Vehicle body structure

Abstract

To provide a vehicle body structure that can ensure the strength of a cross member irrespective of a form of a lateral collision, and that is useful in inhibiting deformation of a vehicle body.SOLUTION: At a time of a lateral collision, when a seat cross member 18 and a floor panel 12 are about to be folded upward, upper ends of a pair of side wall parts 2004 of a reinforcement member 20 abut on an undersurface of an upper wall part 1806 of the seat cross member 18. Accordingly, further deformation in an upward holding direction of the seat cross member 18 is inhibited. At a time of the lateral collision, when the seat cross member 18 and the floor panel 12 are about to be deformed or folded downward, a corner of a first bead 26 of the floor panel 12 is locked in second beads 28 of the pair of lateral wall parts 2004 of the reinforcement member 20. Accordingly, further deformation in a downward folding direction of the seat cross member 18 is inhibited.SELECTED DRAWING: Figure 3

Description

[Technical Field]

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

[0002] Various types of vehicle side impact tests are known, such as pole side impact tests and barrier side impact tests. For example, the pole side impact test involves crashing the side of the front seat of the vehicle being tested into a pole that resembles a utility pole. For example, the barrier side impact test involves colliding a barrier (aluminum honeycomb) that resembles the front of a vehicle with the side of the front seat of the vehicle being tested. FIG. 5 is a schematic diagram illustrating the different ways in which the seat cross member 18 bends as it deforms during a crash test, as viewed from the front of the vehicle. In the figure, the symbol 18 denotes a seat cross member that is provided on a floor panel (not shown) and extends in the vehicle width direction, and the symbol 14 denotes a pair of side sills that are connected to both sides of the floor panel in the vehicle width direction and both ends of the seat cross member 18. Figure 5(A) shows the state before the crash test. FIG. 5(B) shows a state in which the seat cross member 18 has been bent upward, with a convex shape at approximately the center, due to a pole side collision test. The seat cross member 18 bends upward because the direction of the collision load applied to the seat cross member 18 from the pole P extending in the vertical direction is substantially the same as the extension direction of the cross member. FIG. 5C shows that a portion of the seat cross member 18 near the end on the impact side has been bent downwards, resulting in a downward convexity, after a barrier side impact collision test. The seat cross member 18 bends downward because the barrier B collides with a part of the vehicle body above the seat cross member 18, and the direction of the collision load applied from the barrier B to the seat cross member 18 is from above to diagonally downward relative to the extension direction of the seat cross member 18.

[0003] In order to suppress deformation of the vehicle body in such a side collision, cited document 1 discloses a vehicle body structure in which both ends of two adjacent seat cross members 18 are connected to a pair of side sills 14 (rockers), and the ends of the two cross members are connected to each other with a bridging member, and then the ends of the two cross members are connected to the side sills 14 via the bridging member. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2020-83033 Summary of the Invention [Problem to be solved by the invention]

[0005] However, while the conventional configuration shown in Patent Document 1 can ensure strength in the event of a pole side collision, where the direction of the collision load applied from the pole P to the cross member is approximately aligned with the extension direction of the cross member, it does not take into consideration ensuring strength in the event of a barrier side collision, where the direction of the collision load applied from the barrier B to the seat cross member 18 is directed diagonally downward from above relative to the extension direction of the seat cross member 18. The present invention has been made in consideration of the above circumstances, and aims to provide a vehicle body structure that can ensure the strength of the cross member regardless of the type of side collision and is advantageous in suppressing deformation of the vehicle body. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, one embodiment of the present invention is a vehicle body structure in which a cross member extending in the vehicle width direction is provided on the upper surface of a floor panel, the cross member having a front wall portion and a rear wall portion facing each other in the fore-and-aft direction of the vehicle, and an upper wall portion connecting the upper ends of the front wall portion and the rear wall portion, wherein a reinforcing member extending along the extension direction of the cross member is provided inside the cross member, the reinforcing member having a bottom wall portion attached to the floor panel and a pair of side wall portions that rise from the front and rear ends of the bottom wall portion in the fore-and-aft direction of the vehicle and extend to the vicinity of the upper wall portion of the cross member, and a first bead facing the side wall portions is provided at a position near the floor panel on the front wall portion and the rear wall portion of the cross member, or at a position near the front wall portion and the rear wall portion of the floor panel, and a second bead is provided on the pair of side wall portions. In addition, one embodiment of the present invention is characterized in that the cross member has a pair of vertical width change sections where the vertical width suddenly changes at locations near both ends in the extension direction, the reinforcing member extends across the pair of vertical width change sections, and the first bead and the second bead are provided at locations where the reinforcing member straddles each of the vertical width change sections. Furthermore, one embodiment of the present invention is characterized in that a pair of side members extending in the fore-and-aft direction of the vehicle are arranged, and the pair of suddenly changing portions in upper and lower widths are formed inward in the vehicle width direction from the side members. In one embodiment of the present invention, the cross member is a seat cross member. [Effects of the Invention]

