JP6264864B2 - Vehicle lower structure - Google Patents

Description

  The present invention relates to a vehicle lower structure.

  In a vehicle lower structure including a pair of rockers extending in the vehicle front-rear direction and a floor cross member extending between the rockers in the vehicle width direction, Patent Document 1 discloses a cross member (floor cross member). A vehicle lower structure is disclosed in which a side sill (rocker) is connected by a box-shaped four-sided connecting member (connecting member). Here, the coupling member includes an upper surface portion that extends inward in the vehicle width direction from the side surface of the side sill, and front and rear both surface portions that extend downward from the front end portion and rear end portion of the upper surface portion and are joined to the cross member. And an inner surface portion that extends downward from the inner end of the upper surface portion in the vehicle width direction and is connected to the cross member.

JP 2012-66804 A

  By the way, the connecting member that connects the floor cross member and the rocker is located in a foot space of an occupant seated on the rear seat. For this reason, in order to secure this toe space, it is necessary to configure so that the connecting member does not protrude inward in the vehicle width direction. The surface (inner surface portion) is formed at an angle close to perpendicular to the cross member. On the other hand, considering the collision load at the time of a side collision of the vehicle (hereinafter referred to as “vehicle side collision”), a part of the collision load input to the rocker at the side collision is the inner surface portion of the coupling member from the rocker. Therefore, the load in the vertical direction is concentrated from the inner surface to the floor cross member. For this reason, the floor cross member may be bent or damaged, and the transmission of the collision load may be hindered, and there is room for improvement from the viewpoint of effectively transmitting the collision load at the time of a side collision to the cross member.

  In view of the above fact, an object of the present invention is to provide a vehicle lower structure capable of effectively transmitting a collision load at the time of a side collision to a floor cross member.

According to a first aspect of the present invention, there is provided a vehicle lower structure, which is provided at both ends in the vehicle width direction of the lower portion of the vehicle and extends in the vehicle front-rear direction, and between the pair of rockers in the vehicle width direction. The floor cross member that is extended and has one end joined to the lower portion of the rocker, and the side surface of the rocker in the vehicle width direction and the upper portion of the floor cross member are connected, and at least from the rocker to the vehicle width direction. A connecting member comprising: a lateral wall portion extending inward; and a vertical wall portion extending downward from the lateral wall portion and joined to the floor cross member; and the connecting member and the floor cross member It is arrange | positioned between upper part, it is extended diagonally downward toward the upper part of the said floor cross member from the junction part of the said rocker and the said horizontal wall part, and it joins the said vertical wall part and the said floor cross member And has a diagonal members having a lower end joined to the upper portion of the floor cross member in the vehicle width direction substantially the same position, wherein the diagonal member has an outer flange portion arranged outside in the vehicle width direction, the vehicle width direction An inner flange portion disposed on the inner side, and the outer flange portion is a rocker inner panel vehicle disposed on the inner side in the vehicle width direction of the rocker from the outer end portion of the connecting member in the vehicle width direction. An outer flange portion of the connecting member bent along an inner side vertical wall portion extending in the vertical direction is formed in substantially the same shape, and the outer flange portion of the connecting member and the inner side vertical wall portion The inner flange portion is joined to the inner side of the connecting member that is bent inward in the vehicle width direction along the upper surface of the floor cross member from the lower end portion of the vertical wall portion of the connecting member. Franc Are joined in a state of being sandwiched between the parts and between the inner flange portion of substantially the connecting member identical shape are formed to the floor cross member.

  According to the vehicle lower structure according to the first aspect of the present invention, the floor cross member extends in the vehicle width direction between the pair of rockers, and one end of the floor cross member is joined to the lower portion of the rocker. Has been. Further, the side surface of the rocker in the vehicle width direction and the upper portion of the floor cross member are connected by a connecting member. The connecting member includes at least a horizontal wall portion extending inward in the vehicle width direction from the rocker, And a vertical wall portion that extends downward from the vehicle and is joined to the floor cross member. For this reason, a part of the collision load input at the time of a side collision of the vehicle is transmitted from the rocker to the floor cross member via the horizontal wall portion and the vertical wall portion of the connecting member.

Here, the diagonal material extends obliquely downward from the joint portion between the rocker and the horizontal wall portion to the upper portion of the floor cross member between the connecting member and the upper portion of the floor cross member , and the vertical wall portion and the floor The lower end portion of the diagonal member is joined to the upper portion of the floor cross member at substantially the same position as the joint portion with the cross member in the vehicle width direction . Thereby, a part of the collision load input to the connecting member is dispersed in the diagonal member, and the vertical load acting on the floor cross member from the vertical wall portion can be reduced. As a result, the floor cross member can be prevented from being broken or damaged, and the collision load at the time of a side collision can be effectively transmitted to the floor cross member.

