Vehicle body structure

Abstract

To improve durability while maintaining damping function with a simple configuration on a vehicle body structure.SOLUTION: A vehicle body structure includes: a crash can 10 fitted to a tip of a side member 3; and a projection 16 installed to at least one of the corner parts in the vicinity of the tip on a side of the side member 3 of the crash can 10 and having a projection shape that projects to other parts than the corner parts.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a vehicle body structure formed at an end of a side member of a vehicle. [Background technology]

[0002] Conventionally, a vehicle body structure is known in which crash cans (crash boxes) are arranged at the front and rear ends of a vehicle to reduce the impact of a collision. A crash can is a member that absorbs impact energy by deforming when subjected to the impact of a collision. By attaching crash cans to the front and rear ends of side members, the shock absorbing performance of the vehicle is improved, and the performance of protecting occupants in the vehicle cabin can be improved (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-117159 A Summary of the Invention [Problem to be solved by the invention]

[0004] The above-mentioned shock absorbing member is preferably formed so as to deform moderately while absorbing shock. However, in terms of durability, it is preferable that the shock absorbing member has high rigidity and does not deform easily. Therefore, there is a problem that a vehicle body structure including the shock absorbing member is required to have conflicting characteristics, and it is difficult to achieve both.

[0005] For example, in a vehicle in which a bumper beam is attached to a side member via a crash can, a tie-down hook (towing hook) may be provided on the crash can. The tie-down hook is a part to which a fixing wire is connected when the vehicle is transported on a ship or a land trailer. In this case, since a load acts on the crash can via the tie-down hook, there is a possibility that the crash can may be unintentionally deformed during transportation. On the other hand, if the rigidity of the crash can is increased in order to prevent this deformation, the crash can will be less likely to deform during a collision, and there is a risk that good cushioning performance will not be obtained.

[0006] One of the objectives of the present invention, which was devised in light of the above-mentioned problems, is to provide a vehicle body structure that can improve durability while maintaining a shock-absorbing function with a simple configuration. In addition to this objective, another objective of the present invention is to achieve effects that cannot be obtained with conventional technology, which are derived from the respective configurations shown in the "Description of Embodiments of the Invention" described later. [Means for solving the problem]

[0007] The disclosed vehicle body structure can be realized as the following disclosed aspects or application examples, and solves at least part of the above-mentioned problems. The disclosed vehicle body structure includes a crash can attached to a tip end of a side member, and a protrusion provided at at least one corner near an end of the crash can on the side member side and having a shape that protrudes from the corner to be convex with respect to a portion other than the corner. Effect of the Invention

[0008] According to the disclosed vehicle body structure, it is possible to improve durability while maintaining shock-absorbing function with a simple configuration. [Brief description of the drawings]

[0009] [Figure 1] 1 is a perspective view showing a structure around a crash can in a vehicle to which a vehicle body structure according to an embodiment is applied; FIG. [Diagram 2] 2A is a top view showing the body structure of FIG. 1, and FIG. 2B is a side view thereof. [Diagram 3] 2 is an exploded perspective view of a crash can according to the vehicle body structure of FIG. 1. FIG. [Figure 4] FIG. 4 is an enlarged perspective view of the crash can of FIG. 3. [Diagram 5] FIG. 4 is a cross-sectional view of the crash can of FIG. 3. [Figure 6] 4A is a perspective view of a main part of a crash can as a comparative example, and FIG. 4B is a perspective view of a main part of the crash can in FIG. [Figure 7] FIG. 11 is a cross-sectional view of a crash can according to a modified vehicle body structure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] [1. Configuration] A vehicle body structure 1 as an embodiment is applied to a vehicle 2 shown in FIG. 1. A pair of left and right side members 3 extending in the front-rear direction and spaced apart in the vehicle width direction are provided inside the vehicle 2. The side members 3 are cylindrical structural members, and are formed, for example, with a substantially rectangular cross section. A bumper beam 7 extending in the vehicle width direction is attached to the tip ends (front end and rear end) of the side members 3 via crash cans 10. The crash cans 10 are cylindrical members that absorb impact energy by deforming when subjected to impact during a collision. Hereinafter, in this embodiment, the vehicle body structure 1 on the front side of the vehicle 2 will be described in detail.