[0007] According to one embodiment of the present invention, when the cross member and floor panel attempt to fold upward during a side collision, the cross member is crushed from above at the center of the cross member's extension direction and the center of the floor panel's width direction. As a result, the upper ends of the pair of side walls of the reinforcing member abut the lower surface of the upper wall of the cross member. When the upper ends of the pair of side walls abut the lower surface of the upper wall of the cross member, further deformation of the cross member in the upward bending direction is suppressed. This ensures the strength of the cross member during a side collision, which is advantageous in suppressing deformation of the vehicle body. In addition, during a side collision different from the above, when a collision load is applied diagonally downward relative to the direction of extension of the cross member, causing the cross member and floor panel to deform so as to bend downward, the front and rear walls of the cross member, where they are joined to the floor panel, deform in a direction toward each other (closing direction) in response to the deformation of the floor panel, while the upper ends of the pair of side walls of the reinforcing member deform in a direction away from each other (opening direction) in response to the deformation of the floor panel. As a result, when the corners of the first bead of the floor panel or cross member engage with the second bead of the pair of side walls of the reinforcing member, further deformation of the cross member in the downward bending direction is suppressed. This ensures the strength of the cross member during a side collision, which is advantageous in suppressing deformation of the vehicle body. As a result of the above, the strength of the cross member can be ensured regardless of the type of side collision, which is advantageous in suppressing deformation of the vehicle body. In addition, by providing the first bead and the second bead at a location straddling a pair of sudden changes in vertical width where the vertical width of the cross member suddenly changes near both ends in the extension direction of the cross member, the strength of the cross member can be ensured in the event of a side collision with the barrier, which is advantageous in suppressing deformation of the vehicle body. In addition, by forming the pair of sudden changes in vertical width further inward in the vehicle width direction than the pair of side members arranged extending in the fore-and-aft direction of the vehicle, the strength of the cross member can be ensured more efficiently, which is advantageous in suppressing deformation of the vehicle body. Furthermore, if the cross member is a seat cross member, it is advantageous in suppressing deformation of the seat cross member in the event of a side collision in which the collision load is input near the seat cross member, thereby strengthening the strength of the seat cross member and suppressing deformation of the vehicle body. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a perspective view showing a vehicle body structure according to an embodiment. [Figure 2] FIG. 2 is a view taken along the arrow A in FIG. [Figure 3] FIG. 3 is a cross-sectional view taken along line BB in FIG. 2. [Figure 4] FIG. 4 is a cross-sectional view taken along line CC in FIG. [Figure 5] 1A and 1B are explanatory diagrams illustrating the deformation of a seat cross member due to a side collision, in which (A) shows the state before the side collision, (B) shows the state after a side collision with a pole as an example, and (C) shows the state after a side collision with a barrier as an example. DETAILED DESCRIPTION OF THE INVENTION

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A vehicle body structure according to an embodiment of the present invention will now be described with reference to the drawings. In the following drawings, the symbol FR indicates the front of the vehicle, the symbol UP indicates the upper side of the vehicle, and the symbol LH indicates the width direction of the vehicle. As shown in FIGS. 1 and 2, a vehicle 10 includes a floor panel 12, a pair of side sills 14, a pair of side members 16, two seat cross members 18, and a reinforcing member 20.

