, a recess or a groove portion 5p is formed in the vertical wall of the bumper beam, so that the rigidity of the bumper beam can be more reliably ensured even without a bulging portion. Effects of the Invention

[0022] According to the vehicle body structure of the vehicle of the present invention, it is possible to achieve both an improvement in the yield strength of the bumper beam against a collision load during a small overlap collision and a weight reduction of the vehicle body. Brief Description of the Drawings

[0023] [Figure 1] It is a perspective view, seen diagonally from the front and above, showing the overall configuration of a front vehicle body structure of a vehicle according to an embodiment of the present invention. [Figure 2] It is a plan view of the front vehicle body structure in Fig. 1. [Figure 3] It is a perspective view of the bumper beam in Fig. 1, seen from the rear of the vehicle and diagonally upper left. [Figure 4] It is a view, seen from the front of the vehicle, of the bumper joint region on the left side of the bumper beam in Fig. 3 and the peripheral portion thereof. [Figure 5] It is a view, seen from the front of the vehicle, of the bumper joint region on the right side of the bumper beam in Fig. 3 and the peripheral portion thereof. [Figure 6] It is a sectional view taken along line VI-VI in Fig. 4. [Figure 7] It is a sectional view taken along line VII-VII in Fig. 5. [Figure 8] It is a view, seen from the rear of the vehicle and upper right, of the bumper joint region on the right side of the bumper beam in Fig. 3, the peripheral portion thereof, and a traction hook mounting socket. [Figure 9] It is a view, seen from the rear of the vehicle and upper right, of a state where a crash can is joined to the bumper joint region on the right side of the bumper beam in Fig. 8. [Figure 10] It is a view, seen from above and the right rear, of a state where a crash can is joined to the bumper joint region on the right side of the bumper beam in Fig. 9. [Figure 11]Figure 3 is a graph showing the relationship between the displacement of the bumper beam and the measured load during a small overlap collision, for the bumper beam of this embodiment shown and a comparative example, a conventional bumper beam without a bulge. [Modes for carrying out the invention]

[0024] A preferred embodiment of the present invention will be described in detail below with reference to the attached drawings. As an example of the vehicle body structure of the present invention, the front vehicle body structure 1 will be described as an example.

[0025] The front body structure 1 of the vehicle in this embodiment, as shown in Figures 1 and 2, is composed of a collection of parts that receive the collision load when colliding with an obstacle (such as an oncoming vehicle or roadside fixture) from the front of the vehicle X1. Specifically, it comprises a pair of front side frames 2, a pair of crash cans 3, and a bumper 4 extending in the vehicle width direction Y, including a bumper beam 5. The bumper beam 5 is fixed to the front ends 3a of each of the pair of crash cans 3 and extends in the vehicle width direction Y.

[0026] In Figures 1-2 and 9, reference numeral 8 indicates a bracket for attaching the radiator shroud.

[0027] As shown in Figure 2, the pair of front side frames 2 are spaced apart from each other in the vehicle width direction Y and extend in the vehicle longitudinal direction X. The front end 2a of the front side frame 2 is provided with a mounting flange 9 for fixing the crash can 3. The rear end of the front side frame 2 is fixed to a vehicle body component such as a hinge pillar (not shown).

[0028] Each of the pair of crash cans 3 is fixed to the front end 2a of each of the pair of front side frames 2 and extends in the longitudinal direction X of the vehicle. The front end 3a of the crash can 3 is fixed to the bumper beam 5 by welding or the like, and a mounting flange 10 is provided at the rear end 3b. The crash can 3 is fixed to the front end 2a of the front side frame 2 by overlapping the mounting flange 10 of the rear end 3b of the crash can 3 with the mounting flange 9 of the front end 2a of the front side frame 2 and connecting the mounting flanges 9 and 10 to each other using fasteners such as bolts.

[0029] As shown in Figures 2 and 3, the bumper beam 5 includes a crash can joining region 5h that is joined to the crash can 3 on both sides in the vehicle width direction Y, and an extension 5r that extends outward in the vehicle width direction Y from the crash can joining region 5h.

[0030] Next, we will explain the details of the configuration of Crash Can 3 and Bumper 4 in order.

