JP6826490B2 - Body undercarriage - Google Patents

Description

The present invention relates to a vehicle body lower structure.

As a vehicle body lower structure, for example, a floor panel is erected between a left side sill and a right side sill, and a battery pack is mounted below the floor panel. A battery is housed inside the battery pack. The batteries in the battery pack must be protected from loads entered from the side of the vehicle. Therefore, the height of the side sill is increased and an energy absorbing member is provided inside the side sill. By absorbing the impact load input from the side of the vehicle with the energy absorbing member, it becomes possible to protect the battery (that is, the underfloor mounted component) in the battery pack from the impact load (see, for example, Patent Document 1). ..

U.S. Pat. No. 8,702,161

However, in the vehicle body lower structure of Patent Document 1, the height of the side sill is increased. Therefore, the upper part of the side sill is located above the floor panel. For this reason, the side sill becomes an obstacle when the occupant gets on and off, and it is difficult to ensure good occupant getting on and off.

Therefore, the present invention provides a vehicle body lower structure capable of protecting underfloor mounted parts from an impact load input from the side of the vehicle while ensuring good occupant boarding / alighting performance.

In order to solve the above problems, the invention according to claim 1 is a side sill (for example, the left side portion 10a and the right side portion 10b) of both sides (for example, the left side portion 10a and the right side portion 10b) of the vehicle (for example, the vehicle Ve of the embodiment). A vehicle body provided with a floor panel (for example, the floor panel 16 of the embodiment) arranged between the left side sill 14 and the right side sill 15 of the embodiment and erected on the upper portion of each side sill (for example, the upper side sill 82 of the embodiment). In the lower structure (for example, the vehicle body lower structure 12 of the embodiment), the floor panel is provided on the upper surface of the floor panel (for example, the upper surface 16a of the floor panel of the embodiment), extends in the vehicle width direction, and is erected between the side sills. A floor cross member (for example, the first to third floor cross members 34 to 36 of the embodiment) having a member upper part (for example, the member upper part 101 of the embodiment) located above the upper part of the side sill, and the floor cross member. Is erected on the inner wall of the side sill (for example, the inner wall 81 of the side sill of the embodiment) and the lower surface of the floor panel (for example, the lower surface 16b of the floor panel of the embodiment), and the vehicle is erected from the lower surface to the inner wall. A gusset extending downward in the width direction (for example, the first to third gussets 61 to 63 of the embodiment) is provided, and the upper part of the member is directed outward in the vehicle width direction to the upper part of the side sill. upper inclined portion extending downward slope (e.g., on the inclined portions 108 of the embodiment) have a said floor cross member, the end member joined to the order from the outside in the vehicle width direction to the center (e.g., the embodiment End members 171,301), straight members (eg, straight members 172,302 of the embodiment), and central members (eg, central members 173,303 of the embodiment), with said end members. The first joint portion with the straight portion member (for example, the first joint portion 184 of the embodiment) and the second joint portion between the straight portion member and the central portion member (for example, the second joint portion 196 of the embodiment). ) Is joined to a fastening bracket (for example, the outer fastening bracket 141 and the inner fastening bracket 142 of the embodiment) to which the underfloor mounting component (for example, the battery pack 28 of the embodiment) arranged below the floor panel is connected. that, characterized in that.

By erection of the floor panel on the upper part of the side sill in this way, the upper part of the side sill and the upper surface of the floor panel can be made the same height. As a result, the side sill does not get in the way when the occupant gets on and off, and the occupant can get on and off well.

In addition, the floor cross member has an upwardly inclined portion on the upper part of the member, and the upperly inclined portion is extended downward to the upper part of the side sill toward the outside in the vehicle width direction. Furthermore, the gusset was extended downward from the lower surface of the floor panel to the inner wall of the side sill toward the outside in the vehicle width direction. Therefore, it is possible to form a cross section substantially the same as the cross section of the floor cross member at the upper inclined portion and the gusset. Further, the cross section formed by the upper inclined portion and the gusset can be a cross section having substantially the same size as the floor cross member.
As a result, when an impact load is input from the side of the vehicle, the load can be transmitted from the inner bulkhead to the gusset via the inner wall of the side sill. By transmitting the load transmitted to the gusset to the floor cross member and supporting the load with the floor cross member, it is possible to protect the underfloor mounted parts from the impact load input from the side of the vehicle.

Further, by providing the floor cross member on the upper surface of the floor panel, the floor cross member can be removed from below the floor panel. As a result, the capacity of the underfloor-mounted parts such as the battery pack provided below the floor panel can be increased.
Here, the end members of the floor cross member are joined to the side sill. Further, the central member of the floor cross member is formed according to, for example, a floor tunnel. Therefore, the end member and the center member have a relatively complicated shape. On the other hand, the straight line member can be suppressed to a relatively simple shape.
The floor cross member is divided into three members: an end member, a straight member, and a central member. Therefore, for example, an end member or a center member having a complicated shape can be drawn (drawed), and a straight member having a simple shape can be bent (bent). By bending the straight portion member in this way, the manufacturing cost of the floor cross member can be reduced.
Further, it is possible to optimize the collision mode by making the strengths of the end member, the straight member, and the center member different. In this case, it is required to devise a method for ensuring the strength of the first joint portion between the end member and the straight portion member and the second joint portion between the straight portion member and the central portion member. Therefore, we decided to join the fastening bracket to the first joint and the second joint. The fastening bracket uses a high-strength member to support the underfloor mounting parts.
As a result, by joining the fastening bracket to the first joint and the second joint, the first joint and the second joint can be reinforced by the fastening bracket, and the load transmission performance of the floor cross member can be ensured. ..

According to the second aspect of the present invention, the floor cross member extends outward in the vehicle width direction from the upward inclined portion and is joined to the upper portion of the side sill (for example, the joint seat portion of the embodiment). It is characterized by having 177) and a bead (for example, the bead 178 of the embodiment) that extends in the vehicle width direction from the upper inclined portion to the joint seat portion and rises upward.

Here, the upward slope extends downward to the upper part of the side sill. Further, the joint seat portion extends from the upward inclined portion toward the outside in the vehicle width direction. The boundary between the upper inclined portion and the joint seat portion is bent to form a bent portion extending in the front-rear direction of the vehicle body.
Therefore, the bead was extended in the vehicle width direction from the upper inclined portion to the joint seat portion. Therefore, the bead can be extended so as to intersect (specifically, orthogonal to) the bent portion. As a result, the bent portion can be reinforced with a bead against the impact load input from the side of the vehicle to the joint portion.
That is, when an impact load is applied to the joint seat portion from the side of the vehicle, it is possible to prevent the bent portion from bending with a bead. As a result, the impact load can be transmitted from the joint seat portion to the upward inclined portion via the bead, and the load transmission can be prevented from being impaired.

According to the third aspect of the present invention, the floor cross member includes the upper inclined portion, a member front wall portion extending from the front side of the upper inclined portion to the floor panel (for example, the member front wall portion 102 of the embodiment). And a member rear wall portion extending from the rear side of the upper inclined portion to the floor panel (for example, the member rear wall portion 103 of the embodiment) is formed in a U shape, and the gusset has a vehicle width from the lower surface to the inner wall. A gusset inclined portion extending downward in the direction (for example, the gusset inclined portion 111 of the embodiment), a gusset front wall portion extending from the front side of the gusset inclined portion to the floor panel (for example, the gusset front wall of the embodiment). The floor cloth member and the gusset are formed in a U shape by the portion 112) and the gusset rear wall portion (for example, the gusset rear wall portion 113 of the embodiment) extending from the rear side of the gusset inclined portion described above to the floor panel. Is characterized in that the floor panels are joined in a state of being interposed.