Further , according to the vehicle lower structure according to the first aspect of the present invention, the downward load applied from the vertical wall portion and the diagonal material are applied to the joint portion between the vertical wall portion and the floor cross member. A load obtained by combining the load in the diagonally downward direction is applied. Thereby, it is possible to suppress the floor cross member from being broken or damaged by the load applied from the vertical wall portion.

A vehicle lower structure according to a second aspect of the present invention is the vehicle lower structure according to the first aspect , wherein the connecting member is a seat mounting bracket that supports a vehicle seat.

A vehicle lower structure according to a third aspect of the present invention is the vehicle lower structure according to the second aspect , wherein the seat mounting bracket extends downward from both ends of the lateral wall portion in the vehicle front-rear direction. And a side wall portion joined to the floor cross member. Both ends of the diagonal member in the vehicle front-rear direction are joined to the side wall portion.

According to the vehicle lower structure according to the third aspect of the present invention, the rigidity of the seat mounting bracket is increased by joining both end portions of the diagonal member in the vehicle longitudinal direction to the side wall portion of the seat mounting bracket. The seat mounting bracket can be prevented from collapsing in cross section due to the vehicle vertical load applied from the seat and the occupant.

A vehicle lower structure according to a fourth aspect of the present invention is the vehicle lower structure according to any one of the first to third aspects, wherein a reinforcing member is provided inside the rocker. And the said reinforcement member is joined to the said rocker in the position which overlaps when the junction part of the said rocker and the said side wall part is projected on the vehicle width direction.

According to the vehicle lower structure according to the fourth aspect of the present invention, the collision load input to the rocker can be transmitted to the connecting member and the diagonal member via the reinforcing member.

Vehicle underbody structure according to the present invention described in claim 5 is the vehicle underbody structure according to claim 4, wherein the rocker includes includes a rocker outer panel that is disposed on the rocker inner panel and the vehicle width direction outer side The reinforcing member is connected to the rocker inner panel and the rocker outer panel.

According to the vehicle lower structure according to the fifth aspect of the present invention, compared to the case where the vehicle lower structure is joined to only one of the rocker inner panel and the rocker outer panel, the floor crossing is more effectively applied to the collision load input to the rocker. Can be communicated to members.

  As described above, the vehicle lower structure according to the present invention has an excellent effect that the collision load at the time of a side collision can be effectively transmitted to the floor cross member.

1 is a schematic perspective view showing a vehicle lower part structure according to an embodiment of the present invention as viewed from the vehicle front side. It is the perspective view seen from the vehicle front side which shows the junction part of the rocker and floor cross member which comprise the vehicle lower part structure which concerns on embodiment of this invention. FIG. 3 is a perspective view seen from the vehicle front side, showing a state in which an outer seat mounting bracket is removed from the state of FIG. 2. It is the perspective view seen from the vehicle front side which shows the bulkhead in the rocker which comprises the vehicle lower part structure which concerns on embodiment of this invention. It is sectional drawing which cut | disconnected the junction part of the rocker and floor cross member which comprise the vehicle lower part structure which concerns on embodiment of this invention along the vehicle width direction. It is a 5-5 line sectional view showing the state where the collision load at the time of a side collision is transmitted. It is sectional drawing which cut | disconnected the bracket for outer sheet | seats which comprises the vehicle lower part structure which concerns on embodiment of this invention along the vehicle front-back direction.

  Hereinafter, a vehicle lower structure 10 according to an embodiment of the present invention will be described with reference to the drawings. In addition, an arrow FR appropriately shown in each drawing indicates the vehicle front side, an arrow UP indicates the vehicle upper side, and an arrow LH indicates the vehicle left side in the vehicle width direction. Further, in the following description, when using the front / rear, up / down, and left / right directions, the front / rear direction of the vehicle, the up / down direction of the vehicle up / down direction, and the left / right direction in the traveling direction are indicated.

(Overall structure of vehicle lower structure)
As shown in FIG. 1, the vehicle lower structure 10 of the present embodiment mainly includes a floor panel 12, a rocker 14, a first floor cross member 18, and a second floor cross member 16. The floor panel 12 is a substantially rectangular plate material in plan view that constitutes the bottom surface of the vehicle, and a tunnel portion 12A formed by bending the floor panel 12 upward is formed at the vehicle width direction central portion of the floor panel 12. Is provided. The tunnel portion 12A extends in the vehicle front-rear direction, and the front end portion of the tunnel portion 12A is joined to a dash panel (not shown). The rear end portion of the tunnel portion 12 </ b> A is joined to the rear cross member 20 extending in the vehicle width direction at the rear end portion of the floor panel 12.

  A pair of rockers 14 are provided at both ends of the floor panel 12 in the vehicle width direction. The rockers 14 are provided in parallel to each other and extend in the vehicle front-rear direction. Each rocker 14 has a closed cross section including a rocker inner panel 26 disposed on the inner side in the vehicle width direction and a rocker outer panel 28 disposed on the outer side in the vehicle width direction. Details of the rocker 14 will be described later.