[0031] (Composition of Crash Can 3) The crash can 3 has a configuration such that its rigidity in the vehicle's longitudinal direction X is lower than that of the front side frame 2. For example, the crash can 3 has a structure that is easily crushed during a vehicle collision and is made of a cylindrical body, such as a rectangular cross-section, manufactured by press-forming an aluminum plate.

[0032] As shown in Figure 9, the crash can 3 of this embodiment is a cylindrical body that has a cross-sectional shape when viewed from the rear of the vehicle and extends in the longitudinal direction X of the vehicle. The cylindrical body with a cross-sectional shape is formed, for example, by overlapping two parts that are divided in the longitudinal direction. Each divided part is formed by press-forming a metal plate such as steel or aluminum alloy.

[0033] The crash can 3 has four main components that make up a cross-sectional shape: an upper projection 31, a lower projection 32, and a pair of lateral projections 33 and 34 on the left and right sides. As shown in Figures 9-10, the front end 31a of the upper projection 31 protrudes X1 forward from the vertical wall 5a of the bumper beam 5 and is joined to the upper wall 5b of the bumper beam 5 by welding or the like. Similarly, the front end 32a of the lower projection 32 is joined to the lower wall 5c of the bumper beam 5 by welding or the like. The other parts of the crash can 3, namely the parts of the upper projection 31 and lower projection 32 other than the front ends 31a and 32a, and the pair of lateral projections 33 and 34, are joined to the vertical wall 5a of the bumper beam 5 by welding or the like.

[0034] (Bumper 4 configuration) The bumper 4 of this embodiment, shown in Figures 1 and 2, comprises a bumper beam 5, which is the main body of the bumper 4; a front plate 6 attached to the front side X1 of the bumper beam 5; and a tow hook mounting socket 14 that penetrates the bumper beam 5 and the front plate 6. The bumper beam 5 and the front plate 6 are manufactured from a metal sheet material such as steel.

[0035] The bumper beam 5 is positioned to extend in the vehicle width direction Y and is fixed to the front ends 3a of a pair of crash cans 3 by welding or the like at the positions of a pair of crash can joining regions 5h that are spaced apart from each other in the vehicle width direction Y.

[0036] As shown in Figures 3 to 10, the bumper beam 5 is a long member extending in the vehicle width direction Y, with an intermediate region in the vertical direction Z protruding towards the rear of the vehicle X2 and opening towards the front of the vehicle X1, in other words, it has a U-shaped cross-section with flange portions 5d and 5e at the top and bottom.

[0037] More specifically, the bumper beam 5, as shown in Figures 3 to 10, has an upper wall 5b and a lower wall 5c that are spaced apart from each other in the vertical direction Z and extend in the vehicle width direction Y, and a vertical wall 5a that connects the rear end X2 of the upper wall 5b and lower wall 5c, which is the side closer to the crash can 3. The bumper beam 5 has a U-shaped cross-section that is open to the front X1, which is one side in the longitudinal direction X, formed by the upper wall 5b, the lower wall 5c and the vertical wall 5a.

[0038] Furthermore, the upper wall 5b and the vertical wall 5a form an upper ridge line 5f extending in the vehicle width direction Y. And the lower wall 5c and the vertical wall 5a form a lower ridge line 5g extending in the vehicle width direction Y.

[0039] Furthermore, the bumper beam 5 further comprises a pair of flange portions 5d and 5e that constitute the front end portion of the bumper beam 5 (see Figure 3). The pair of flange portions 5d and 5e extend upward from the front end of the upper wall 5b and downward from the front end of the lower wall 5c. These upper wall 5b, vertical wall 5a, lower wall 5c, and the pair of flange portions 5d and 5e constitute the hat-shaped bumper beam 5 as described above.

[0040] As shown in Figures 1 and 2, the front plate 6 is a plate-shaped member extending in the vehicle width direction Y, covering the U-shaped bumper beam 5 from the front of the vehicle X1, and forming a closed cross section together with the bumper beam 5.

[0041] In the vehicle width direction Y, within the left and right joining regions 5h (left joining region 5hL, right joining region 5hR) where at least one pair of crash cans 3 in the bumper beam 5 are joined, upper bulges 5i and lower bulges 5j are formed on the upper ridge 5f and lower ridge 5g, which bulge in the direction toward the crash can 3 in the vehicle longitudinal direction X, i.e., rearward X2.