[0011] FIG. 2(A) is a top view of the vehicle body structure 1 of FIG. 1, and FIG. 2(B) is a side view thereof. The crash cans 10 are provided at the front end portions of the left and right side members 3. Each crash can 10 is formed, for example, in a hollow rectangular prism shape, and is arranged in the same straight line as each side member 3. In this case, the outer surface of the crash can 10 in the vehicle width direction is arranged on substantially the same plane as the outer surface of the side member 3 in the vehicle width direction. Also, the inner surface of the crash can 10 in the vehicle width direction is arranged on substantially the same plane as the inner surface of the side member 3 in the vehicle width direction. As a result, the crash can 10 and the side member 3 are laid out in a linear manner in top view as shown in FIG. 2(A). Note that the height dimension of the crash can 10 can be formed shorter than the height dimension of the side member 3. Therefore, as shown in FIG. 2(B), the upper and lower surfaces of the crash can 10 and the side member 3 are not necessarily linearly connected in side view.

[0012] Between the side member 3 and the crash can 10 shown in FIG. 1, a headlamp support 4 extending in the up-down direction is provided. The headlamp support 4 is, for example, a plate-like member arranged so that the plate surface faces the front-rear direction of the vehicle 2, and has a shape (C-shaped cross section) in which the end in the vehicle width direction is bent toward the rear of the vehicle 2. The front end of the side member 3 is fixed to the plate surface of the headlamp support 4 that faces the rear side of the vehicle 2. The crash can 10 is fixed to the plate surface of the headlamp support 4 that faces the front side of the vehicle 2 via a plate-like plate 8. The plate 8 is a plate-like member to which the end of the crash can 10 is fixed by arc welding and which is fastened and fixed to the headlamp support 4. The plate 8 is formed, for example, in the shape of a rectangular plate.

[0013] The headlamp supports 4 are provided at the front ends of the left and right side members 3. The upper ends of the left and right headlamp supports 4 are connected in the vehicle width direction by an upper bar 5. The upper bar 5 is a member for supporting the bonnet hood, and is disposed, for example, along the edge of the opening to which the bonnet hood is attached. Meanwhile, the lower ends of the left and right headlamp supports 4 are connected in the vehicle width direction by a lower cross member 6.

[0014] A bumper beam 7 extending in the vehicle width direction is attached in front of the left and right crash cans 10. The bumper beam 7 shown in Fig. 1 is the front bumper of the vehicle 2, but a similar bumper is also provided on the rear side. A resin bumper cover (bumper fascia) that forms the exterior of the front end part of the vehicle 2 is attached in front of the bumper beam 7 via a bracket (not shown).

[0015] An eyebolt 9 that functions as a tie-down hook can be attached near the connection point between the bumper beam 7 and the crash can 10. The eyebolt 9 is a member that is fastened and fixed to the crash can 10 to connect a fixing wire when the vehicle 2 is transported, for example, by ship or land trailer. Note that this eyebolt 9 may be removed after the vehicle 2 is transported, or may be left attached.

[0016] 3 is an exploded perspective view showing the structure of the crash can 10. The crash can 10 of this embodiment is provided with an outer member 11, an inner member 12, a cover member 13, a female screw member 14, and a base member 15. The outer member 11 is a member having a U-shaped cross section, and is a plate-like member arranged so that the plate surface faces the vehicle width direction, and has a shape in which the upper and lower ends are bent inwardly of the vehicle 2. The inner member 12 is a member that forms a closed cross-sectional structure by combining with the outer member 11. The shape of the inner member 12 is formed into a plane that closes the inner side of the outer member 11 in the vehicle width direction.