  Here, a first floor cross member 18 and a second floor cross member 16 are provided between the pair of rockers 14. The first floor cross member 18 is formed in a substantially rectangular shape in plan view, and extends between the rockers 14 in the vehicle width direction.

  The first floor cross member 18 is provided as a pair on the left and right sides of the tunnel portion 12A, and the first floor cross member 18L on the left side of the vehicle is the rocker inner panel 26 of the rocker 14 on the left side of the vehicle and the left side of the tunnel portion 12A. It is provided between the surface 12B. On the other hand, the first floor cross member 18R on the right side of the vehicle is provided between the rocker inner panel 26 of the rocker 14 on the right side of the vehicle and the right side surface 12C of the tunnel portion 12A.

  Here, a lower flange portion 18A bent in the longitudinal direction of the vehicle is provided at the lower end portion of the first floor cross member 18, and the lower flange portion 18A and the floor panel 12 are joined by spot welding or the like. Yes. For this reason, the cross section which cut | disconnected the 1st floor cross member 18 along the vehicle front-back direction is made into hat shape.

  Further, an inner flange portion 18B that is bent in the vehicle upper direction and the vehicle front-rear direction along the left side surface 12B (right side surface 12C) of the tunnel portion 12A is provided at the inner end in the vehicle width direction of the first floor cross member 18. The inner flange portion 18B and the left side surface 12B (right side surface 12C) of the tunnel portion 12A are joined by spot welding or the like. Further, an outer flange portion 18C that is bent in the vehicle upper direction and the vehicle front-rear direction along the rocker inner panel 26 is provided at the outer end portion in the vehicle width direction, and the outer flange portion 18C, the rocker inner panel 26, and the like. Are joined by spot welding or the like.

  Bolt holes 18D are formed on the upper surfaces of both ends in the vehicle width direction of the first floor cross member 18, and a weld (not shown) is formed on the inner surface of the first floor cross member 18 at a position corresponding to the bolt holes 18D. A nut is provided. The seat rail for slidably supporting the vehicle seat can be fixed to the first floor cross member 18 by inserting a bolt into the bolt hole 18D.

  A pair of left and right second floor cross members 16 are provided substantially parallel to the first floor cross member 18 on the vehicle rear side from the first floor cross member 18. The second floor cross member 16 is a member having a substantially rectangular shape in plan view and formed lower in height than the first floor cross member 18, and extends between the rockers 14 in the vehicle width direction. The second floor cross member 16L on the left side of the vehicle is provided between the lower portion of the rocker inner panel 26 on the left side of the vehicle and the lower portion of the left side surface 12B of the tunnel portion 12A, and the second floor cross member 16R on the right side of the vehicle. Is provided between the lower part of the rocker inner panel 26 on the right side of the vehicle and the lower part of the right side surface 12C of the tunnel part 12A.

  Here, a lower flange portion 16A bent in the longitudinal direction of the vehicle is provided at the lower end portion of the second floor cross member 16, and the lower flange portion 16A and the floor panel 12 are joined by spot welding or the like. Yes. Thereby, as for the 2nd floor cross member 16, the cross section cut | disconnected along the vehicle front-back direction is made into hat shape. Further, an inner flange portion 16B that is bent in the vehicle upper direction and the vehicle front-rear direction along the left side surface 12B (right side surface 12C) of the tunnel portion 12A is provided at the inner end in the vehicle width direction of the second floor cross member 16. The inner flange portion 16B and the left side surface 12B (right side surface 12C) of the tunnel portion 12A are joined by spot welding or the like. Further, an outer flange portion 16C that is bent in the vehicle upper direction and the vehicle front-rear direction along the rocker inner panel 26 is provided at the outer end portion in the vehicle width direction, and the outer flange portion 16C, the rocker inner panel 26, Are joined by spot welding or the like.

  An inner seat mounting bracket 22 connected to the side surface of the tunnel portion 12A and the upper surface of the second floor cross member 16 is provided at the inner end in the vehicle width direction of the second floor cross member 16 (FIG. 1). Only the inner seat mounting bracket 22 on the left side of the vehicle is shown). The inner seat mounting bracket 22 is a tetrahedral member having an upper surface, a vehicle front side surface (front surface), a vehicle rear side surface (rear surface), and a vehicle width direction outer surface (outer surface). An outer flange portion 22A that is bent outward in the vehicle width direction along the upper surface of the second floor cross member 16 is provided at the lower end portion of the outer side surface. The outer flange portion 22A is superimposed on the upper surface of the second floor cross member 16 and joined by spot welding or the like.