As described above, the floor cross member is formed in a U shape at the upper inclined portion, the front wall and the rear wall. The gusset is formed in a U shape by the gusset inclined portion, the gusset front wall and the gusset rear wall. Further, the floor cross member and the gusset are joined with the floor panel interposed therebetween.
Therefore, a highly rigid closed cross section is formed by the floor cross member and the gusset. As a result, the impact load input from the side of the vehicle can be transmitted from the side sill to the floor cross member.

The invention according to claim 4 is a bulkhead provided inside the side sill (for example, outer space 88 and inner space 89 of the embodiment) and facing the inner wall (for example, first to third embodiments of the embodiment). The outer bulkheads 51 to 53 and the first to third inner bulkheads 55 to 57) are provided, and the portion of the inner wall facing the bulkhead (for example, a portion 81a facing the bulkhead of the embodiment) is described. It is characterized by having a gusset attached.

In this way, the bulkhead in the side sill faces the inner wall of the side sill. In addition, a gusset is attached so as to face the bulkhead. Therefore, the impact load input to the side sill from the side of the vehicle can be transmitted to the gusset via the bulkhead. As a result, the impact load input from the side of the vehicle can be transmitted to the floor cross member via the gusset and supported by the floor cross member. As a result, the underfloor mounted parts can be protected from the impact load input from the side of the vehicle.

In the invention according to claim 5, at least a pair of the floor cross members are provided at intervals in the front-rear direction of the vehicle body, and seats (for example, the driver seat 31 and the passenger seat 32 of the embodiment) are provided on the pair of floor cross members. It is characterized by being attached.

In this way, the seats are attached to the pair of floor cross members. The pair of floor cross members are erected on the side sills on both sides of the vehicle body. Therefore, the impact load input from the side of the vehicle can be supported by the pair of floor cross members. As a result, it is possible to prevent the side part of the vehicle body such as the side sill from being deformed to the seat, and it is possible to protect the occupant from the impact load in addition to the underfloor mounted parts.

According to the present invention, by installing the floor panel on the upper part of the side sill, the upper part of the side sill and the upper surface of the floor panel can be made the same height. As a result, the side sill does not get in the way when the occupant gets on and off, and the occupant can get on and off well.
Further, the upper slope of the floor cross member was extended downward to the upper part of the side sill, and the gusset was extended downward from the lower surface of the floor panel to the inner wall of the side sill. As a result, the underfloor mounted parts can be protected from the impact load input from the side of the vehicle.

It is a perspective view which shows the vehicle body lower structure in one Embodiment of this invention. It is a top view which shows the vehicle body lower structure in one Embodiment of this invention. It is a perspective view which shows the state which the seat is removed from the vehicle body lower structure in one Embodiment of this invention. It is sectional drawing which shows the state which the car body lower structure in one Embodiment of this invention is broken along the IV-IV line of FIG. It is sectional drawing which shows the expansion of the V part of FIG. 4 in the vehicle body lower structure in one Embodiment of this invention. It is a perspective view which shows the outer bulkhead and the inner bulkhead of the vehicle body lower structure in one Embodiment of this invention. It is an exploded perspective view which shows the outer bulkhead and the inner bulkhead of the vehicle body lower structure in one Embodiment of this invention. It is a perspective view which shows the 1st floor cross member and the 2nd floor cross member of the vehicle body lower structure in one Embodiment of this invention. It is an exploded perspective view which shows the 1st floor cross member and the 2nd floor cross member of the vehicle body lower structure in one Embodiment of this invention. It is a perspective view which shows the X part enlargement of FIG. 9 in the vehicle body lower structure in one Embodiment of this invention. It is sectional drawing which shows the enlargement of the XI part of FIG. 4 in the vehicle body lower structure in one Embodiment of this invention. It is sectional drawing which shows the XII part enlargement of FIG. 4 in the vehicle body lower structure in one Embodiment of this invention. It is a perspective view which shows the gusset of the vehicle body lower structure in one Embodiment of this invention. It is a perspective view which shows the state which was broken along the line XIIII-XIIII of FIG. 8 in the vehicle body lower structure in one Embodiment of this invention. It is a perspective view which shows in the state which the battery pack frame of the vehicle body lower structure in one Embodiment of this invention is broken. It is sectional drawing explaining an example which protects a battery from an impact load input from the side of a vehicle in the vehicle body lower structure in one Embodiment of this invention.

An embodiment of the present invention will be described with reference to the drawings. In the drawings, the arrow FR points to the front of the vehicle, the arrow UP points to the upper side of the vehicle, and the arrow LH points to the left side of the vehicle.
As shown in FIGS. 1 and 2, the vehicle body 10 includes a vehicle body lower structure 12 that constitutes a lower portion of the vehicle body 10. The vehicle body lower structure 12 includes a left side sill 14, a right side sill 15, a floor panel 16, a floor cross member unit 17, an outer bulkhead unit 18 on the left side, an inner bulkhead unit 19 on the left side, and an outer bulk on the right side. It includes a head unit 21, an inner bulkhead unit 22 on the right side, a gusset unit 24 on the left side, and a gusset unit 25 on the right side.

Further, the vehicle body lower structure 12 includes a battery pack (underfloor mounting component (that is, in-vehicle component)) 28 (see FIG. 4), a battery pack frame 29 (see FIG. 4), a driver seat 31, and a passenger seat 32. It has.
Since the vehicle body lower structure 12 is composed of members that are substantially symmetrical, the description of each component on the left side will be described below, and the description of each component on the right side will be omitted.

The left side sill 14 is provided on the left side portion 10a of both side portions of the vehicle body 10 and extends in the front-rear direction of the vehicle body. The right side sill 15 is provided on the right side portion 10b of both side portions of the vehicle body 10 and extends in the front-rear direction of the vehicle body.
A floor panel 16 is arranged between the left side sill 14 and the right side sill 15. The floor panel 16 is erected on the left side sill 14 and the right side sill 15. A floor cross member unit 17 is attached to the upper surface 16a of the floor panel 16. The floor cross member unit 17 includes a first floor cross member 34, a second floor cross member 35, and a third floor cross member 36.

The first floor cross member 34 is arranged on the front side of the vehicle body in the vehicle interior 38. The first floor cross member 34 is erected on the left side sill 14 and the right side sill 15 so as to face the vehicle width direction.
The second floor cross member 35 is arranged on the rear side of the vehicle body of the first floor cross member 34. The second floor cross member 35 is erected on the left side sill 14 and the right side sill 15 so as to face the vehicle width direction, and extends in parallel with the first floor cross member 34.
The third floor cross member 36 is arranged on the rear side of the vehicle body of the second floor cross member 35. The third floor cross member 36 is erected on the left side sill 14 and the right side sill 15 so as to face the vehicle width direction, and extends in parallel with the second floor cross member 35.

The first floor cross member 34, the second floor cross member 35, and the third floor cross member 36 are provided at intervals in the front-rear direction of the vehicle body, respectively. For example, a driver seat 31 is attached to the right half of the first floor cross member 34 and the second floor cross member 35 with fastening members such as bolts 37 and nuts. For example, a passenger seat 32 is attached to the left half of the first floor cross member 34 and the second floor cross member 35 with fastening members such as bolts 41 and nuts 42 (see FIG. 4). Further, a rear seat 43 is provided on the third floor cross member 36.