[0010] The pair of side members 16 each have a closed cross-sectional structure and are provided to extend in the front-rear direction of the vehicle at a distance from each other in the vehicle width direction. The pair of side sills 14 each have a closed cross-sectional structure and are provided on the outer sides of the pair of side members 16 in the vehicle width direction, extending in the vehicle front-rear direction.

[0011] The floor panel 12 extends in the longitudinal direction and width direction of the vehicle on a pair of side members 16, and the vehicle interior is formed above the floor panel 12. As shown in FIG. 2, the floor panel 12 includes a floor tunnel 22 and a floor portion 24. The floor tunnel 22 extends in the longitudinal direction of the vehicle 10 at the center in the vehicle width direction, and has a cross section that is convex upward and open downward. The floor portions 24 are located on both sides of the floor tunnel 22 in the vehicle width direction. Each floor section 24 has an upper wall section 24A that is located at a lower position than the floor tunnel 22 and continues to the floor tunnel 22, an intermediate wall section 24B that is located at a position suddenly lower than the upper wall section 24A and joined to the seat cross member 18, and a lower wall section 24C that is located at a lower position than the intermediate wall section 24B.

[0012] The two seat cross members 18 are provided on the upper surface of the floor panel 12 at positions closer to the front of the vehicle and spaced apart in the longitudinal direction of the vehicle. As shown in Figures 3(A) and 4(A), each seat cross member 18 has a front wall portion 1802 and a rear wall portion 1804 that face each other in the fore-and-aft direction of the vehicle, and an upper wall portion 1806 that connects the upper ends of the front wall portion 1802 and the rear wall portion 1804, and extends in the vehicle width direction. As shown in FIG. 2, the upper wall portion 1806 extends in the vehicle width direction at a uniform height up to above the pair of side members 16; in other words, the upper end of the seat cross member 18 extends in the vehicle width direction at a uniform height. As shown in Figure 3(A), flanges 1810 protruding away from each other are provided at the lower ends of the front wall portion 1802 and the rear wall portion 1804, and these flanges 1810 are joined to the upper surface of the floor panel 12; therefore, the front wall portion 1802 and the rear wall portion 1804 are attached to the floor panel 12; in other words, the lower end of the seat cross member 18 is attached to the floor panel 12. The seat cross member 18 is joined to the floor panel 12 to form a closed cross-sectional structure. At locations near both ends of the floor panel 12 in the vehicle width direction, there are provided intermediate wall portions 24B and lower wall portions 24C whose vertical widths change suddenly relative to the upper wall portion 1806, so that a pair of vertical width sudden change portions 24D where the vertical width of the seat cross member 18 changes suddenly are provided at locations near both ends of the extension direction of the seat cross member 18, more inward in the vehicle width direction than the side members 16. Both ends of each seat cross member 18 in the extending direction are joined to the inner side surfaces of the pair of side sills 14 in the vehicle width direction. The two seat cross members 18 are the points at which the driver's and passenger's legs attach at the front of the vehicle 10 .

[0013] The vehicle body structure described above is provided with a reinforcing member 20, a first bead 26, and a second bead 28. As shown in Figure 2, the reinforcing member 20 extends inside the seat cross member 18 along the extension direction of the seat cross member 18, and in this embodiment, the reinforcing member 20 extends across a pair of vertical width sudden change portions 24D. As shown in Figures 3(A) and 4(A), the reinforcing member 20 has a bottom wall portion 2002 attached to the floor panel 12 and a pair of side wall portions 2004 that stand up from the front and rear ends of the bottom wall portion 2002 in the fore-and-aft direction of the vehicle, and has a generally U-shape that is open at the top. As shown in Figures 3(A) and (B), in the center of the extension direction of the seat cross member 18, the upper ends of a pair of side wall portions 2004 extend close to the upper end of the seat cross member 18 and are formed opposite each other with a predetermined gap between them, so that they can abut against the upper wall portion 1806 of the seat cross member 18 in the event of a side collision. The first bead 26 and the second bead 28 are provided at locations where the reinforcing member 20 straddles each of the vertical width-changing portions 24D. In other words, the reinforcing member 20 extends outward in the vehicle width direction beyond each of the vertical width-changing portions 24D. As shown in Figure 4(A), the first bead 26 is provided on both sides of the seat cross member 18 in the extension direction, near the front wall portion 1802 and the rear wall portion 1804 of the floor panel 12, so as to face the side wall portion 2004, respectively. As shown in FIGS. 4(A) and 4(B), the pair of side wall portions 2004 are provided with second beads 28 that engage with the first beads 26 in the event of a side collision. The first beads 26 may be provided at locations closer to the floor panel 12 on the front wall portion 1802 and the rear wall portion 1804 of the seat cross member 18 .