  A front flange portion 22 </ b> B extends downward on the front surface of the inner seat mounting bracket 22. The front flange portion 22B is overlapped with the front surface of the second floor cross member 16 and is joined by spot welding or the like. A rear flange portion (not shown) is provided on the rear surface of the inner seat mounting bracket 22 in the same manner as the front surface, and is overlapped with the rear surface of the second floor cross member 16 and joined by spot welding or the like. Yes.

  Inner flange portions 22 </ b> C that are bent along the left side surface 12 </ b> B (right side surface 12 </ b> C) of the tunnel portion 12 </ b> A are provided at the vehicle width direction inner ends of the upper surface, front surface, and rear surface of the inner seat mounting bracket 22. Yes. The inner flange portion 22C is superimposed on the left side surface 12B (right side surface 12C) of the tunnel portion 12A and joined by spot welding or the like. A bolt hole 22D for fixing the seat rail is formed on the upper surface of the inner seat mounting bracket 22.

  An outer seat mounting bracket 24 as a connecting member is provided at the outer end of the second floor cross member 16 in the vehicle width direction. The outer seat mounting bracket 24 is a tetrahedral member formed in the same manner as the inner seat mounting bracket 22, and connects the upper part of the rocker inner panel 26 and the upper part of the second floor cross member 16. The detailed configuration of the outer seat mounting bracket 24 will be described later.

(Configuration of rocker and bracket for mounting outer seat)
Next, detailed configurations of the rocker 14 and the outer seat mounting bracket 24 will be described. In addition, since the vehicle left side and the vehicle right side have the same configuration with the tunnel portion 12A interposed therebetween, in the following description, only the configuration on the right side of the vehicle is illustrated and described, and the description on the configuration on the left side of the vehicle is omitted.

  First, the detailed configuration of the rocker 14 will be described. As shown in FIG. 2, the rocker outer panel 28 constituting the rocker 14 is mainly composed of an outer side vertical wall portion 28C, an outer side lower wall portion 28B, an outer side upper wall portion 28D, and an outer side lower flange portion 28A. And an outer-side upper flange portion 28E.

  The outer side vertical wall portion 28C extends in the vehicle vertical direction, and an outer side lower wall portion 28B that is bent inward in the vehicle width direction is provided at the lower end portion of the outer side vertical wall portion 28C. . The outer-side lower wall portion 28B is gently inclined downward from the outer-side vertical wall portion 28C toward the inner side in the vehicle width direction. A bent outer side lower flange portion 28A is provided.

  Further, an outer side upper wall portion 28D that is bent inward in the vehicle width direction is provided at the upper end portion of the outer side vertical wall portion 28C. The outer-side upper wall portion 28D is gently inclined upward from the outer-side vertical wall portion 28C inward in the vehicle width direction, and the outer-side upper wall portion 28D has an upward end at the inner end in the vehicle width direction. A bent outer side upper flange portion 28E is provided.

  On the other hand, the rocker inner panel 26 is a member having a hat-shaped cross section cut along the vehicle width direction, and is disposed such that the outer side in the vehicle width direction is opened. The rocker inner panel 26 mainly includes an inner side vertical wall portion 26C, an inner side lower wall portion 26B, an inner side upper wall portion 26D, an inner side lower flange portion 26A, and an inner side upper flange portion 26E. I have.

  The inner side vertical wall portion 26C extends in the vehicle vertical direction, and an inner side lower wall portion 26B bent outward in the vehicle width direction is provided at the lower end portion of the inner side vertical wall portion 26C. . The inner side lower wall portion 26B is gently inclined downward from the inner side vertical wall portion 26C toward the outer side in the vehicle width direction, and the inner side lower wall portion 26B has a lower end at the inner end in the vehicle width direction. A bent inner side lower flange portion 26A is provided. Here, the inner side lower flange portion 26A and the outer side lower flange portion 28A of the rocker outer panel 28 are joined by spot welding or the like. Further, the end portion 12D of the floor panel 12 is joined to the inner side lower wall portion 26B by spot welding or the like.

  An inner side upper wall portion 26D that is bent outward in the vehicle width direction is provided at the upper end portion of the inner side vertical wall portion 26C. The inner side upper wall portion 26D is gently inclined upward from the inner side vertical wall portion 26C toward the outer side in the vehicle width direction, and is further bent outward in the vehicle width direction at the upper end portion. Further, an inner side upper flange portion 26E that is bent upward is provided at the inner end in the vehicle width direction of the inner side upper wall portion 26D, and spot welding or the like is performed with the outer side upper flange portion 28E of the rocker outer panel 28. It is joined with.

  In the present embodiment, the outer side vertical wall portion 28C of the rocker outer panel 28 and the inner side vertical wall portion 26C of the rocker inner panel 26 are formed in a planar shape, but the present invention is not limited to this and is formed in other shapes. May be. For example, at least one of the outer-side vertical wall portion 28C and the inner-side vertical wall portion 26C may be bent in a concavo-convex shape so that the ridgeline extending in the vehicle front-rear direction increases. In this way, the rigidity of the rocker 14 against the load acting in the vehicle width direction can be increased.

