Vehicle underbody structure

Abstract

To provide a lower vehicle body structure which can secure good lateral collision performance regardless of a contact height of a collision body during a lateral collision.SOLUTION: A lower vehicle body structure includes: a cross member 6 installed on an upper surface of a floor panel 4 and extending in a vehicle width direction; and a side sill 8 connected with the outer end side as seen in the vehicle width direction of the floor panel 4 and extending in an anteroposterior direction. The cross member 6 and the side sill 8 are spaced apart in the vehicle width direction, and a gusset 10 disposed between the cross member 6 and the side sill 8 is provided. The gusset 10 has: a protruding part 13 connected to an upper part of the side sill 8; and a pair of front and rear flanges 14 each connected with a side part of the side sill 8 and the outer end side as seen in the vehicle width direction of the cross member 6.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an underbody structure for a vehicle that includes a cross member installed on an upper surface of a floor panel and a side sill connected to an end of the floor panel in the vehicle width direction. [Background technology]

[0002] A typical lower body structure of a vehicle includes a floor panel forming the floor of the vehicle body, a cross member installed on the upper surface of the floor panel and extending in the vehicle width direction, and a side sill connected to an end of the floor panel in the vehicle width direction and extending in the front-rear direction (see, for example, Patent Document 1). In the lower body structure described in Patent Document 1, the cross member is connected to the side sill via a seat mounting bracket located on the outer side in the vehicle width direction. The seat mounting bracket has a flange that extends upward from its outer edge in the vehicle width direction, and the flange is joined to a side portion of the side sill. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-14353 A Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, when a collision object strikes the side of a vehicle, if the collision object is a utility pole or the like, it comes into direct contact with the side sill of the vehicle body, and resistance is generated by the side sill, cross member, etc. On the other hand, if the collision object is a vehicle or the like, the collision object comes into contact with a position higher than the side sill of the vehicle body at the beginning of the collision. In this case, in the lower body structure described in Patent Document 1, the seat mounting bracket is joined to the side portion of the side sill, so that the upper part of the side sill cannot be supported properly. As a result, at the beginning of the collision, the side sill moves relatively far toward the inside of the vehicle, and the intrusion amount of the collision object cannot be sufficiently suppressed.

[0005] The present invention has been made in consideration of the above-mentioned circumstances, and its object is to provide a lower body structure that can ensure good side collision performance regardless of the contact height of the impact body during a side collision. [Means for solving the problem]

[0006] According to the present invention, there is provided a lower body structure for a vehicle comprising a cross member installed on the upper surface of a floor panel and extending in the vehicle width direction, and a side sill connected to the vehicle width outer end side of the floor panel and extending in the fore-and-aft direction, wherein the cross member and the side sill are spaced apart in the vehicle width direction and a gusset is provided between the cross member and the side sill, the gusset having a pair of front and rear side walls whose lower ends are connected to the vehicle width outer end side of the cross member, an upper wall connecting the upper ends of each side wall, a protrusion formed at the vehicle width outer end of the upper wall, protruding outward in the vehicle width direction from the upper wall and connected to an upper portion of the side sill, and a pair of front and rear flanges formed from a predetermined vertical position of the vehicle width outer end of each side wall to a predetermined vehicle width position of the lower end, extending outward in the fore-and-aft direction from each side wall, and connected to the side portions of the side sill and the vehicle width outer end side of the cross member.

[0007] According to this vehicle lower body structure, the cross member and the side sill are connected via a gusset, the upper part of the side sill is connected to a protruding part of the gusset, and the side part of the side sill is connected to a flange of the gusset. As a result, when an impact body such as another vehicle collides with the side of the vehicle and contacts the side sill of the vehicle body at a position higher than the side sill, the upper part of the side sill can be supported by the gusset, and the movement of the side sill toward the inside of the vehicle can be suppressed. On the other hand, when an impact body such as a utility pole collides with the side of the vehicle and contacts the side sill of the vehicle body, the gusset is crushed in the vehicle width direction, so that the necessary resistance can be generated.

[0008] In addition, in the above-mentioned vehicle lower body structure, the gusset may have a blocking wall that blocks a virtual opening formed by the vehicle width direction inner ends of each side wall and the upper wall and an upper portion of the cross member.

[0009] According to this lower body structure of the vehicle, the virtual openings formed by each side wall and upper wall of the gusset and the upper part of the cross member are blocked, thereby suppressing deformation of the gusset in the side cross section and increasing the rigidity and strength of the gusset.