[0017] The upper and lower surfaces of the outer member 11 are provided with mountain folds 21 formed in a mountain-like protruding shape (ridge-like) when the crash can 10 is viewed from the outside. Meanwhile, the side surfaces of the outer member 11 and the inner member 12 are provided with valley folds 22 formed in a valley-like depressed shape (valley-like) when the crash can 10 is viewed from the outside. These mountain folds 21 and valley folds 22 are arranged so that both ends are connected to each other. By providing these mountain folds 21 and valley folds 22 on the crash can 10, the crash can 10 becomes more likely to bend and deform along the mountain folds 21 and valley folds 22 during a collision, and the deformed shape is optimized, improving the efficiency of absorbing impact energy.

[0018] The cover member 13 is a planar member that covers the entire front end portion of the crash can 10. The front side of the cover member 13 is attached so as to contact the rear side of the bumper beam 7, and the rear side of the cover member 13 is attached so as to contact the front end edges of the outer member 11 and the inner member 12. An opening into which the eyebolt 9 can be inserted is also drilled in the cover member 13, and a female screw member 14 is fixed inside the opening.

[0019] The female screw member 14 is a shaft-shaped member having a female screw formed therein to screw into the eyebolt 9. The front end surface of the female screw member 14 is fixed to the rear surface side of the cover member 13. In addition, a base member 15 is fixed to the rear end surface of the female screw member 14. The base member 15 is a plate-shaped member that is attached to the inside of the crash can 10. The four sides of the base member 15 are fixed to the inside of the outer member 11 and the inner member 12.

[0020] The female thread member 14 and the base member 15 are preferably formed to a size that does not impair the cushioning performance of the crash can 10. For example, if the vehicle length dimension of the female thread member 14 is too large, the crush allowance of the crash can 10 will be small, so it is preferable to make it shorter than the vehicle length dimension of the crash can 10. Furthermore, when fixing the base member 15 to the inside of the crash can 10, it is preferable to fix it by spot welding or spot welding.

[0021] A plate 8 is welded and fixed to the rear end portion of the crash can 10 so as to cover the entire rear end portion. The welding between the crash can 10 and the plate 8 is, for example, fillet welding in which a bead is formed at the inside corner where these members abut. In addition, bolt holes 20 are drilled in the four corners of the plate 8 to serve as fastening points through which fasteners such as bolts and rivets are inserted. Correspondingly, similar bolt holes are drilled in the headlamp support 4. The bolt holes 20 are located outside the crash can 10 relative to the welded points.

[0022] FIG. 4 is an enlarged perspective view of the crash can 10 disposed on the left side of the vehicle 2. A protrusion 16 is provided near the end of the crash can 10 facing the side member 3. The protrusion 16 is a portion of the outline of the crash can 10 that protrudes outward. Here, "outward" refers to the direction in which the cross-sectional area of ​​the crash can 10 increases. The protrusion 16 is provided at least at one of the corners of the crash can 10. In the case of a hollow rectangular prism-shaped crash can 10, the protrusion 16 is provided at least at one of the four corners.

[0023] The shape of the protrusion 16 is a shape that protrudes so as to be convex with respect to the surface of the crash can 10 except for the corner where the protrusion 16 is provided. Preferably, the protrusion 16 is provided at least in one of the four corners located on the outer side in the vehicle width direction. The protrusion 16 shown in FIG. 4 is provided at a corner located on the outer side and upper side in the vehicle width direction among the four corners of the crash can 10. When the protrusion 16 is provided on the side surface of the outer member 11, the shape of the protrusion 16 is a shape that protrudes at least outward in the vehicle width direction. Also, when the protrusion 16 is provided on the upper surface of the outer member 11, the shape of the protrusion 16 is a shape that protrudes at least upward. The shape of the protrusion 16 may be formed to protrude outward and upward in the vehicle width direction.