  Here, as shown in FIG. 4, the rocker 14 includes a front bulkhead 32 and a rear bulkhead 34 as reinforcing members. The front bulkhead 32 and the rear bulkhead 34 are formed by bending a sheet metal, and are located inside a portion where the second floor cross member 16 and the outer seat mounting bracket 24 are provided. In other words, the front bulkhead 32 and the rear bulkhead 34 are joined to the rocker 14 at a position where they overlap when the joint between the rocker inner panel 26 and the bracket upper surface 24A is projected in the vehicle width direction.

  The front bulkhead 32 includes a front flat plate portion 32A formed in a shape corresponding to the shape of the inside of the rocker 14, and upper and lower end portions of the front flat plate portion 32A are bent forward of the vehicle. A flange portion 32C and a lower flange portion 32B are provided. Here, the upper flange portion 32C is joined to the outer side upper wall portion 28D of the rocker outer panel 28 and the inner side upper wall portion 26D of the rocker inner panel 26 by spot welding or the like, and connects the two. The lower flange portion 32B is joined to the outer side lower wall portion 28B and the inner side lower wall portion 26B by spot welding or the like, and connects the two.

  Further, an inner flange portion 32D that is bent forward of the vehicle is provided at an end of the front flat plate portion 32A on the inner side in the vehicle width direction. When the inner flange portion 32D is projected in the vehicle width direction, the inner flange portion 32D is positioned at a position where it overlaps with an outer flange portion 16C of the second floor cross member 16 and an outer flange portion 24H of an outer seat mounting bracket 24 described later. It is joined to the side vertical wall portion 26C by spot welding or the like.

  On the other hand, like the front bulkhead 32, the rear bulkhead 34 includes a rear flat plate portion 34A formed in a shape corresponding to the internal shape of the rocker 14, and an upper end portion of the rear flat plate portion 34A. Is provided with an upper flange portion 34C bent toward the rear of the vehicle. Further, a lower flange portion 34B bent toward the rear of the vehicle is provided at the lower end portion of the rear flat plate portion 34A (see FIG. 5). Here, the upper flange portion 34C is joined to the outer side upper wall portion 28D of the rocker outer panel 28 and the inner side upper wall portion 26D of the rocker inner panel 26 by spot welding or the like, and connects the two. The lower flange portion 34B is joined to the outer side lower wall portion 28B and the inner side lower wall portion 26B by spot welding or the like, and connects the two.

  Further, an inner flange portion 34D that is bent rearward of the vehicle is provided at the inner end in the vehicle width direction of the rear flat plate portion 34A. The inner flange portion 34D is joined to the inner side vertical wall portion 26C by spot welding or the like.

  In addition, a connecting plate 36 is provided between the end of the front bulkhead 32 on the outer side in the vehicle width direction and the end of the rear bulkhead 34 on the outer side in the vehicle width direction. The connecting plate 36 is formed integrally with the front bulkhead 32 and the rear bulkhead 34, and extends in the vehicle front-rear direction to connect the front bulkhead 32 and the rear bulkhead 34. Further, the connecting plate 36 is joined to the outer side vertical wall portion 28C of the rocker outer panel 28 by spot welding or the like.

  Next, a detailed configuration of the outer sheet mounting bracket 24 will be described. As shown in FIG. 2, the outer seat mounting bracket 24 includes a bracket upper surface 24A as a lateral wall portion, a bracket inner side surface 24B as a vertical wall portion, a bracket front surface 24C and a bracket rear surface 24D as side wall portions. It is formed in a tetrahedron shape. The bracket upper surface 24A is formed in a substantially rectangular shape in plan view, and extends from the inner side vertical wall portion 26C of the rocker inner panel 26 to the inner side in the vehicle width direction. Further, a bolt hole 24J for fixing the seat rail is formed on the bracket upper surface 24A, and a weld nut 40 is welded to a position corresponding to the bolt hole 24J on the back side of the bracket upper surface 24A (see FIG. 5).

  Further, the bracket inner side surface 24B extends downward from the end portion on the inner side in the vehicle width direction of the bracket upper surface 24A toward the upper surface of the second floor cross member 16. The bracket inner side surface 24B is formed in a substantially rectangular shape when viewed from the vehicle width direction. Here, an inner flange portion 24E that is bent inward in the vehicle width direction along the upper surface of the second floor cross member 16 is provided at the lower end portion of the bracket inner side surface 24B. The inner flange portion 24E is joined to the upper surface of the second floor cross member 16 by spot welding or the like with an inner flange portion 30B of the diagonal member 30 described later interposed therebetween.