[0010] In addition, the lower body structure of the above-mentioned vehicle may be provided with a frame that forms a closed cross-section together with the floor panel and extends approximately in the fore-and-aft direction, and the blocking wall of the gusset may be positioned in a position that overlaps with the vehicle widthwise outer end side of the frame when viewed in a plane.

[0011] According to this vehicle lower body structure, in the event of a side collision of the vehicle, the frame is formed relatively strongly and is therefore less likely to be crushed than other parts, whereas the parts of the vehicle body that are more likely to be crushed in the vehicle width direction than the frame are. Therefore, by arranging the blocking wall located at the inner end of the gusset in the vehicle width direction so as to overlap with the outer end of the frame in the vehicle width direction, the entire gusset is located in an area that is more likely to be crushed in the event of a side collision, and energy absorption by the gusset can be efficiently performed.

[0012] In the above vehicle lower body structure, the gusset may have a seat attachment portion formed on the upper wall.

[0013] According to this vehicle underbody structure, the gusset can be used for mounting the seat.

[0014] In the above vehicle lower body structure, the gusset is formed on at least one of the side walls, and the seat mounting portion is provided between the connecting portion of the protruding portion and the side sill in the vehicle width direction and the connecting portion of the seat mounting portion. of The support may have a bead disposed therebetween and extending in the vertical direction.

[0015] According to this vehicle lower body structure, the gusset can be crushed starting from the bead during a side collision of the vehicle, thereby making it possible to accurately set the deformation mode and resistance of the gusset during a side collision. Effect of the Invention

[0016] According to the vehicle lower body structure of the present invention, good side collision performance can be ensured regardless of the contact height of a colliding body during a side collision. [Brief description of the drawings]

[0017] [Figure 1] 1 is a side view of a vehicle showing an embodiment of the present invention. [Diagram 2] FIG. 2 is a perspective view of a lower body structure of a vehicle. [Diagram 3] FIG. 2 is an explanatory plan view of the lower body structure with the gusset removed. [Figure 4] FIG. 4 is an explanatory plan view of the lower body structure with the seat rails removed. [Diagram 5] FIG. 2 is a perspective view of the lower body structure with the seat rail removed. [Figure 6] FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Figures 1 to 6 show one embodiment of the present invention, where Figure 1 is a side view of a vehicle showing one embodiment of the present invention, Figure 2 is an explanatory oblique view of the lower body structure of a vehicle, Figure 3 is an explanatory plan view of the lower body structure with the gusset removed, Figure 4 is an explanatory plan view of the lower body structure with the seat rail removed, Figure 5 is an explanatory oblique view of the lower body structure with the seat rail removed, and Figure 6 is an explanatory front cross-sectional view of the lower body structure.

[0019] As shown in Fig. 1, a seat 2 is arranged in a vehicle interior space of a vehicle 1. The seat 2 is fixed to seat rails 3 (see Fig. 2) and is guided in the front-rear direction by the seat rails 3.

[0020] As shown in FIG. 2, the body structure of the vehicle 1 includes a floor panel 4 forming the floor of the vehicle body, a plurality of cross members 5, 6 installed on the upper surface of the floor panel 4 and extending in the vehicle width direction, a frame 7 (see FIG. 6) installed on the lower surface of the floor panel 4 and extending in the approximately front-rear direction, and a side sill 8 connected to the vehicle width direction end of the floor panel 4 and extending in the front-rear direction. In this embodiment, the frame 7 extends rearward and inclined outward in the vehicle width direction. In this embodiment, two cross members, a first cross member 5 and a second cross member 6, are provided at a distance in the front and rear. The floor panel 4 is formed to be convex upward toward the center in the vehicle width direction and has a tunnel 4a extending in the front-rear direction. The inner ends of the cross members 5, 6 in the vehicle width direction are connected to a tunnel 41. In this embodiment, the floor panel 4, the cross members 5, 6, the frame 7, and the side sill 8 are made of steel plates.