[0024] As shown in FIG. 4, the protruding portion 16 of this embodiment is formed in a polyhedral shape having a top surface portion 17, a first inclined surface portion 18, and a second inclined surface portion 19. The top surface portion 17 is a portion formed in a planar shape and disposed substantially vertically. The top surface portion 17 is formed substantially parallel to the side surface of the outer member 11. The first inclined surface portion 18 is an inclined surface adjacent to the front of the vehicle 2 with respect to the position of the top surface portion 17 as a reference, and is formed in a shape inclined in the front-rear direction of the vehicle 2. On the other hand, the second inclined surface portion 19 is an inclined surface adjacent to the lower side with respect to the position of the top surface portion 17 as a reference, and is formed in a shape inclined in the up-down direction. These first inclined surface portion 18 and second inclined surface portion 19 smoothly connect between the side surface of the outer member 11 and the top surface portion 17.

[0025] Fig. 5 is a cross-sectional view of the crash can 10. In Fig. 5, not only the cross sections of the outer member 11 and the inner member 12 but also the welded portions between the crash can 10 and the plate 8 are highlighted with hatching. An upper welded portion 23 (first welded portion), an outer welded portion 24 (second welded portion), an inner welded portion 25, and a lower welded portion 26 are provided around the periphery of the crash can 10. These four welded portions 23 to 26 are formed along the outer edge of the crash can 10.

[0026] The upper weld 23 is a portion where the upper surface of the outer member 11 (one side surface of the crash can 10) and the plate 8 are welded, and the outer weld 24 is a portion where the side surface of the outer member 11 (the other side surface adjacent to the one side surface of the crash can 10) and the plate 8 are welded. The upper weld 23 and the outer weld 24 are arranged on either side of the protrusion 16. The inner weld 25 is a portion where the inner member 12 and the plate 8 are welded, and the lower weld 26 is a portion where the lower surface of the outer member 11 and the plate 8 are welded. The upper weld 23 and the outer weld 24 are provided to avoid the corners where the upper surface and the side surface of the outer member 11 are connected, and are not connected to each other. Similarly, the outer weld 24 and the lower weld 26 are also provided to avoid the corners where the lower surface and the side surface of the outer member 11 are connected, and are not connected to each other.

[0027] FIG. 6(B) is an enlarged perspective view of the periphery of the protruding portion 16 in the crash can 10 of this embodiment, and FIG. 6(A) is a comparative example showing a state where the protruding portion 16 is not present. Here, the distance from the left end (the outer end in the vehicle width direction, the end on the right side in the figure) of the upper welded portion 23 to the nearest bolt hole 20 is called L1, and the distance from the upper end of the outer welded portion 24 to the nearest bolt hole 20 is called L2. In this embodiment, the protruding portion 16 is provided as shown in FIG. 6(B), and the distance L1 is set to the same dimension as the distance L2. Here, "same" includes not only a state where the distance L1 and the distance L2 are completely the same, but also a state where they are slightly different, for example, a state where the difference between the distance L1 and the distance L2 is several tens of percent or less with respect to either the distance L1 or the distance L2 (a state where the difference is relatively small).

[0028] 6(A), without the protrusion 16, one of the distances L1 and L2 may be larger than the other depending on the position of the bolt hole 20. In the example of FIG. 6(A), the left end of the upper weld 23 is too close to the bolt hole 20, so the distance L1 is shorter than the distance L2. As a result, in terms of shipping resistance, the stress acting on the left end of the upper weld 23 becomes excessively large compared to the upper end of the outer weld 24, and good durability cannot be obtained.

[0029] To address this issue, by providing protrusion 16 as shown in Fig. 6(B), there is a margin for adjusting the welding position and welding length of upper welded portion 23 and outer welded portion 24, making it easy to weld upper welded portion 23 and outer welded portion 24 so that distance L1 and distance L2 are the same. This makes it possible to make the stress acting on the upper end portion of outer welded portion 24 and the stress acting on the left end portion of upper welded portion 23 approximately equal in terms of shipping resistance, thereby achieving good resistance strength.

[0030] [2. Actions and Effects] (1) The vehicle body structure 1 of this embodiment is provided with a crash can 10 and a protruding portion 16. The crash can 10 is attached to the tip end of the side member 3. The protruding portion 16 is provided on at least one of the corners near the end of the crash can 10 on the side member 3 side. In addition, the protruding portion 16 has a shape that protrudes so as to be convex with respect to portions excluding the corner portion.