  A bracket front surface 24C extends downward toward the second floor cross member 16 at the end of the bracket upper surface 24A on the vehicle front side. The bracket front surface 24C is formed in a substantially rectangular shape when viewed from the front side of the vehicle, and is formed integrally with the bracket upper surface 24A and the bracket inner surface 24B. In addition, a front flange portion 24F extends downward from the lower end portion of the bracket front surface 24C continuously to the bracket front surface 24C, and the front flange portion 24F has a lower end portion 30G of the diagonal member 30 to be described later. The two floor cross member 16 is joined to the front surface of the vehicle by spot welding or the like.

  As shown in FIG. 7, a bracket rear surface 24 </ b> D extends downward toward the second floor cross member 16 at an end of the bracket upper surface 24 </ b> A on the vehicle rear side. The bracket rear surface 24D is formed in a substantially rectangular shape when viewed from the vehicle rear side, and is formed integrally with the bracket upper surface 24A and the bracket inner surface 24B. In addition, a rear flange portion 24G extends downward from the lower end portion of the bracket rear surface 24D continuously to the bracket rear surface 24D, and the rear flange portion 24G is an oblique material to be described later in the same manner as the front flange portion 24F. The second floor cross member 16 is joined to the surface on the vehicle front side of the second floor cross member 16 by spot welding or the like.

  An outer flange portion 24H that is bent along the inner side vertical wall portion 26C of the rocker inner panel 26 is provided at the outer ends in the vehicle width direction of the bracket upper surface 24A, the bracket front surface 24C, and the bracket rear surface 24D. The outer flange portion 24H is formed in an inverted U shape along the outer shape of the bracket upper surface 24A, the bracket front surface 24C, and the bracket rear surface 24D, and the lower end portion of the outer flange portion 24H is outside the second floor cross member 16. It is joined to the inner side vertical wall portion 26C by spot welding or the like across the flange portion 16C. Further, the upper end portion of the outer flange portion 24H is joined to the inner side vertical wall portion 26C by spot welding or the like with an outer flange portion 30E of the diagonal member 30 described later interposed therebetween.

  In the present embodiment, the outer flange portion 24H is joined only to the inner side vertical wall portion 26C of the rocker inner panel 26. However, the present invention is not limited to this. For example, the outer flange portion 24H extends further upward. Alternatively, it may be bent outward in the vehicle width direction and joined to the inner side upper wall portion 26D of the rocker inner panel 26 by spot welding or the like. In this case, the joining strength between the rocker inner panel 26 and the outer sheet mounting bracket 24 can be further increased.

  Next, the diagonal member 30 provided inside the outer sheet mounting bracket 24 will be described. As shown in FIG. 3, the diagonal member 30 includes a plate-shaped diagonal member main body 30 </ b> A that extends obliquely downward from the rocker inner panel 26 toward the second floor cross member 16. The diagonal body 30A is formed in a substantially rectangular shape in plan view, and the lower end of the diagonal body 30A is an inner flange that is bent inward in the vehicle width direction along the upper surface of the second floor cross member 16. Part 30B. Here, as shown in FIG. 2, the inner flange portion 30B is disposed between the inner flange portion 24E of the outer seat mounting bracket 24 and the second floor cross member 16, and the inner flange portion 24E Joined to the joint with the two-floor cross member 16 by spot welding or the like.

  As shown in FIG. 3, the upper end portion of the diagonal member main body 30A is located at the upper part of the inner side vertical wall portion 26C of the rocker inner panel 26, and extends upward from the upper end portion of the diagonal member main body portion 30A. The outer flange portion 30E is extended. In addition, you may provide an extension part toward the vehicle width direction outer side from the upper end part of the outer side flange part 30E.

  Here, as shown in FIG. 2, the outer flange portion 30 </ b> E is formed in substantially the same shape as the outer flange portion 24 </ b> H and the extension portion 24 </ b> I of the outer seat mounting bracket 24. It arrange | positions between the part 24I and the inner side vertical wall part 26C. The outer flange portion 30E and the extension portion 24I are joined to the joint portion between the outer flange portion 24H and the inner side vertical wall portion 26C and the joint portion between the extension portion 24I and the inner side upper wall portion 26D by spot welding or the like. ing.

  As shown in FIG. 3, a front flange portion 30 </ b> C that is bent downward from the diagonal material body 30 </ b> A is provided at the end of the diagonal material body 30 </ b> A on the vehicle front side. The front flange portion 30C is orthogonal to the diagonal main body 30A, and the length in the vehicle vertical direction gradually increases from the upper end portion toward the lower end portion. Further, the lower end portion 30G of the front flange portion 30C overlaps the front surface of the second floor cross member 16 in the vehicle front-rear direction, and is joined by spot welding or the like. Further, as shown in FIG. 7, the front flange portion 30 </ b> C is joined to the inside of the bracket front surface 24 </ b> C of the outer seat mounting bracket 24 by spot welding or the like.