[0021] The first cross member 5 and the second cross member 6 are formed in a generally hat-shaped shape convex upward in a side cross section, and form a closed cross section together with the floor panel 4. In this embodiment, the outer end of the first cross member 5 in the vehicle width direction is connected to the side sill 8, while the second cross member 6 is separated from the side sill 8 in the vehicle width direction and is not connected to the side sill 8 as shown in FIG. 3. As shown in FIG. 4, in the body structure of this vehicle 1, a gusset 10 is provided between the second cross member 6 and the side sill 8. As shown in FIG. 5, the upper end of the gusset 10 is formed higher than the second cross member 6, and as shown in FIG. 2, the rear end side of the seat rail 3 on the outer side in the vehicle width direction is attached to the gusset 10. The rear end side of the seat rail 3 on the inner side in the vehicle width direction is attached to a bracket 20 provided on the inner side of the second cross member 6 in the vehicle width direction.

[0022] As shown in FIG. 5, the gusset 10 has a pair of front and rear side walls 11 whose lower ends are connected to the outer end side of the second cross member 6 in the vehicle width direction, an upper wall 12 connecting the upper ends of the side walls 11, a protrusion 13 formed at the outer end of the upper wall 12 in the vehicle width direction and connected to the side sill 8, and a pair of front and rear flanges 14 formed from a predetermined position in the vertical direction of the outer end of the vehicle width direction of each side wall 11 to a predetermined position in the vehicle width direction of the lower end and connected to the side sill 8 and the second cross member 6. The second cross member 6 has a pair of front and rear side walls 6a, an upper wall 6b connecting the side walls 6a, and a pair of front and rear flanges 6c extending outward in the front and rear direction from the lower end of each side wall 6a. The lower end of each side wall 11 of the gusset 10 is connected to each side wall 6a of the second cross member 6, and extends upward from a connection portion with each side wall 6a of the second cross member 6. The upper wall 12 of the gusset 10 is disposed at a position higher than the upper wall 6b of the second cross member 6. A seat mounting portion 12a for the seat rail 3 is formed on the upper wall 12 of the gusset 10, and the gusset 10 is used for mounting the seat 2. In this embodiment, the seat mounting portion 12a is formed near the inner end of the upper wall 12 in the vehicle width direction.

[0023] The gusset 10 also has a blocking wall 15 that blocks a virtual opening formed by the inner ends of the side walls 11 and the upper wall 12 in the vehicle width direction and the upper wall 6b of the cross member 6. This suppresses deformation of the gusset 10 in the side cross section, and increases the rigidity and strength of the gusset 10. The blocking wall 15 has a flange 15a at its lower end that extends inward in the vehicle width direction and is joined to the upper wall 6b of the second cross member 6. As shown in FIG. 6, the blocking wall 15 is disposed at a position that overlaps with the outer end side of the frame 7 in the vehicle width direction in a plan view. The frame 7 has a pair of left and right side walls 7a, a lower wall 7b that connects the side walls 7a, and a pair of front and rear flanges 7c that extend outward in the left and right direction from the lower ends of the side walls 7a. In this embodiment, the blocking wall 15 is disposed so as to overlap with the flange 7c on the outer side of the frame 7 in the vehicle width direction in a plan view.

[0024] Further, a bead 6d is formed on the front-rear center side of the upper wall 6b of the second cross member 6, extending in the extension direction of the frame 7 in correspondence with the side wall 7a on the inner side in the vehicle width direction of the frame 7. The outer end of the bead 6d in the vehicle width direction is disposed so as to overlap with the flange 7c on the inner side in the vehicle width direction of the frame 7 in a plan view. In this embodiment, the bead 6d is formed on the upper wall 6b of the second cross member 6 so as to be recessed downward.

[0025] In this embodiment, a reinforcing member 61 is provided in a closed cross section formed by the second cross member 6 and the floor panel 4. The reinforcing member 61 has a pair of front and rear side walls 61a and an upper wall 61b connecting the side walls 61a, and each side wall 61a of the reinforcing member 61 is joined to each side wall 6a of the second cross member 6, and the upper wall 61b of the reinforcing member 61 is joined to the upper wall 6b of the second cross member 6. The reinforcing member 61 has a vehicle width direction inner end 61c of the upper wall 61b formed to correspond to the vehicle width direction inner side wall 7a of the frame 7, and a vehicle width direction outer end 61d of the upper wall 61b formed to correspond to each bead 16 of the gusset 10 described later. The vehicle width direction inner end 61c of the upper wall 61b extends in the extension direction of the frame 7, and the vehicle width direction outer end 61d of the upper wall 61b extends in the front-rear direction. An inner end 61c of the upper wall 61b in the vehicle width direction is disposed so as to overlap with an inner flange 7c of the frame 7 in the vehicle width direction in a plan view. Further, an inner end 61d of the upper wall 61b in the vehicle width direction is disposed outside the outer flange 7c of the frame 7 in the vehicle width direction.