In this way, the driver seat 31 is attached to the right half of the first floor cross member 34 and the second floor cross member 35. Further, a passenger seat 32 is attached to the left half of the first floor cross member 34 and the second floor cross member 35. The first floor cross member 34 and the second floor cross member 35 are erected on the left side sill 14 and the right side sill 15, respectively.
The first floor cross member 34, the second floor cross member 35, and the third floor cross member 36 are similar members. Hereinafter, the second floor cross member 35 will be described in detail, and the first and third floor cloths will be described. Detailed description of members 34 and 36 will be omitted. The second floor cross member 35 will be abbreviated as "floor cross member 35" below.

The outer bulkhead unit 18 on the left side includes a first outer bulkhead 51, a second outer bulkhead 52, and a third outer bulkhead 53.
The first outer bulkhead 51 is arranged on an extension line of the first floor cross member 34. The second outer bulkhead 52 is arranged on an extension line of the second floor cross member 35. The third outer bulkhead 53 is arranged on an extension line of the third floor cross member 36.
The first outer bulkhead 51, the second outer bulkhead 52, and the third outer bulkhead 53 are similar members. Hereinafter, the second outer bulkhead 52 will be described in detail as the "outer bulkhead 52", and the first , The detailed description of the third outer bulkheads 51 and 53 will be omitted.

As shown in FIG. 3, the inner bulkhead unit 19 on the left side includes a first inner bulkhead 55, a second inner bulkhead 56, and a third inner bulkhead 57.
The first inner bulkhead 55 is arranged on an extension line of the first floor cross member 34. The second inner bulkhead 56 is arranged on an extension line of the second floor cross member 35. The third inner bulkhead 57 is arranged on an extension line of the third floor cross member 36.
The first inner bulkhead 55, the second inner bulkhead 56, and the third inner bulkhead 57 are similar members. Hereinafter, the second inner bulkhead 56 will be described in detail as the "inner bulkhead 56", and the first , The detailed description of the third inner bulkheads 55 and 57 will be omitted.

Returning to FIG. 2, the left gusset unit 24 includes a first gusset 61, a second gusset 62, and a third gusset 63.
The first gusset 61 is arranged below the inclined portion 99 on the left end side of the first floor cross member 34. The second gusset 62 is arranged below the inclined portion 107 (see also FIG. 4) on the left end side of the second floor cross member 35. The third gusset 63 is arranged below the inclined portion 109 on the left end side of the third floor cross member 36.
The first gusset 61, the second gusset 62, and the third gusset 63 are similar members. Hereinafter, the second gusset 62 will be described in detail as "gusset 62", and the first gusset 61 and the third gusset 63 will be described in detail. Is omitted.

As shown in FIGS. 4 and 5, the left side sill 14 includes a side sill outer 65, a side sill inner 66, and a stiffener 67.
The side sill outer 65 is provided on the outer side in the vehicle width direction. The side sill outer 65 has an outer bulging portion 71, an upper flange 72, and a lower flange 73. The outer bulging portion 71 bulges outward in the vehicle width direction from the upper flange 72 and the lower flange 73. A reinforcing member 74 is attached to the inner surface of the outer bulging portion 71. The upper flange 72 projects upward from the upper end of the outer bulging portion 71. The lower flange 73 projects downward from the lower end of the outer bulging portion 71.

The side sill inner 66 is provided inside the side sill outer 65 in the vehicle width direction. The side sill inner 66 has an inwardly bulging portion 76, an upper flange 77, and a lower flange 78. The inward bulging portion 76 bulges inward in the vehicle width direction from the upper flange 77 and the lower flange 78. The inner bulging portion 76 is formed in a U-shaped cross section by the inner wall 81, the upper portion 82, and the lower portion 83. A reinforcing member 79 is attached to the inner surface of the inwardly bulging portion 76. The upper flange 77 projects upward from the outer end of the upper portion 82. The lower flange 78 projects downward from the outer end of the lower 83.

The stiffener 67 is interposed between the side sill outer 65 and the side sill inner 66. The stiffener 67 is formed in a flat plate shape and is interposed between the side sill outer 65 and the side sill inner 66. Specifically, the upper flange 72 of the side sill outer 65 and the upper flange 77 of the side sill inner 66 are joined in a state where the upper side portion 67a of the stiffener 67 is sandwiched between them. Further, the lower flange 73 of the side sill outer 65 and the lower flange 78 of the side sill inner 66 are joined in a state where the lower side portion 67b of the stiffener 67 is sandwiched between them. That is, the stiffener 67 is sandwiched between the side sill outer 65 and the side sill inner 66.

The left side sill 14 is formed in the outer shape of a rectangular frame by the side sill outer 65 and the side sill inner 66. The upper side portion 67a of the stiffener 67 is interposed between the upper flanges 72 and 77, and the lower side portion 67b of the stiffener 67 is interposed between the lower flanges 73 and 78, so that the stiffener 67 is arranged in the vertical direction.
An outer space 88 is formed between the side sill outer 65 and the stiffener 67. Further, an inner space 89 is formed between the side silina 66 and the stiffener 67.

As shown in FIGS. 6 and 7, the outer bulkhead 52 is arranged in the outer space 88 between the side sill outer 65 and the stiffener 67. The outer bulkhead 52 has a side wall 84, a bottom 85, and a joint flange 86. The side wall 84 has a front side wall 84a, a rear side wall 84b, an upper side wall 84c, and a lower side wall 84d. The side wall 84 is formed in a rectangular frame shape by the front side wall 84a, the rear side wall 84b, the upper side wall 84c, and the lower side wall 84d.
One end of the side wall 84 (the end on the side away from the stiffener 67) is closed by the bottom 85. The bottom 85 is formed in a rectangular shape. An opening 87 (see also FIG. 5) is opened in a rectangular shape at the other end of the side wall 84 (the end on the stiffener 67 side). A joint flange 86 is formed at the other end of the side wall 84.

The joint flange 86 has a front joint flange 86a, a rear joint flange 86b, an upper joint flange 86c, and a lower joint flange 86d.
The front joint flange 86a projects from the other end of the front side wall 84a toward the front of the vehicle body along the outer surface 67c of the stiffener 67. The rear joint flange 86b projects from the other end of the rear side wall 84b toward the rear of the vehicle body along the outer surface 67c of the stiffener 67. The upper joint flange 86c projects upward from the other end of the upper side wall 84c along the outer surface 67c of the stiffener 67. The lower joint flange 86d projects downward from the other end of the lower side wall 84d along the outer surface 67c of the stiffener 67.

That is, the joint flange 86 is provided on the entire circumference of the opening 87 at the other end of the side wall 84 on the opening 87 side. The front joint flange 86a, the rear joint flange 86b, the upper joint flange 86c, and the lower joint flange 86d constituting the joint flange 86 are arranged in contact with the outer surface 67c of the stiffener 67.
As described above, the outer bulkhead 52 is formed in a box shape (hereinafter, referred to as a box shape) having a polygonal cross section (specifically, a rectangular cross section) in which the opening 87 is opened on the stiffener 67 side.