[0014] Next, the effects of the vehicle when the vehicle is hit on the side of a pole or a barrier will be described as examples. First, a side collision with a pole will be described. During a side collision with a pole, the direction of the collision load applied to the seat cross member 18 from the pole P extending in the vertical direction is substantially the same as the extension direction of the seat cross member 18, as shown in FIG. 5(B). Therefore, when a collision load is input from pole P to the seat cross member 18 and floor panel 12, the central portion of the seat cross member 18 in the extension direction and the central portion of the floor panel 12 in the vehicle width direction tend to deform by bending upward and becoming convex upward. When the seat cross member 18 and floor panel 12 shown in Figure 3(A) attempt to fold upward, at the center of the extension direction of the seat cross member 18 and the center of the vehicle width direction of the floor panel 12, the upper wall portion 1806 of the seat cross member 18 and the floor panel 12 approach each other in the vertical direction, as shown in Figure 3(B), causing the seat cross member 18 to bend at the front wall portion 1802 and the rear wall portion 1804; in other words, the seat cross member 18 is deformed as if it is being crushed from above. As a result, the upper ends of the pair of side wall portions 2004 of the reinforcing member 20 abut against the lower surface of the upper wall portion 1806 of the seat cross member 18. When the upper ends of the pair of side wall portions 2004 abut against the lower surface of the upper wall portion 1806 of the seat cross member 18, further deformation of the seat cross member 18 in the upward bending direction is suppressed. Therefore, the strength of the seat cross member 18 can be ensured in the event of a side collision, which is advantageous in suppressing deformation of the vehicle body.

[0015] In this embodiment, as shown in Figure 2, a floor tunnel 22 is formed in the center of the floor panel 12 in the vehicle width direction, so the vertical width of the center of the extension direction of the seat cross member 18 is narrower than the vertical width of the area other than the center. Therefore, stress is more likely to concentrate in the center of the seat cross member 18 than in other areas, making it more likely to bend upward in a side collision. However, by providing the reinforcing member 20, the strength of the seat cross member 18 can be ensured in a side collision, which is advantageous in suppressing deformation of the vehicle body.

[0016] Next, a side collision with a barrier will be described as an example. In the event of a side collision with the barrier, as shown in Figure 5(C), the barrier B collides with a part of the vehicle body above the seat cross member 18, so the direction of the collision load applied from the barrier B to the seat cross member 18 and floor panel 12 is from above to diagonally downward relative to the extension direction of the seat cross member 18. Therefore, when a collision load is input from barrier B diagonally downward from above in the extension direction of seat cross member 18, the area near the end of seat cross member 18 on the impacted side and the area of ​​floor panel 12 on the impacted side will tend to deform downward, becoming convex downward. When the seat cross member 18 and floor panel 12 shown in Figure 4(A) attempt to deform so as to fold downward, as shown in Figure 4(B), the front wall portion 1802 and rear wall portion 1804 of the seat cross member 18 deform in a direction in which they approach each other (closing direction) at the points where they are joined to the floor panel 12 in response to the deformation of the floor panel 12, while the pair of side wall portions 2004 of the reinforcing member 20 deform in a direction in which their upper ends move away from each other (opening direction) in response to the deformation of the floor panel 12. As a result, as shown in FIG. 4(B), the corners of the first beads 26 of the floor panel 12 are locked onto the second beads 28 of the pair of side wall portions 2004 of the reinforcing member 20. When the corners of the first bead 26 of the floor panel 12 are engaged with the second beads 28 of the pair of side wall portions 2004, further deformation of the seat cross member 18 in the downward bending direction is suppressed. Therefore, the strength of the seat cross member 18 can be ensured in the event of a side collision, which is advantageous in suppressing deformation of the vehicle body.