[0026] The protruding portion 13 of the gusset 10 protrudes from the upper wall 12 to the outside in the vehicle width direction and is joined to the upper portion of the side sill 8. The side sill 8 has an inner wall 8a on the inside in the vehicle width direction, an outer wall (not shown) on the outside in the vehicle width direction, an upper wall 8b connecting the upper ends of the inner wall 8a and the outer wall, and a lower wall (not shown) connecting the lower ends of the inner wall 8a and the outer wall. In this embodiment, the protruding portion 13 is joined to the upper wall 8b of the side sill 8. In addition, the upper wall 12 of the gusset 10 is disposed at a position lower than the upper wall 8b of the side sill 8. In this embodiment, the protruding portion 13 has an upward extending portion 13a extending upward from the outer end of the upper wall 12 in the vehicle width direction at an incline toward the outside in the vehicle width direction, and a joining portion 13b extending from the upper end of the upward extending portion 13a to the outside in the vehicle width direction and joined to the upper wall 8a of the side sill 8.

[0027] Each flange 14 of the gusset 10 extends outward in the front-rear direction from each side wall 11, and is joined to the inner wall 8a of the side sill 8 and each flange 6c of the second cross member 6. Each flange 14 has, from the outer end side in the vehicle width direction, a side sill joint portion 14a, an intermediate portion 14b, and a cross member joint portion 14c, in this order. The side sill joint portion 14a is formed along the inner wall 8a of the side sill 8, and is joined to the inner wall 8a by spot welding.

[0028] As shown in FIG. 5, the outer end side of each flange 6c of the second cross member 6 in the vehicle width direction is separated from the floor panel 4. Specifically, the outer end side of each flange 6c of the second cross member 6 in the vehicle width direction extends in a curved upward direction so as to be convex obliquely downward toward the outside in the vehicle width direction when viewed from the front. The cross member joint portion 14c of each flange 14 of the gusset 10 is formed along each flange 6c of the second cross member 6 and is joined to each flange 6c of the second cross member 6 by spot welding. The middle portion 14b of each flange 14 of the gusset 10 is formed continuously with the side sill joint portion 14a and the cross member joint portion 14c, and smoothly connects them. In this embodiment, each flange 14 of the gusset 10 is formed in a curved shape and is formed from the uppermost part of the outer end of each side wall 11 in the vehicle width direction to a position corresponding to the position of each flange 6c of the second cross member 6 separated from the floor panel 4 at the lower end of each side wall 11.

[0029] The gusset 10 also has beads 16 formed on each side wall 11 and extending in the up-down direction. Each bead 16 is disposed in the vehicle width direction between a joint 13a of the protruding portion 13 with the side sill 8 and a seat attachment portion 12a of the upper wall 12. In this embodiment, the beads 16 are disposed in pairs, front and rear, on the vehicle width outer sides of the vehicle width outer ends 61d of the reinforcing members 61.

[0030] According to the vehicle body structure configured as described above, when an impact body such as another vehicle collides with the side of the vehicle and contacts the vehicle body at a position higher than the side sill, the upper part of the side sill 8 can be supported by the gusset 10, and movement of the side sill 8 toward the inside of the vehicle can be suppressed.

[0031] On the other hand, when a collision object such as a utility pole collides with the side of the vehicle and comes into contact with the side sill 8 of the vehicle body, the gusset 10 is crushed in the vehicle width direction, thereby generating the necessary resistance. In this embodiment, the gusset 10 can be crushed starting from each bead 16. This makes it possible to accurately set the deformation mode and resistance of the gusset 10 during a side collision.

[0032] At this time, since the frame 7 is formed relatively strongly, it is less likely to be crushed than other parts, and the part of the vehicle body that is more likely to be crushed on the outer side of the frame 7 in the vehicle width direction is more likely to be crushed. Therefore, by arranging the blocking wall 15 located at the inner end of the gusset 10 in the vehicle width direction so as to overlap with the outer end side of the frame 7 in the vehicle width direction, the entire gusset 10 is located in an area that is easily crushed during a side collision, and energy absorption by the gusset 10 can be performed efficiently. In addition, the second cross member 6 is folded at the position of the inner end 6c in the vehicle width direction of the reinforcing member 61, and the second cross member 6 can be folded while avoiding the frame 7 that is difficult to deform. In this embodiment, the bead 6d of the upper wall 6b of the second cross member 6 is also formed corresponding to the side wall 7a on the inner side in the vehicle width direction of the frame 7, and the folding mode of the second cross member 6 can be accurately controlled. As a result, energy absorption by the second cross member 6 can be performed efficiently during a side collision.