The inner bulkhead 56 is arranged in the inner space 89 between the side bulkhead 66 and the stiffener 67. The inner bulkhead 56, like the outer bulkhead 52, has a side wall 91, a bottom 92, and a joint flange 93. The side wall 91 has a front side wall 91a, a rear side wall 91b, an upper side wall 91c, and a lower side wall 91d. The side wall 91 is formed in a rectangular frame shape by the front side wall 91a, the rear side wall 91b, the upper side wall 91c, and the lower side wall 91d.
One end of the side wall 91 (the end on the side away from the stiffener 67) is closed by the bottom 92. The bottom 92 is formed in a rectangular shape. An opening 94 is opened at the other end of the side wall 91 (the end on the stiffener 67 side). The opening 94 of the inner bulkhead 56 is opened in a rectangular shape having the same shape as the opening 87 of the outer bulkhead 52.
A joint flange 93 is formed at the other end of the side wall 91.

The joint flange 93 has a front joint flange 93a, a rear joint flange 93b, an upper joint flange 93c, and a lower joint flange 93d. The front joint flange 93a projects from the other end of the front side wall 91a toward the front of the vehicle body along the inner surface 67d of the stiffener 67. The rear joint flange 93b projects from the other end of the rear side wall 91b toward the rear of the vehicle body along the inner surface 67d of the stiffener 67. The upper joint flange 93c projects upward from the other end of the upper side wall 91c along the inner surface 67d of the stiffener 67. The lower joint flange 93d projects downward from the other end of the lower side wall 91d along the inner surface 67d of the stiffener 67.

That is, the joint flange 93 is provided on the entire circumference of the opening 94 at the other end of the side wall 91 on the opening 94 side. The front joint flange 93a, the rear joint flange 93b, the upper joint flange 93c, and the lower joint flange 93d constituting the joint flange 93 are arranged in contact with the inner surface 67d of the stiffener 67.
The inner bulkhead 56 has an opening 94 opened on the stiffener 67 side in a rectangular shape having the same shape as the opening 87 of the outer bulkhead 52, and is formed in a box shape having a polygonal cross section (rectangular cross section in the embodiment). ..

In a state where the joint flange 86 of the outer bulkhead 52 is in contact with the outer surface 67c of the stiffener 67 and the joint flange 93 of the inner bulkhead 56 is in contact with the inner surface 67d of the stiffener 67, the joint flange 86 and the joint flange 93 touch the stiffener 67. Overlaid through. The superposed joint flange 86 and the joint flange 93 are joined to each other via a stiffener 67.
As a result, the outer bulkhead 52 and the inner bulkhead 56 are attached to the stiffener 67 in a state of being overlapped in the vehicle width direction. Further, the outer bulkhead 52 and the inner bulkhead 56 are provided so as to overlap the floor cross member 35 in the vehicle width direction.

In this state, the outer bulkhead 52 extends in a direction in which the side wall 84 is separated from the stiffener 67 outward in the vehicle width direction. Further, in the outer bulkhead 52, one end of the side wall 84 on the side away from the stiffener 67 is closed by the bottom 85. The inner bulkhead 56 extends in a direction in which the side wall 91 is separated from the stiffener 67 inward in the vehicle width direction. Further, in the inner bulkhead 56, one end of the side wall 91 on the side away from the stiffener 67 is closed by the bottom 92.

As shown in FIGS. 2 and 5, the outer bulkhead 52 and the inner bulkhead 56 are provided so as to overlap the floor cross member 35 in the vehicle width direction. Therefore, when the impact load F1 is input from the side of the vehicle Ve, the outer bulkhead 52 and the inner bulkhead 56 can be crushed by the impact load F1. Further, the load F2 passing through the outer bulkhead 52 and the inner bulkhead 56 can be satisfactorily supported by the floor cross member 35.
In this way, the outer bulkhead 52 and the inner bulkhead 56 can be crushed by the impact load F1 input from the side of the vehicle Ve to absorb the impact energy.

The remaining load F2 absorbed by the outer bulkhead 52 and the inner bulkhead 56 can be supported by the first floor cross member 34 and the floor cross member (that is, the second floor cross member) 35. As a result, it is possible to prevent the vehicle body side portion such as the left side sill 14 from being deformed to the passenger seat 32. Further, it is possible to prevent the vehicle body side portion such as the right side sill 15 from being deformed to the driver seat 31.
That is, the occupants of the passenger seat 32 and the driver seat 31 can be protected from the impact load F1.

Returning to FIG. 7, the stiffener 67 has a hole 96. The hole 96 is formed at a portion corresponding to the opening 87 of the outer bulkhead 52 and the opening 94 of the inner bulkhead 56. By forming the hole 96 in the stiffener 67, when the inside of the left side sill 14 is electrodeposited, the electrodeposition paint can be satisfactorily guided to the inside of the left side sill 14 by using the hole 96. As a result, the electrodeposition paint can be easily adhered to the inside of the left side sill 14.
Further, by forming the hole 96 in the stiffener 67, the stiffener 67 can be made lighter, and the vehicle body 10 can be made lighter.

As shown in FIGS. 4 and 6, the left side portion 16c of the floor panel 16 is attached to the upper portion (upper surface) 82 of the inwardly bulging portion 76 of the side sill inner 66. The upper portion 82 of the inwardly bulging portion 76 is a portion to be the upper portion of the left side sill 14. Hereinafter, the upper part of the left side sill 14 is referred to as "side sill upper part 82".
The floor panel 16 is formed flat. Further, the left side portion 16c of the floor panel 16 is attached to the upper side sill 82. Therefore, the floor panel 16 is arranged at the same height as the side sill upper portion 82. As a result, the left side sill 14 does not get in the way when the occupant gets on and off, and the occupant can get on and off well.

A floor cross member 35 is provided on the upper surface 16a of the floor panel 16. The floor cross member 35 has a member upper portion 101, a member front wall portion 102, a member rear wall portion 103, a member front flange 104, and a member rear flange 105.
The member front wall portion 102 projects downward from the front side of the member upper portion 101 toward the floor panel 16. The member rear wall portion 103 projects downward from the rear side of the member upper portion 101 toward the floor panel 16. The floor cross member 35 is formed in a U-shaped cross section at the member upper portion 101, the member front wall portion 102, and the member rear wall portion 103.
The member front flange 104 projects from the lower side of the member front wall portion 102 to the front of the vehicle body along the upper surface 16a of the floor panel 16. The member rear flange 105 projects from the lower side of the member rear wall portion 103 to the rear of the vehicle body along the upper surface 16a of the floor panel 16.

The floor cross member 35 is attached to the upper surface 16a of the floor panel 16 by joining the member front flange 104 and the member rear flange 105 to the upper surface 16a of the floor panel 16. In this state, the member upper portion 101 of the floor cross member 35 is located above the side sill upper portion 82.

As shown in FIGS. 8 and 9, the floor cross member 35 is formed substantially symmetrically (see also FIG. 2). Therefore, the left side portion of the floor cross member 35 will be described in detail below, and the description of the right side portion will be omitted. The floor cross member 35 includes an end member 171, a straight line member 172, and a center member 173 that are joined in order from the outside in the vehicle width direction toward the center.
The end member 171 is arranged on the left outer side in the vehicle width direction, and extends inward in the vehicle width direction from the left side sill 14. The straight portion member 172 extends inward in the vehicle width direction from the inner end portion of the end member 171. The central member 173 extends inward in the vehicle width direction from the inner end of the straight member 172. The central member 173 is arranged so as to straddle the floor tunnel 192 of the floor panel 16.
Further, the floor cross member 35 is provided with an outer fastening bracket (fastening bracket) 141 and an inner fastening bracket (fastening bracket) 142.