[0017] In this embodiment, as shown in Figure 2, a pair of sudden vertical width changing portions 24D are provided near both ends of the seat cross member 18 in the extension direction, where the vertical width of the seat cross member 18 suddenly changes.The sudden vertical width changing portions 24D of the seat cross member 18 are more prone to stress concentration than areas other than the sudden vertical width changing portions 24D, and are therefore more likely to bend downward in a side collision.However, by providing a first bead 26 and a second bead 28 at a location spanning the sudden vertical width changing portions 24D, which are located more inward in the vehicle width direction than the side member 16, the strength of the seat cross member 18 can be ensured in the event of a side collision, which is advantageous in suppressing deformation of the vehicle body.

[0018] The shape and structure of the first bead 26 are not limited to those of the embodiment, and various conventionally known shapes and structures can be applied, and are not limited to those of the embodiment. Furthermore, the shape and structure of the second bead 28 are not limited to the embodiments, and various conventionally known shapes and structures can be applied, such as being configured with convex portions that protrude toward the front wall portion 1802 and the rear wall portion 1804, and are not limited to the embodiments. In addition, in this embodiment, the seat cross member 18 to which the present invention is applied has been described as a seat cross member 18, but the present invention is widely applicable to seat cross members 18 that are joined to the upper surface of the floor panel 12. However, in the case of this embodiment, deformation of the seat cross member 18 is suppressed in the event of a side collision in which the collision load is input near the seat cross member 18, and the strength of the seat cross member 18 is strengthened, which is advantageous in suppressing deformation of the vehicle body.

[0019] 10 vehicles 12 Floor Panel 14 Side sill 16 Side member 18 Seat cross member 1802 Front wall 1804 Rear wall 1806 Upper wall 1810 flange 1820 Sudden change in vertical width 20 Reinforcement member 2002 Bottom wall 2004 Pair of side walls 22-Floor Tunnel 24 Floor 24A Upper wall 24B Intermediate wall section 24C Lower wall part 26 First bead 28 Second bead P pole B Barrier F Collision load

Claims

1. A vehicle body structure in which a cross member is provided on an upper surface of a floor panel, the cross member having a front wall portion and a rear wall portion opposed to each other in the vehicle longitudinal direction, and an upper wall portion connecting upper ends of the front wall portion and the rear wall portion, and extending in a vehicle width direction, A reinforcing member is provided inside the cross member and extends along the extension direction of the cross member, the reinforcing member includes a bottom wall portion attached to the floor panel and a pair of side wall portions rising from front and rear ends of the bottom wall portion in the vehicle longitudinal direction and extending to the vicinity of the upper wall portion of the cross member, a first bead facing the side wall portion is provided at a location of the front wall portion and the rear wall portion of the cross member near the floor panel, or at a location of the floor panel near the front wall portion and the rear wall portion, A second bead is provided on the pair of side wall portions. A vehicle body structure characterized by:

2. The cross member has a pair of vertical width changing portions where the vertical width changes suddenly at locations near both ends in the extension direction of the cross member, The reinforcing member extends across the pair of vertical width-changing portions, The first bead and the second bead are provided at locations where the reinforcing member straddles each of the vertical width change portions.

2. The vehicle body structure according to claim 1.

3. A pair of side members extending in the front-rear direction of the vehicle are provided, the pair of vertical width-changing portions are formed on the inner side of the side members in the vehicle width direction; 3. The vehicle body structure according to claim 2.

4. The cross member is a seat cross member.

2. The vehicle body structure according to claim 1.

Images