  On the other hand, a rear flange portion 30D bent downward from the diagonal material body portion 30A is provided at the end of the diagonal material body portion 30A on the vehicle rear side, and the lower end portion of the rear flange portion 30D is located on the front side. Like the flange portion 30C, it is joined to the rear surface of the second floor cross member 16 by spot welding or the like. The rear flange portion 30D is joined to the inner side of the bracket rear surface 24D of the outer seat mounting bracket 24 by spot welding or the like. Thereby, the cross section which cut | disconnected the junction part of the rocker inner panel 26 and the 2nd floor cross member 16 along the vehicle front-back direction becomes a structure provided with three closed cross sections.

  In addition, in this embodiment, although each member was joined by spot welding etc., it is not restricted to this, You may join by another method, for example, you may join using an adhesive agent, laser welding, You may join using a rivet etc. Moreover, you may join using fasteners, such as a volt | bolt and a nut.

  Further, in this embodiment, the diagonal member 30 is provided inside the outer seat mounting bracket 24 disposed at the outer end of the second floor cross member 16 in the vehicle width direction. A similar diagonal member 30 may also be provided inside the inner sheet mounting bracket 22 arranged at the inner end in the width direction. Furthermore, in this embodiment, the bolt hole 18D is formed in the inner seat mounting bracket 22, and the bolt rail 24J is formed in the outer seat mounting bracket 24 so that the seat rail can be mounted. However, the present invention is not limited thereto, and a bracket for fixing the seat rail may be separately prepared without forming the bolt hole 18D and the bolt hole 24J.

(Action and effect)
Next, operations and effects of the vehicle lower structure 10 of the present embodiment will be described with reference to FIGS. In addition, the code | symbol S in a figure shows the front seat schematically, and the code | symbol 40 is a weld nut. Further, the illustration of the seat rail that supports the front seat S and the bolt that fixes the seat rail is omitted.

  As shown in FIG. 5, when a collision load F is input to the rocker outer panel 28 of the rocker 14 on the right side of the vehicle at the time of a side collision of the vehicle, a part of the collision load is transferred from the rocker outer panel 28 to the front bulkhead 32 and the rear side. It is transmitted to the rocker inner panel 26 via the bulkhead 34. The remaining collision load is directly transmitted to the rocker inner panel 26 from the outer side lower flange portion 28A and the outer side upper flange portion 28E of the rocker outer panel 28.

  The collision load transmitted to the rocker inner panel 26 is distributed and transmitted to the floor panel 12, the first floor cross member 18, the second floor cross member 16, and the outer seat mounting bracket 24. Here, in this embodiment, since the diagonal member 30 is provided, a part of the collision load transmitted from the upper end portion of the rocker inner panel 26 to the outer seat mounting bracket 24 is transmitted to the diagonal member 30. That is, a part of the collision load is distributed and transmitted to the bracket upper surface 24A of the outer sheet mounting bracket 24 and the diagonal member main body 30A of the diagonal member 30 as indicated by arrows in the drawing. Thereby, compared with the case where the diagonal member 30 is not provided, the collision load transmitted to the upper surface of the outer seat mounting bracket 24 is reduced, and the outer seat mounting bracket 24 is prevented from collapsing in cross section. Can do.

  Subsequently, the load transmitted to the bracket upper surface 24A of the outer seat mounting bracket 24 is transmitted from the bracket upper surface 24A to the second floor cross member 16 through the bracket inner surface 24B as shown by an arrow F1 in FIG. Is done. Specifically, it is transmitted in a substantially vertical direction to the joint portion between the upper surface of the second floor cross member 16 and the bracket inner side surface 24B. Here, the load transmitted from the bracket inner surface 24B to the second floor cross member 16 is reduced as compared with the case where the diagonal member 30 is not provided.

  On the other hand, the load transmitted to the diagonal material body 30A of the diagonal material 30 is transmitted from the diagonal material body 30A to the second floor cross member 16 as indicated by an arrow F2. Specifically, the oblique material body 30A is transmitted in the extending direction (diagonally downward) to the joint portion between the upper surface of the second floor cross member 16 and the bracket inner side surface 24B. Thereby, the load applied to the upper surface of the second floor cross member 16 is a load F3 obtained by combining the load F1 transmitted from the bracket inner side surface 24B and the load F2 transmitted from the diagonal member main body 30A. Here, since F3 acts on the second floor cross member 16 in the direction from the vertical to the inner side in the vehicle width direction, the vertical load is suppressed from being concentrated on the second floor cross member 16. That is, it is possible to prevent the second floor cross member 16 from being damaged and impeding the transmission of the collision load during a side collision, and to effectively transmit the collision load to the second floor cross member 16.