The first floor cross member 34 is provided at a predetermined interval in front of the vehicle body of the floor cross member (that is, the second floor cross member) 35. The first floor cross member 34 is formed substantially symmetrically like the second floor cross member 35.
Similar to the second floor cross member 35, the first floor cross member 34 includes an end member 301, a straight portion member 302, and a central portion member 303 that are sequentially joined from the outside in the vehicle width direction toward the center. .. Further, the first floor cross member 34 is provided with an outer fastening bracket (fastening bracket) 304 and an inner fastening bracket (fastening bracket) 305.

The end member 301 is formed in the same manner as the end member 171 of the floor cross member 35. The straight portion member 302 is formed in the same manner as the straight portion member 172 of the floor cross member 35. The central member 303 is formed in the same manner as the central member 173 of the floor cross member 35.
Further, the outer fastening bracket 304 is formed in the same manner as the outer fastening bracket 141 of the floor cross member 35. The inner fastening bracket 305 is formed in the same manner as the inner fastening bracket 142 of the floor cross member 35.
Therefore, detailed description of the end member 301, the straight line member 302, the center member 303, the outer fastening bracket 304, and the inner fastening bracket 305 of the first floor cross member 34 will be omitted.

As shown in FIG. 10, the end member 171 has an inclined portion 107 and a horizontal portion 175. The inclined portion 107 is arranged on the left side sill 14 side.
The inclined portion 107 has an upper inclined portion 108, a joint seat portion 177, and a bead 178.
The upper inclined portion 108 is a portion forming an upper portion of the inclined portion 107.
The joint seat portion 177 extends horizontally from the outer end portion 108a of the upper inclined portion 108 toward the outside in the vehicle width direction and is joined to the side sill upper portion 82.

Here, the upper inclined portion 108 extends downward from the outer end of the horizontal portion 175 to the upper portion 82 of the side sill. Therefore, the boundary between the upper inclined portion 108 and the joint seat portion 177 is bent to form a bent portion 179 extending in the front-rear direction of the vehicle body. Therefore, when the impact load F1 is input from the side of the vehicle Ve, it is conceivable that the bent portion 179 is bent by the input impact load F1. Therefore, the bead 178 was extended in the vehicle width direction from the upper inclined portion 108 to the joint seat portion 177.

The bead 178 extends outward in the vehicle width direction from a portion 108b in the middle of the upper inclined portion 108 to the outer edge of the joint seat portion 177. The bead 178 is formed so as to bulge upward. A plurality of bead 178s are formed, for example, at intervals in the front-rear direction of the vehicle body. In the embodiment, an example in which two beads 178 are formed will be described, but the number of beads 178 can be arbitrarily selected. It is also possible to select one bead 178.

A bead 178 extends in the vehicle width direction from the upper inclined portion 108 to the outer edge of the joint seat portion 177. Therefore, the bead 178 is extended so as to intersect (specifically, orthogonal to) the bent portion 179. As a result, the bent portion 179 can be reinforced by the bead 178 with respect to the impact load F1 input from the side of the vehicle Ve to the joint portion.
That is, the bead 178 can prevent the bent portion 179 from bending when the impact load F1 is input to the joint seat portion 177. As a result, the impact load F1 can be transmitted from the joint seat portion 177 to the upward inclined portion 108 via the bead 178, so that the load transmission is not impaired.

Here, the upper inclined portion 108 is a portion forming the upper portion of the inclined portion 107. The upper inclined portion 108 extends downward to the upper portion 82 of the side sill toward the outside in the vehicle width direction. The outer end of the inclined portion 107 is closed by the upper inclined portion 108.
The outer end 108a of the upper inclined portion 108 is located at the upper portion 82 of the side sill. The joint seat portion 177 is joined to the side sill upper portion 82 via the left side portion 16c of the floor panel 16. The member front flange 104 (specifically, the end 104a of the member front flange 104) and the member rear flange 105 (specifically, the end 105a of the member rear flange 105) of the end member 171 are the floor panel 16. It is joined to the left side portion 16c.
In this way, the outer end portion (that is, the joint seat portion 177) of the inclined portion 107 is joined to the side sill upper portion 82 via the left side portion 16c of the floor panel 16.

The horizontal portion 175 extends parallel to the floor panel 16 from the inner end portion 107a of the inclined portion 107 toward the inside in the vehicle width direction. The left side seat mounting portion 181 of the passenger seat 32 (see FIG. 11) is mounted on the upper portion 175a of the horizontal portion 175 with bolts 41 and nuts 42.
The end member 171 is formed into a relatively complicated shape by closing the outer end portion of the inclined portion 107 with the upper inclined portion 108.

As shown in FIGS. 8 and 9, the inner end portion 171a of the end portion member 171 and the outer end portion 172a of the straight portion member 172 are joined in a superposed state. By joining the inner end portion 171a of the end portion member 171 and the outer end portion 172a of the straight portion member 172, the first joint portion 184 is formed by the overlapped inner end portion 171a and the outer end portion 172a. ing. An outer fastening bracket 141 is joined to the first joint portion 184.

As shown in FIGS. 10 and 11, the outer fastening bracket 141 has a bottom portion 185, an outer leg portion 186, an inner leg portion 187, an outer upper flange 188, and an inner upper flange 189.
The bottom portion 185 is arranged along the floor panel 16 and is fastened to the upper portion 133b of the fastening member 133 via the floor panel 16 by bolts 165 and nuts 166. The outer leg portion 186 is raised from the outer portion of the bottom portion 185 to the upper portion 175a of the horizontal portion 175 (that is, the inner end portion 171a of the end member 171). The inner leg portion 187 is raised from the inner portion of the bottom portion 185 to the straight portion member 172. The outer fastening bracket 141 is formed in a U-shaped cross section at the bottom portion 185, the outer leg portion 186, and the inner leg portion 187.

From the upper end of the outer leg portion 186, the outer upper flange 188 extends outward in the vehicle width direction along the outer surface of the inner end portion 171a. The outer upper flange 188 is joined to the first joint portion 184. Specifically, the outer upper flange 188 is joined in a state of being sandwiched between the inner end portion 171a of the end portion member 171 and the outer end portion 172a of the straight portion member 172.
The bottom portion 185 of the outer fastening bracket 141 is fastened to the upper portion 133b of the fastening member 133 via the floor panel 16 by bolts 165 and nuts 166. The outer fastening bracket 141 is made of a high-strength member for supporting the battery pack 28. Therefore, the first joint portion 184 is reinforced by the outer upper flange 188.
From the upper end of the inner leg portion 187, the inner upper flange 189 extends inward in the vehicle width direction along the inner surface of the straight portion member 172. The inner upper flange 189 is joined to the straight line member 172.

As shown in FIGS. 9 and 12, the central member 173 is arranged so as to intersect (orthogonally) the floor tunnel 192 of the floor panel 16 and is attached so as to straddle the floor tunnel 192. The central portion member 173 has an upper portion 173b extending in the vehicle width direction and a raised portion 194 raised in the center in the vehicle width direction. The right side seat mounting portion 182 of the passenger seat 32 (see FIG. 11) is mounted on the upper portion 173b of the central portion member 173 with bolts 41 and nuts 42.
The raised portion 194 is formed in a U shape along the floor tunnel 192. That is, the raised portion 194 is formed in a relatively complicated shape.
The left end portion 173a of the central portion member 173 and the inner end portion 172b of the straight portion member 172 are joined in a superposed state. By joining the left end portion 173a of the central portion member 173 and the inner end portion 172b of the straight portion member 172, the second joint portion 196 is formed by the left end portion 173a and the inner end portion 172b. An inner fastening bracket 142 is joined to the second joint portion 196.