[0033] In the above embodiment, the seat rail 3 is fixed to the gusset 10, but the gusset 10 may be provided independently of the seat 2. In addition, the blocking wall 15 of the gusset 10 overlaps with the outer end side of the frame 7 in the vehicle width direction, but the position of the blocking wall 15 in the vehicle width direction can be changed arbitrarily, and further, a configuration in which the blocking wall 15 is not provided may be used.

[0034] In the above embodiment, each flange 6c of the second cross member 6 is separated from the floor panel 4 at its outer end in the vehicle width direction, but the shape of the second cross member 6 is arbitrary, and the outer end in the vehicle width direction does not necessarily have to be separated. Whatever the shape of the second cross member 6, it is sufficient that each flange 14 of the gusset 10 is connected to the second cross member 6 and the side sill 8.

[0035] In the above embodiment, the joint portion 13b of the protruding portion 13 of the gusset 10 joined to the side sill 8 is formed via the upward extending portion 13a, but it is not necessarily required to be formed via the upward extending portion 13a. The protruding portion 13 only needs to be connected to the upper portion of the side sill 8, and the shape, etc. can be appropriately changed depending on the relative heights, etc. of the upper wall 12 of the gusset 10 and the upper portion of the side sill 8.

[0036] In the above embodiment, the bead 16 is formed on each of the side walls 11 of the gusset 10, but the bead 16 may be formed on only one of the side walls 11. Also, a plurality of beads 16 may be formed on each side wall at intervals in the vehicle width direction, or the bead 16 may be omitted.

[0037] Although the embodiments of the present invention have been described above, the invention according to the claims is not limited to the embodiments described above. It should be noted that not all of the combinations of features described in the embodiments are essential to the means for solving the problems of the invention. [Explanation of symbols]

[0038] 4 Floor Panel 6 Second cross member 7 Frame 8 Side sill 10 Gusset 11 Side wall 12 Upper wall 12a Seat mounting part 13 Protrusion 14 Flange 15 Blocking wall 16 Beads

Claims

1. A cross member installed on an upper surface of the floor panel and extending in a vehicle width direction; a side sill connected to an outer end side of the floor panel in a vehicle width direction and extending in a front-rear direction, The cross member and the side sill are spaced apart in the vehicle width direction, A gusset is provided between the cross member and the side sill, The cross member has a pair of front and rear side walls and an upper wall connecting the side walls, The gusset is A pair of front and rear side walls each having a lower end connected to a vehicle width direction outer end side of the side wall of the cross member and extending upward from a connection portion between the cross member and the side wall; an upper wall connecting upper ends of the side walls of the gusset and positioned higher than the upper wall of the cross member; a protrusion formed at an outer end of the upper wall of the gusset in the vehicle width direction, protruding outward in the vehicle width direction from the upper wall of the gusset and connected to an upper portion of the side sill; a pair of front and rear flanges each formed from a predetermined position in the up-down direction of a vehicle width direction outer end of each side wall of the gusset to a predetermined position in the vehicle width direction of a lower end, extending outward in the front-rear direction from each side wall of the gusset, and connected to a side portion of the side sill and a vehicle width direction outer end side of the cross member; The gusset has a blocking wall that blocks a virtual opening formed by inner ends of the side walls and the upper wall of the gusset in the vehicle width direction and the upper wall of the cross member, A frame is provided that forms a closed cross section together with the floor panel and extends in a substantially front-rear direction, A vehicle underbody structure, wherein the closing wall of the gusset is positioned so as to overlap with the outer end side of the frame in the vehicle width direction in a plan view.

2. 2. The vehicle underbody structure of claim 1, wherein the gusset has a seat attachment portion formed in the top wall of the gusset.

3. 3. The vehicle underbody structure according to claim 2, wherein the gusset has a bead formed on at least one of the side walls of the gusset, is disposed between the connection portion of the protrusion with the side sill and the seat mounting portion in the vehicle width direction, and extends in the vertical direction.

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