[0031] In this way, by providing the protrusion 16 at least one of the corners of the crash can 10, the adjustment margin for the welding of the crash can 10 can be increased, and for example, it becomes easy to widen the welding range or change the welding length. As a result, in terms of shipping durability, the stress acting on the welded portion extending horizontally from the corner (upper welded portion 23) and the stress acting on the welded portion extending vertically (outer welded portion 24) can be made approximately equal, preventing stress concentration. Therefore, the durability of the crash can 10 can be improved while maintaining its cushioning function with a simple configuration.

[0032] (2) As shown in Fig. 4, the protruding portion 16 of this embodiment is formed in a multifaceted shape having a first inclined surface portion 18 inclined in the front-rear direction of the vehicle 2 and a second inclined surface portion 19 inclined in the up-down direction. By forming the protruding portion 16 in a multifaceted shape, the rigidity around the protruding portion 16 can be increased. This makes it possible to prevent damage to the crash can 10 when a large load is applied, for example, when the vehicle is towed by a towing hook after the wheel derails.

[0033] (3) The protruding portion 16 in this embodiment is provided at at least one of the corners located on the outer side in the vehicle width direction and has a shape that protrudes outward in the vehicle width direction. This makes it possible to suppress an increase in the cross section of the crash can 10 compared to a case in which the entire surface on the outer side in the vehicle width direction protrudes outward in the vehicle width direction, and therefore makes it possible to efficiently absorb impact without inhibiting deformation during a collision.

[0034] (4) In this embodiment, the protrusions 16 are provided at corners located on the outer side and upper side in the vehicle width direction, as shown in Fig. 4. This minimizes an increase in the cross section of the crash can 10, and allows the crash can to absorb impact more efficiently without hindering deformation during a collision.

[0035] (5) The vehicle body structure 1 of this embodiment is provided with a headlamp support 4 fixed to an end of a side member 3, and a plate 8 fastened to the headlamp support 4. An end of a crash can 10 is welded to the plate 8. The protruding portion 16 has a shape that protrudes in a direction approaching the nearest bolt hole 20 to which a bolt is fastened. This makes it easy to weld the crash can 10 so as to reduce the difference between the distance L1 and the distance L2, as shown in Figs. 6(A) and (B), and the stress acting on the welded portion can be distributed almost evenly. Therefore, good durability can be obtained, and shipping durability can be improved.

[0036] (6) The vehicle body structure 1 of this embodiment is provided with an upper welded portion 23 (first welded portion) and an outer welded portion 24 (second welded portion). The upper welded portion 23 is a portion for welding a joint between the upper surface, which is one side surface of the crash can 10, and the plate 8. The outer welded portion 24 is a portion for welding a joint between the other side surface (outer surface) of the crash can adjacent to the one side surface across the protrusion 16 and the plate 8. Here, the distance L1 from the left end, which is the end on the protrusion 16 side, of the upper welded portion 23 to the nearest fastening point (bolt hole 20) is set to be the same as the distance L2 from the upper end, which is the end on the protrusion 16 side, of the outer welded portion 24 to the nearest fastening point (bolt hole 20). This makes it possible to align the stress acting on the left end of the upper welded portion 23 and the stress acting on the upper end of the outer welded portion 24, and to prevent stress concentration on either one of them. Therefore, the shipping durability strength of the vehicle 2 can be increased.

[0037] (7) In the vehicle body structure 1 of this embodiment, as shown in Fig. 2(A), the outer and inner surfaces in the vehicle width direction of the crash cans 10 are disposed on the same plane as the outer and inner surfaces in the vehicle width direction of the side members 3, respectively. This allows the crash cans 10 to reliably buffer the impact input to the side members 3 during a collision, thereby improving the protection of occupants in the vehicle cabin.