The inner fastening bracket 142 has a bottom portion 202, an outer leg portion 203, an inner leg portion 204, an outer upper flange 205, and an inner upper flange 206, similarly to the inner fastening bracket 142.
The bottom portion 202 is arranged along the floor panel 16 and is fastened to the upper portion 133b of the fastening member 133 by bolts 167 and nuts 168 via the floor panel 16. The outer leg portion 203 is raised from the outer portion of the bottom portion 202 to the straight portion member 172. The inner leg portion 204 is raised from the inner portion of the bottom portion 202 to the upper portion 173b of the central portion member 173. The inner fastening bracket 142 is formed in a U-shaped cross section at the bottom portion 202, the outer leg portion 203, and the inner leg portion 204.

The inner upper flange 206 extends inward in the vehicle width direction from the upper end of the inner leg portion 204 along the outer surface of the upper portion 173b of the central portion member 173. The inner upper flange 206 is joined to the second joint portion 196 in a state of being sandwiched between the left end portion 173a and the inner end portion 172b. The bottom portion 202 of the inner fastening bracket 142 is fastened to the upper portion 133b of the fastening member 133 via the floor panel 16 by bolts 167 and nuts 168. The inner fastening bracket 142 uses a high-strength member to support the battery pack 28. Therefore, the second joint portion 196 is reinforced by the inner upper flange 206.
The outer upper flange 205 extends outward from the upper end of the outer leg portion 203 along the inner surface of the straight portion member 172 in the vehicle width direction. The outer upper flange 205 is joined to the straight portion member 172.

A raised portion 194 is formed in a U shape on the central portion member 173. Therefore, the central member 173 is formed in a relatively complicated shape.
On the other hand, the straight portion member 172 extends linearly from the end portion member 171 to the central portion member 173. Therefore, the straight portion member 172 is formed in a relatively simple shape.

Here, the end member 171 of the floor cross member 35 is joined to the left side sill 14. Further, the central member 173 of the floor cross member 35 is formed in accordance with, for example, the floor tunnel 192. Therefore, the end member 171 and the center member 173 are formed in a relatively complicated shape. On the other hand, the straight portion member 172 is suppressed to a relatively simple shape.
In this way, the floor cross member 35 is divided into three members: an end member 171 and a straight line member 172, and a central member 173. Therefore, for example, the end member 171 and the center member 173 having a complicated shape can be drawn (drawed), and the straight member 172 having a simple shape can be bent (bent). By bending the straight portion member 172 in this way, the manufacturing cost of the floor cross member 35 can be reduced.

Further, it is possible to optimize the collision mode by making the strengths of the end member 171, the straight line member 172, and the center member 173 different. In this case, a device for ensuring the strength of the first joint portion 184 (see FIG. 11) between the end member 171 and the straight portion member 172 and the second joint portion 196 between the straight portion member 172 and the central portion member 173 is required. Be done. Therefore, the outer fastening bracket 141 is joined to the first joint portion 184. Further, the inner fastening bracket 142 is joined to the second joint portion 196. The outer fastening bracket 141 and the inner fastening bracket 142 are made of high-strength members to support the battery pack 28.
Therefore, the outer fastening bracket 141 is joined to the first joining portion 184, and the inner fastening bracket 142 is joined to the second joining portion 196, so that the first joining portion 184 is reinforced by the outer fastening bracket 141 and the second joining is performed. The portion 196 is reinforced by the inner fastening bracket 142. As a result, the load transmission performance of the floor cross member 35 in the vehicle width direction can be ensured, and the impact load F1 input from the side of the vehicle Ve can be satisfactorily supported by the floor cross member 35.

As shown in FIGS. 13 and 14, the inclined portion 107 has an upper inclined portion 108, a member front wall portion 102, and a member rear wall portion 103. The member front wall portion 102 extends from the front side of the upper inclined portion 108 to the floor panel 16. The member rear wall portion 103 extends from the rear side of the inclined portion 107 to the floor panel 16.
The inclined portion 107 is formed in a U shape by the upper inclined portion 108, the member front wall portion 102, and the member rear wall portion 103.

A gusset 62 is arranged below the floor cross member 35. The gusset 62 is erected on the inner wall 81 of the inner bulging portion 76 of the side silina 66 and the lower surface 16b of the floor panel 16. Hereinafter, the inner wall 81 of the inner bulging portion 76 will be referred to as a “side sill inner wall 81”.
The gusset 62 has a gusset inclined portion 111, a gusset front wall portion 112, a gusset rear wall portion 113, and gusset flanges 114 to 118. The gusset inclined portion 111 is formed in a rectangular shape in a plan view. The gusset inclined portion 111 extends downward from the lower surface 16b of the floor panel 16 to the inner wall 81 of the side sill toward the outside in the vehicle width direction.
The gusset front wall portion 112 extends from the front side of the gusset inclined portion 111 to the left side portion 16c of the floor panel 16. The gusset rear wall portion 113 extends from the rear side of the gusset inclined portion 111 to the left side portion 16c of the floor panel 16.

As shown in FIGS. 5 and 13, the gusset front wall portion 112 projects from the front side of the gusset inclined portion 111 toward the floor panel 16. The gusset rear wall portion 113 projects from the rear side of the gusset inclined portion 111 toward the floor panel 16. The gusset 62 is formed in a U-shaped cross section at the gusset inclined portion 111, the gusset front wall portion 112, and the gusset rear wall portion 113.
The gusset flange 114 projects from the lower side 111a of the gusset inclined portion 111. The gusset flanges 115 and 116 project from the side side 112a and the upper side 112b of the gusset front wall portion 112, respectively. The gusset flanges 117 and 118 project from the side side 113a and the upper side 113b of the gusset rear wall portion 113, respectively.

The gusset flange 114 protruding from the lower side 111a of the gusset inclined portion 111 is joined to a portion 81a of the side sill inner wall 81 facing the inner bulkhead 56.
The gusset flange 115 protruding from the side side 112a of the gusset front wall portion 112 is joined to the side sill inner wall 81. The gusset flange 117 protruding from the side side 113a of the gusset rear wall portion 113 is joined to the side sill inner wall 81.
The gusset flange 116 projecting from the upper side 112b of the gusset front wall portion 112 is joined to the lower surface 16b of the floor panel 16. The gusset flange 118 projecting from the upper side 113b of the gusset rear wall portion 113 is joined to the lower surface 16b of the floor panel 16.

In this way, the inclined portion 107 is formed on the floor cross member 35, and the upper inclined portion 108 of the inclined portion 107 is extended downward to the outer side in the vehicle width direction up to the upper portion 82 of the side sill. Further, the gusset inclined portion 111 is extended downward from the lower surface 16b of the floor panel 16 to the inner wall 81 of the side sill toward the outside in the vehicle width direction.

As shown in FIG. 14, the gusset 62 is formed in a U shape by the gusset inclined portion 111, the gusset front wall portion 112, and the gusset rear wall portion 113. In the gusset 62, the gusset flange 116 and the gusset flange 118 are joined to the floor panel 16.
Further, the inclined portion 107 of the floor cross member 35 is formed in a U shape by the upper inclined portion 108, the member front wall portion 102, and the rear wall portion member 103. In the inclined portion 107, the member front flange 104 and the member rear flange 105 are joined to the floor panel 16.
The member front flange 104 is joined to the gusset flange 116 via the left side portion 16c of the floor panel 16. The member rear flange 105 is joined to the gusset flange 118 via the left side portion 16c of the floor panel 16.
That is, the floor cross member 35 and the gusset 62 are joined with the floor panel 16 interposed therebetween.