  Further, in the present embodiment, the rocker outer panel 28 and the rocker inner panel 26 are connected by the front bulkhead 32 and the rear bulkhead 34, so that the bulkhead is joined only to the rocker outer panel 28 or the rocker inner panel 26. Compared to the above, it is possible to increase the rigidity of the rocker 14 and to effectively transmit the collision load at the time of a side collision. As a result, it is possible to reduce the intrusion amount of the collision object at the time of a side collision.

  Furthermore, in the present embodiment, as shown in FIG. 7, the cross section of the outer seat mounting bracket 24 cut along the vehicle front-rear direction has three closed cross sections. Compared to the case where the outer seat mounting bracket 24 is not provided, the rigidity of the outer seat mounting bracket 24 against the load applied in the vehicle vertical direction can be increased. Thereby, it is possible to suppress the outer seat mounting bracket 24 from collapsing in cross section due to the vehicle vertical load applied from the seat and the occupant.

  In the present embodiment, the front flange portion 30C of the diagonal member main body 30A and the bracket front surface 24C of the outer seat mounting bracket 24 are joined, and the rear flange portion 30D and the bracket rear surface 24D are joined. However, the configuration is not limited thereto, and the front flange portion 30C and the rear flange portion 30D may not be provided. In this case, the trouble of joining the diagonal member 52 and the outer sheet mounting bracket 24 by spot welding or the like at the time of manufacture can be saved. When the front flange portion 30C and the rear flange portion 30D are not provided, the diagonal member body 30A is made thicker or a bead is set on the diagonal member body 30A to ensure the rigidity of the diagonal member 30. Is preferred.

  Although the vehicle lower structure according to the embodiment of the present invention has been described above, it is needless to say that the present invention can be implemented in various modes without departing from the gist of the present invention.

10 Vehicle Lower Structure 14 Rocker 16 Second Floor Cross Member (Floor Cross Member)
24 Outer seat mounting bracket (connecting member)
24A Bracket upper surface (horizontal wall)
24B Bracket inner side (vertical wall)
24C Bracket front (side wall)
24D Bracket rear surface (side wall)
26 Rocker inner panel 28 Rocker outer panel 30 Diagonal material 32 Front bulkhead (reinforcing member)
34 Rear bulkhead (reinforcing member)
50 Vehicle lower structure 52 Diagonal material

Claims (5)

A pair of rockers provided at both ends in the vehicle width direction of the lower part of the vehicle and extending in the vehicle front-rear direction;
A floor cross member extending in the vehicle width direction between the pair of rockers and having one end joined to a lower portion of the rocker;
The side surface in the vehicle width direction of the rocker and the upper portion of the floor cross member are connected, and at least a lateral wall portion extending inward in the vehicle width direction from the rocker, and extending from the lateral wall portion to the vehicle lower side. And a vertical wall part joined to the floor cross member, and a connecting member,
It is arranged between the connecting member and the upper part of the floor cross member,
Extending obliquely downward from the joint between the rocker and the lateral wall toward the upper portion of the floor cross member, and the lower end at substantially the same position in the vehicle width direction as the joint between the vertical wall and the floor cross member A diagonal member joined to the top of the floor cross member;
Have
The diagonal member includes an outer flange portion disposed on the outer side in the vehicle width direction, and an inner flange portion disposed on the inner side in the vehicle width direction,
Further, the outer flange portion extends along an inner side vertical wall portion extending in a vehicle vertical direction of a rocker inner panel disposed on the inner side in the vehicle width direction of the rocker from an outer end portion in the vehicle width direction of the connecting member. It is formed in substantially the same shape as the outer flange part of the bent connecting member and is joined in a state sandwiched between the outer flange part of the connecting member and the inner side vertical wall part,
The inner flange portion is formed in substantially the same shape as the inner flange portion of the connecting member bent inward in the vehicle width direction along the upper surface of the floor cross member from the lower end portion of the vertical wall portion of the connecting member. The vehicle lower part structure joined in the state pinched | interposed between the said inner side flange part of the said connection member, and the said floor cross member . The vehicle lower structure according to claim 1 , wherein the connecting member is a seat mounting bracket that supports a vehicle seat. The seat mounting bracket includes a side wall portion that extends downward from both ends of the lateral wall portion in the vehicle front-rear direction and is joined to the floor cross member.
The vehicle lower structure according to claim 2, wherein both end portions of the diagonal member in the vehicle front-rear direction are joined to the side wall portion. A reinforcing member is provided inside the rocker,
The vehicle lower structure according to any one of claims 1 to 3, wherein the reinforcing member is joined to the rocker at a position that overlaps when a joint portion between the rocker and the lateral wall portion is projected in a vehicle width direction. . The rocker is configured to cross-sectionally closed shape and a rocker outer panel that is disposed on the rocker inner panel and the vehicle width direction outer side,
The vehicle lower structure according to claim 4, wherein the reinforcing member is connected to the rocker inner panel and the rocker outer panel.

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