[0042] In this embodiment, as shown in Figures 3-5, an elongated hole 5n extending in the vehicle width direction Y is formed in the vertical wall 5a within the left and right joining regions 5h (5hL, 5hR), but this is not essential in the present invention. Also, a hole 5s for fitting a socket 14 for attaching a tow hook is formed in the vertical wall 5a within the right joining region 5hR, but this is not essential in the present invention. The hole 5s for attaching the tow hook can be formed at any position on the bumper beam 5.

[0043] In the left and right joining regions 5h of the bumper beam 5, the vertical wall 5a and the front end 4a, which is the leading end of the crash can 3, are joined so that they face each other in the vehicle's longitudinal direction X. In this embodiment, as described above, the crash can 3 is firmly joined to the bumper beam 5 at three locations: the upper wall 5b, the vertical wall 5a, and the lower wall 5c, by welding or the like.

[0044] Since the vertical wall 5a that receives the crush can 3 is flat, it is effective to provide an upper bulge 5i and a lower bulge 5j in order to increase the load-bearing capacity of the joint area 5h including the vertical wall 5a.

[0045] The projection height of the upper bulge 5i and lower bulge 5j extending rearward X2 from the vertical wall 5a is effective in increasing load-bearing capacity if it is, for example, about 3 mm.

[0046] As shown in Figures 3-7 (especially Figures 6-7), the upper bulge 5i and the lower bulge 5j have an arc-shaped cross-section. The radius of curvature (R) of the arc-shaped surfaces of the upper bulge 5i and the lower bulge 5j is set considering conditions such as ease of processing, distance from the traction hook hole 5s, and ensuring that the radius of curvature is of a size that prevents cracking.

[0047] Furthermore, in the right-hand joint region 5hR shown in Figures 5 and 7, the width around the hole 5s is required on the vertical wall 5a in order to ensure that the upper bulge 5i and lower bulge 5j are separated from the hole 5s for attaching the towing hook. Therefore, the radius of curvature (R) of the upper bulge 5i and lower bulge 5j is set taking this width around the hole 5s into consideration.

[0048] By providing the arc-shaped upper bulge 5i and lower bulge 5j, the upper wall 5b and lower wall 5c extend in a direction parallel or nearly parallel to the vehicle's longitudinal direction X (becoming straight). For example, compared to the upper wall 51b and lower wall 51c of the comparative example shown in Figure 7 (i.e., the upper wall 51b and lower wall 51c in a bumper beam without bulges), it can be seen that in this embodiment the upper wall 5b and lower wall 5c extend in a direction nearly parallel (straight) to the vehicle's longitudinal direction X. Furthermore, this increases the area of ​​the closed cross-section of the bumper beam 5, thereby increasing its load-bearing capacity.

[0049] The upper bulge 5i and the lower bulge 5j are formed in a range that is longer than the width W of the crash can 3 (see Figure 9) in the vehicle width direction Y. A longer length for the upper bulge 5i and the lower bulge 5j is preferable in terms of improving the rigidity of the bumper beam 5, and the maximum length may be extended to the total length of the bumper beam 5. However, considering the ease of processing the bumper beam 5, it is sufficient that they are formed in a range that is at least longer than the width W of the crash can 3.

[0050] Furthermore, as shown in Figures 3-5 and 8-9, on both sides of the upper bulge 5i and lower bulge 5j in the vehicle width direction Y, a tapered edge 5k is formed, which is continuous with the upper bulge 5i and lower bulge 5j, and the amount of bulging gradually decreases as it moves away from the upper bulge 5i and lower bulge 5j. The length of the tapered edge 5k on the outside in the vehicle width direction Y may be the same as or shorter than the length of the extension 5r on the outside of the joint area 5h with the crush can 3.

[0051] Furthermore, in this embodiment, a recess or groove 5p is formed in the vertical wall 5a outside the range of the joint area 5h of the bumper beam 5, in a direction that is recessed away from the crash can 3 in the vehicle longitudinal direction X. The range of the groove 5p is limited to a range in the vehicle width direction Y where there is no upper bulge 5i and lower bulge 5j (a range where increased load-bearing capacity due to the bulge 5i and 5j cannot be obtained), and may also be a range that overlaps with the narrow edge 5k and the upper bulge 5i and lower bulge 5j.