As described above, the floor cross member 35 is formed in a U shape by the upper inclined portion 108, the member front wall portion 102, and the member rear wall portion 103. The gusset 62 is formed in a U shape by the gusset inclined portion 111, the gusset front wall portion 112, and the gusset rear wall portion 113. Further, the floor cross member 35 and the gusset 62 are joined with the left side portion 16c of the floor panel 16 interposed therebetween.
Therefore, the floor cross member 35 and the gusset 62 form a highly rigid closed cross section. As a result, the impact load F1 input from the side of the vehicle Ve can be transmitted from the left side sill 14 (see FIG. 5) to the floor cross member 35.

The first floor cross member 34 is joined to the first gusset 61 with the floor panel 16 interposed therebetween, like the floor cross member (that is, the second floor cross member) 35. Therefore, the first floor cross member 34 and the first gusset 61 form a highly rigid closed cross section. As a result, the impact load F1 input from the side of the vehicle Ve can be transmitted from the left side sill 14 (see FIG. 5) to the first floor cross member 34.

As shown in FIG. 5, the cross section S1 is formed by the inclined portion 107 and the gusset 62. Further, the straight portion 35a of the floor cross member 35 is formed in the cross section S2. The cross section S1 is formed to have substantially the same cross-sectional shape as the cross section S2.

Therefore, the strength of the inclined portion 107 is secured in the same manner as the straight portion 35a of the floor cross member 35. As a result, when the impact load F1 is input from the side of the vehicle Ve, the load F3 can be transmitted from the inner bulkhead 56 to the gusset 62 via the side sill inner wall 81. The load F3 transmitted to the gusset 62 can be transmitted to the floor cross member 35, and the load F3 can be supported by the floor cross member 35. Thereby, the battery pack 28 (that is, the battery 123) can be protected from the impact load F1.

Further, by providing the floor cross member 35 on the upper surface 16a of the floor panel 16, the floor cross member can be removed from below the floor panel 16. Therefore, the space 119 below the floor panel 16 can be increased. As a result, the capacity of the battery pack 28 provided below the floor panel 16 can be increased. As a result, the capacity of the battery 123 housed in the battery pack 28 can be increased, and the cruising range of the vehicle Ve can be increased.

Returning to FIG. 4, a battery pack 28 is provided between the left side sill 14 and the right side sill 15 (see FIG. 2) and below the floor panel 16. The battery pack 28 includes a battery case 121 and a lid 122. The battery case 121 has a case wall portion 124, a case bottom portion 125, and a case flange 126.
The case wall portion 124 has a front wall, a rear wall, a left side wall 124a, and a right side wall. The case wall portion 124 is formed in a rectangular frame shape by the front wall, the rear wall, the left side wall 124a, and the right side wall.

The lower end of the case wall 124 is closed by the case bottom 125, and an opening 127 is formed at the upper end. The case flange 126 projects from the entire circumference of the opening 127 of the case wall portion 124 to the outside of the battery case 121.
A battery cross member 131 is provided inside the battery case 121 (that is, inside the battery pack 28 129). The battery cross member 131 extends in the vehicle width direction inside 129 of the battery pack 28. The battery cross member 131 has a flange 131a at the left end. The flange 131a is joined to the left side wall 124a of the case wall portion 124.
Further, a plurality of lower mounting portions 133a of the fastening members 133 are attached to the battery cross member 131 with bolts and nuts at intervals in the vehicle width direction. The battery 123 is housed inside the battery case 121.

The opening 127 of the battery case 121 is closed by the lid 122 from above. The lid 122 has a lid wall portion 135, a lid top 136, and a lid flange 137.
The lid wall portion 135 has a front wall, a rear wall, a left side wall 135a, and a right side wall. The lid wall portion 135 is formed in a rectangular frame shape by the front wall, the rear wall, the left side wall 135a, and the right side wall. That is, the lid wall portion 135 is formed in the same manner as the case wall portion 124.
The upper end of the lid wall 135 is closed by the lid top 136, and an opening 138 is formed at the lower end. The lid flange 137 projects from the entire circumference of the opening 138 of the lid wall 135 to the outside of the lid 122.

By superimposing the lid flange 137 on the case flange 126 from above, the lid flange 137 and the case flange 126 are sealed with a sealing member. Therefore, the opening 127 of the battery case 121 is closed by the lid 122. The battery 123 is housed in the internal 129 of the battery pack 28. In a state where the opening 127 of the battery case 121 is closed by the lid 122, the upper portion 133b of the fastening member 133 projects upward from the opening 136a of the lid top 136.

The protruding upper portion 133b is fastened to the outer fastening bracket 141 of the floor cross member 35 with bolts 165 and nuts 166. Further, the protruding upper portion 133b is fastened to the inner fastening bracket 142 of the floor cross member 35 with bolts 167 and nuts 168. As a result, the battery pack 28 is connected to the outer fastening bracket 141 and the inner fastening bracket 142 of the floor cross member 35 via a plurality of fastening members 133 and the like.

As shown in FIGS. 5 and 15, the battery pack 28 is arranged inside the left side sill 14 in the vehicle width direction. The battery pack 28 is provided at a predetermined interval L1 with respect to the side sill inner wall 81.
A battery pack frame 29 is attached to the left side wall 124a (outer circumference of the battery pack 28) of the case wall portion 124. The battery pack frame 29 is formed in an L-shaped cross section. The battery pack frame 29 includes a fixing portion 143 and a frame main body 144.

The fixing portion 143 is attached to the lower portion (lower surface) 83 of the inwardly bulging portion 76. The lower portion 83 of the inwardly bulging portion 76 is a portion serving as a lower portion of the left side sill 14. Hereinafter, the lower part of the left side sill 14 is referred to as "side sill lower part 83".
The frame main body 144 is raised from the fixing portion 143 toward the side sill inner wall 81, and is arranged so as to face the inner bulkhead 56 via the side sill inner wall 81.

The frame body 144 has an inner wall portion 146, an outer wall portion 147, a top portion 148, a bottom portion 149, and a lower flange 151. The frame main body 144 is formed in a rectangular frame shape with an inner wall portion 146, an outer wall portion 147, a top portion 148, and a bottom portion 149.
The inner wall portion 146 of the frame body 144 is joined along the left side wall 124a of the case wall portion 124. Further, the inner wall portion 146 is also joined to the flange 131a of the battery cross member 131 via the left side wall 124a. That is, the frame body 144 is joined to the battery cross member 131.
The lower flange 151 is joined along the case bottom 125 of the battery case 121. The bulkhead 152 is attached to the inside of the frame body 144.

The fixing portion 143 has a top portion 154, an outer wall portion 155, a bottom portion 156, a bent portion 157, an upper flange 158, and a lower flange 159. The fixing portion 143 is formed in a U-shaped cross section at the top portion 154, the outer wall portion 155, and the bottom portion 156. The upper flange 158 is joined along the outer wall portion 147 of the frame main body 144. The lower flange 159 is joined along the lower flange 151 of the frame body 144.
A collar 162 is interposed inside 161 of the fixing portion 143, and a bolt 163 is penetrated through the collar 162. A fixing portion 143 is attached to the lower side sill 83 by a bolt 163 and a nut 164.

In this way, the fixing portion 143 is attached to the lower side sill 83, and the frame body 144 of the battery pack frame 29 is raised toward the side sill inner wall 81. In the frame body 144, the frame body 144 faces the inner bulkhead 56 via the side sill inner wall 81. Further, the frame body 144 is joined to the flange 131a of the battery cross member 131.