[0038] [3.Other] The above embodiment is merely an example, and there is no intention to exclude the application of various modifications and techniques not specified in the present embodiment. Each configuration of the present embodiment can be modified in various ways without departing from the spirit of the embodiment, and can be selected or combined as necessary. For example, the above embodiment illustrates a structure in which the crush can 10 is welded along its outer edge. On the other hand, depending on the penetration of the molten metal at the weld start and end, the actual welded portion may be shorter than the apparent welded portion. In this case, even if the distances L1 and L2 shown in FIG. 6(B) appear to be the same, there is a risk of bias in the stress during actual transportation.

[0039] Therefore, as shown in FIG. 7, the influence of the degree of penetration at the weld start and end may be reduced by forming extra length portions 27, 28 at the ends of the upper weld portion 23 and the outer weld portion 24. That is, when welding the upper weld portion 23, the first extra length portion 27 is extended from the left end of the upper weld portion 23 toward the end of the plate 8 (upward). Similarly, when welding the outer weld portion 24, the second extra length portion 28 is extended from the upper end of the outer weld portion 24 toward the end of the plate 8 (leftward, rightward in the figure). The extended first extra length portion 27 and second extra length portion 28 function as so-called sacrificial weld portions. This stabilizes the degree of penetration of the molten metal at the A and B parts in FIG. 7, improving the welding quality. Therefore, stress concentration during transportation can be more reliably prevented.

[0040] In addition, in the above embodiment, the vehicle body structure 1 on the front side of the vehicle 2 has been described in detail, but a similar structure can also be applied to the rear side of the vehicle 2. In this case, by forming the protrusions 16 on the crash cans 10 provided at the rear ends of the side members 3, a vehicle body structure that achieves the same effects as those of the above embodiment can be realized. [Explanation of symbols]

[0041] 1. Body structure 2 Vehicles 3 Side members 4 Headlamp Support 5. Upper Bar 6 Lower cross member 7 Bumper Beam 8 Plate 9 Eyebolt 10 Crash Can 11 Outer member 12 Inner member 13 Cover member 14 Female thread member 15 Base material 16 Protrusion 17 Top part 18 First slope section 19 Second slope section 20 Bolt holes (fastening points) 21 Mountain fold 22 Valley fold 23 Upper weld (first weld) 24 Outer weld (second weld) 25 Inner Weld 26 Lower weld 27 First extra length part (extra length part) 28 Second extra length part (extra length part)

Claims

1. A crash can attached to the tip of the side member; a protruding portion provided at at least one corner portion near an end portion of the crash can on the side member side, the protruding portion having a shape protruding so as to be convex with respect to a portion other than the corner portion; A vehicle body structure comprising:

2. The protruding portion is formed in a polyhedral shape having a first inclined surface portion inclined in the vehicle front-rear direction and a second inclined surface portion inclined in the up-down direction. The vehicle body structure according to claim 1 .

3. The protruding portion is provided at least on one of the corners located on an outer side in the vehicle width direction and has a shape protruding outward in the vehicle width direction.

3. The vehicle body structure according to claim 1 or 2.

4. The protruding portion is provided at the corner portion located on the outer side and upper side in the vehicle width direction. The vehicle body structure according to claim 3 .

5. a headlamp support fixed to an end of the side member; a plate to which an end of the crash can is welded and which is fastened to the headlamp support, The protruding portion has a shape that protrudes in a direction approaching a fastening point of the plate. The vehicle body structure according to any one of claims 1 to 4.

6. A first welding portion that welds a joint portion between one side surface of the crash can and the plate; A second welding portion is provided for welding a joint portion between the plate and another side surface of the crash can adjacent to the one side surface across the protrusion, The distance from the end of the first welded portion on the protruding portion side to the nearest fastening point is substantially the same as the distance from the end of the second welded portion on the protruding portion side to the nearest fastening point. The vehicle body structure according to claim 5 .

7. The plate has an excess portion extending from each end of the first welded portion and the second welded portion toward an end of the plate in order to move the end positions of the first welded portion and the second welded portion. The vehicle body structure according to claim 6 .

8. The outer surface and the inner surface of the crash can in the vehicle width direction are disposed on the same plane as the outer surface and the inner surface of the side member in the vehicle width direction, respectively. The vehicle body structure according to any one of claims 1 to 7.

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