[0052] (Features of this embodiment) (1) The front body structure 1 of the vehicle in this embodiment comprises a pair of front side frames 2, a pair of crash cans 3, and a bumper beam 5. The bumper beam 5 has an upper wall 5b and a lower wall 5c, and a vertical wall 5a connecting the rear X2 (side closer to the crash can 3) ends of the upper wall 5b and the lower wall 5c. The bumper beam 5 has a cross-sectional shape that is open to one side in the longitudinal direction X, formed by the upper wall 5b, the lower wall 5c, and the vertical wall 5a. The upper wall 5b and the vertical wall 5a form an upper ridge line 5f extending in the vehicle width direction Y. The lower wall 5c and the vertical wall 5a form a lower ridge line 5g extending in the vehicle width direction Y. The vertical wall 5a of the bumper beam 5 and the crash can 3 are joined so as to face each other in the vehicle longitudinal direction X.

[0053] In this front body structure 1, in the vehicle width direction Y, at least within the joining region 5h of the bumper beam 5 where the crash can 3 is joined, upper bulge 5i and lower bulge 5j are formed on the upper ridge 5f and lower ridge 5g, which bulge in the direction toward the crash can 3 in the vehicle longitudinal direction X, i.e., toward the rear X2 of the vehicle.

[0054] As a result, in the event of a small overlap collision, that is, as shown in Figure 2, when an obstacle collides from the front X1 to the extension 5r that is outside the joint area 5h of the bumper beam 5 in the vehicle width direction Y, and the collision load CF is partially applied to the extension 5r, the bulging portions 5i and 5j can receive and distribute the stress at the ridge portions 5f and 5g, which are the starting points for buckling of the bumper beam 5, thereby improving the rigidity of the ridge portions 5f and 5g. Therefore, it becomes possible to ensure the rigidity of the entire bumper beam 5 even without reinforcing members. As a result, it becomes possible to achieve both improved resistance of the bumper beam 5 to collision loads during small overlap collisions and weight reduction of the vehicle body.

[0055] Furthermore, by firmly crushing Crush Can 3 during a small overlap collision, the energy absorption effect of Crush Can 3 can be improved.

[0056] Here, the effect of the bulging portions 5i and 5j on improving the load-bearing capacity of the bumper beam 5 is verified in the graph of Figure 11. Figure 11 is a graph showing the relationship between the displacement amount in the longitudinal direction X of the bumper beam 5 and the measured load during a small overlap collision for the bumper beam 5 of this embodiment (curve I) shown in Figure 3 and a comparative example, a conventional bumper beam (curve II) that does not have the upper bulging portion 5i and the lower bulging portion 5j.

[0057] Looking at the graph in Figure 11, in curve I, which shows the case of the bumper beam 5 of this embodiment, it can be seen that, due to the presence of bulging portions 5i and 5j, a sufficiently large load (approximately 105kN) can be obtained to crush the crush can 3 with a short displacement (approximately 15mm) during a small overlap collision, compared to curve II, which shows a comparative example without bulging portions. On the other hand, in the comparative example without bulging portions, as shown in curve II, the load only rises to approximately 98kN even with a large displacement (approximately 20mm), so it is not possible to completely crush the crush can 3. Looking at these curves I and II, the load-increasing effect of the bulging portions 5i and 5j is clear.

[0058] (2) In the front body structure 1 of the vehicle of this embodiment, the upper bulge portion 5i and the lower bulge portion 5j are formed in a range that is longer than the width W of the crash can 3 (see Figure 9) in the vehicle width direction Y.

[0059] With this configuration, the upper bulge 5i and the lower bulge 5j are formed in a range that is longer in the vehicle width direction Y than the width of the crash can 3, thereby preventing buckling of the bumper beam 5 near the outer end of the crash can 3 in the vehicle width direction Y. Therefore, the rigidity of the bumper beam 5 can be reliably ensured against the bending load acting on the bumper beam 5 during a collision. As a result, the impact can be reliably transmitted to the crash can 3 via the bumper beam 5, and the crash can 3 can be reliably crushed to absorb the impact.

[0060] (3) In the front body structure 1 of the vehicle of this embodiment, the upper bulge portion 5i and the lower bulge portion 5j have an arc-shaped cross-section, as shown in Figures 6 and 7.

[0061] With this configuration, the cross-sectional shapes of the upper bulge 5i and the lower bulge 5j are curved, making it less likely for cracks to originate in the upper bulge 5i and the lower bulge 5j during a collision, thereby more reliably ensuring the rigidity of the bumper beam 5.