Therefore, when the impact load F1 is input from the side of the vehicle Ve, the load F4 is transmitted from the left side sill 14 to the battery cross member 131 via the fixing portion 143 and the frame body 144, and the battery cross member 131 supports the load F4. be able to. Further, the impact load F1 input from the side of the vehicle Ve can be transmitted from the inner bulkhead 56 to the frame main body 144 and the battery cross member 131 via the side sill inner wall 81, and the battery cross member 131 can support the load F5. it can.

As a result, the outer bulkhead 52 and the inner bulkhead 56 can be sufficiently crushed by the impact load F1 to satisfactorily absorb the impact energy, and the battery 123 housed in the inner 129 of the battery pack 28 can be protected from the impact load F1.
Further, by supporting the load F4 and the load F5 with the battery cross member 131, the fixed portion 143 and the frame main body 144 (that is, the battery pack frame 29) can be crushed. As a result, the impact energy can be absorbed more satisfactorily, and the battery 123 can be protected from the impact load F1.

Next, an example in which the battery 123 is protected by the vehicle body lower structure 12 when the impact load F6 is input from the side of the vehicle Ve will be described with reference to FIG.
As shown in FIG. 16, the impact load F6 is input to the left side sill 14 from the side of the vehicle Ve. The impact load F6 input to the left side sill 14 deforms the outer bulging portion 71 of the side sill outer 65 of the left side sill 14 inward in the vehicle width direction. The outer bulging portion 71 is deformed and comes into contact with the bottom portion 85 of the outer bulkhead 52.

The joining flanges 86 and 93 of the outer bulkhead 52 and the inner bulkhead 56 are joined to each other via a stiffener 67. Therefore, the box-shaped shape of the outer bulkhead 52 is constrained by the joint flange 86. Further, the box shape of the inner bulkhead 56 is restrained by the joint flange 93.
As a result, the impact load F6 is transmitted to the entire area (that is, the entire circumference) of the side wall 84 of the outer bulkhead 52 by contacting the outer bulging portion 71 with the bottom 85 of the outer bulkhead 52. Further, the impact load F6 is transmitted to the entire area (that is, the entire circumference) of the side wall 91 of the inner bulkhead 56.
Due to the impact load F6, the entire circumference of the side wall 84 of the outer bulkhead 52 and the entire circumference of the side wall 91 of the inner bulkhead 56 are crushed by buckling under the impact load F6 to absorb impact energy.

The remaining load absorbed by the outer bulkhead 52 and the inner bulkhead 56 is transmitted to the floor cross member 35 as the load F7 via the gusset 62 and the inclined portion 107. Further, the remaining load is transmitted to the battery cross member 131 as a load F8 via the fixing portion 143 and the frame main body 144. Further, the remaining load is transmitted to the battery cross member 131 as a load F9 via the frame body 144.

The load F7 is supported by the floor cross member 35. Further, the load F8 and the load F9 are supported by the battery cross member 131. Therefore, the outer bulkhead 52 and the inner bulkhead 56 can be sufficiently crushed, and the impact energy due to the impact load F6 can be satisfactorily absorbed by the outer bulkhead 52 and the inner bulkhead 56.
Further, by supporting the load F8 and the load F9 with the battery cross member 131, the fixed portion 143 and the frame main body 144 (that is, the battery pack frame 29) can be crushed. Therefore, the load F8 and the load F9 can be satisfactorily absorbed by the battery pack frame 29.
As a result, the battery 123 housed in the internal 129 of the battery pack 28 can be protected from the impact load F6.

The technical scope of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, in the above embodiment, the battery pack 28 is exemplified as an underfloor mounting component (that is, an in-vehicle component), but the present invention is not limited to this. As another example, a fuel tank, a fuel cell stack, or the like can be used as an underfloor mounting component.

Ve …… Vehicle 10 …… Body 10a… Left side (one of both sides of the vehicle)
10b ... Right side (the other on both sides of the vehicle)
12 …… Body lower structure 14, 15… Left and right side sill (side sill)
16 ... Floor panel 16a ... Upper surface of floor panel 16b ... Lower surface of floor panel 28 ... Battery pack (underfloor mounting parts)
31 …… Driver seat (seat)
32 …… Passenger sheet (sheet)
34-36 ... 1st to 3rd floor cross members (floor cross members)
51-53 ... First to third outer bulkheads (bulkheads)
55-57 ... First to third inner bulkhead (bulkhead)
61-63
… First to third gussets (gussets)
81 …… Side sill inner wall (side sill inner wall)
81a ... Part facing the bulkhead 82 ... Upper side sill (upper side sill)
88 …… Outside space (inside the side sill)
89 …… Inner space (inside the side sill)
101 ... member upper part 102 ... member front wall part 103 ... member rear wall part 107 ... inclined part 108 ... upper inclined part 111 ... gusset inclined part 112 ... gusset front wall part 113 ... gusset rear wall part 141 ... outer fastening bracket (fastening bracket) )
142 ... Inner fastening bracket (fastening bracket)
171, 301 ... End member 172, 302 ... Straight line member 173, 303 ... Central member 177 ... Joint seat 178 ... Bead 184 ... First joint 196 ... Second joint

Claims (5)

In a vehicle body substructure with floor panels placed between the side sills on both sides of the vehicle and erected above each side sill
A floor cross member provided on the upper surface of the floor panel, extending in the vehicle width direction, erected between the side sills, and having a member upper portion located above the upper portion of the side sills.
A gusset which is arranged below the floor cross member, is erected on the inner wall of the side sill and the lower surface of the floor panel, and extends downward from the lower surface to the inner wall in the vehicle width direction is provided.
The member top, have a top inclined portion extending downward slope toward the outside in the vehicle width direction to the top of the side sill,
The floor cross member
It has an end member, a straight part member, and a center part member that are joined in order from the outside to the center in the vehicle width direction.
An underfloor mounting component arranged below the floor panel is connected to the first joint portion between the end member and the straight portion member and the second joint portion between the straight portion member and the central portion member. Joined to the fastening bracket,
The lower part of the car body is characterized by this. The floor cross member
A joint seat portion that extends outward in the vehicle width direction from the upward inclined portion and is joined to the upper portion of the side sill.
It has a bead that extends in the vehicle width direction from the upper inclined portion to the joint seat portion and rises upward.
The vehicle body lower structure according to claim 1. The floor cross member
The upper inclined portion, the member front wall portion extending from the front side of the upper inclined portion to the floor panel, and the member rear wall portion extending from the rear side of the upper inclined portion to the floor panel are formed in a U shape.
The gusset
The gusset inclined portion extending downward from the lower surface to the inner wall in the vehicle width direction, the gusset front wall portion extending from the front side of the gusset inclined portion to the floor panel, and the rear side of the gusset inclined portion described above. Formed in a U shape on the rear wall of the gusset that extends to the floor panel
The floor cross member and the gusset are joined with the floor panel interposed therebetween.
The vehicle body lower structure according to claim 1 or 2, characterized in that. A bulkhead provided inside the side sill and facing the inner wall is provided.
The gusset is attached to a portion of the inner wall facing the bulkhead.
The vehicle body lower structure according to any one of claims 1 to 3, wherein the vehicle body lower structure is characterized. At least a pair of the floor cross members are provided at intervals in the front-rear direction of the vehicle body.
Seats are attached to a pair of floor cross members,
The vehicle body lower structure according to any one of claims 1 to 4, characterized in that.

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