[0062] (4) In the front body structure 1 of the vehicle according to this embodiment, on both sides of the upper bulge portion 5i and the lower bulge portion 5j in the vehicle width direction Y, there are gradual-extension sections 5k (see Figures 3-5) which are continuous with the upper bulge portion 5i and the lower bulge portion 5j, and the amount of bulging gradually decreases as they move away from the upper bulge portion 5i and the lower bulge portion 5j.

[0063] With this configuration, since tapered edges 5k are formed on both sides in the vehicle width direction Y of the upper bulge 5i and the lower bulge 5j, stress concentration is less likely to occur on both sides in the vehicle width direction Y of the upper bulge 5i and the lower bulge 5j during a vehicle collision, thus making it possible to more reliably ensure the rigidity of the bumper beam 5.

[0064] (5) In the front body structure 1 of the vehicle according to this embodiment, a recess or groove 5p (see Figures 3-5) is formed in the vertical wall 5a outside the range of the joining area 5h of the bumper beam 5, in a direction that is recessed away from the crash can 3 in the longitudinal direction X of the vehicle.

[0065] With this configuration, outside the range of the joint area 5h of the crash can 3, a recess or groove 5p is formed in the vertical wall 5a of the bumper beam 5, making it possible to more reliably ensure the rigidity of the bumper beam 5 even without the upper bulge 5i and lower bulge 5j.

[0066] (modified version) In the above embodiment, the crash can 3 and bumper beam 5 are provided at the front ends of the pair of front side frames 2 (side frames), but the present invention is not limited thereto, and the crash can 3 and bumper beam 5 may be provided at the rear ends of the pair of rear side frames. This configuration makes it possible to improve the load-bearing capacity of the bumper beam against collision loads during small overlap collisions from the rear of the vehicle and to reduce the weight of the vehicle body. [Explanation of symbols]

[0067] 1. Front body structure 2 Front side frame 3 Crush Can 4 Bumpers 5. Bumper beam 5a vertical wall 5b Upper wall 5c lower wall 5f Upper ridgeline 5g Lower ridgeline 5h joint area 5i Upper bulge 5j lower bulge 5k Seobyenbu 5p groove 5r extension

Claims

1. The vehicle body structure, A pair of side frames are positioned spaced apart from each other in the width direction of the vehicle and extend in the front-rear direction of the vehicle, A pair of crash cans are fixed to the front or rear end of the pair of side frames and extend in the longitudinal direction of the vehicle, A bumper beam extending in the vehicle width direction is fixed to the end of each of the pair of crash cans opposite to the side frame, Equipped with, The bumper beam has an upper wall and a lower wall that are spaced apart from each other in the vertical direction and extend in the vehicle width direction, and a vertical wall that connects the ends of the upper wall and the lower wall on the side closer to the crash can, and has a cross-sectional shape that is open in one direction in the front-rear direction formed by the upper wall, the lower wall and the vertical wall. The upper wall and the vertical wall form an upper ridge line extending in the vehicle width direction. The aforementioned lower wall and the aforementioned vertical wall form a lower ridge line extending in the vehicle width direction. The vertical wall of the bumper beam and the crash can are joined so that they face each other in the front-rear direction of the vehicle. In the vehicle width direction, the upper and lower ridges of the bumper beam, within the range of the joining area where the crash can is joined, have bulges formed in the vehicle longitudinal direction toward the crash can. A vehicle body structure characterized by the following features.

2. In the vehicle body structure described in claim 1, The bulging portion is formed in a range that is longer than the width of the crush can in the vehicle width direction. A vehicle body structure characterized by the following features.

3. In the vehicle body structure according to claim 1 or 2, The bulging portion has an arc-shaped cross-section. A vehicle body structure characterized by the following features.

4. In the vehicle body structure according to claim 1 or 2, On both sides of the bulging portion in the vehicle width direction, a tapered edge portion is formed that is continuous with the bulging portion and where the amount of bulging gradually decreases as it moves away from the bulging portion. A vehicle body structure characterized by the following features.

5. In the vehicle body structure according to claim 1 or 2, In the bumper beam, the vertical wall outside the range of the joining region has a recess or groove formed in the direction away from the crash can in the vehicle's longitudinal direction. A vehicle body structure characterized by the following features.

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