WO2018212161A1

WO2018212161A1 - Vehicle body lower structure

Info

Publication number: WO2018212161A1
Application number: PCT/JP2018/018702
Authority: WO
Inventors: 貴志新田; 誉山田; 貫志金子; 仁齊藤; 龍篠田; 栄治小池; 壮吾今村; 匠露崎
Original assignee: 本田技研工業株式会社
Priority date: 2017-05-18
Filing date: 2018-05-15
Publication date: 2018-11-22
Also published as: CN110650886B; CN110650886A

Abstract

A vehicle body lower structure (12) includes a floor panel (16) disposed between side sills (14, 15) on both sides of a vehicle (Ve) and provided to link upper parts (82) of the side sills (14, 15). The vehicle lower body structure comprises: floor cross members (34, 35, 36) provided on a top surface (16a) of the floor panel (16), extending in the vehicle width direction, provided to link the side sills (14, 15), and including a member upper part (101) positioned above the upper part (82) of the side sills (14, 15); and gussets (61, 62, 63) disposed below the floor cross members (34, 35, 36), provided to link an inner wall (81) of the side sills (14, 15) and a bottom surface (16b) of the floor panel (16), and extending in a downward gradient toward the outside in the vehicle width direction from the bottom surface (16b) of the floor panel (16) to the inner wall (81) of the side sills (14, 15). The member upper part (101) includes an upper inclined part (108) that extends in a downward gradient toward the outside in the vehicle width direction to the upper part (82) of the side sills (14, 15). DRAWING: FIG. 5: AA UP

Description

Underbody structure

The present invention relates to an underbody structure of a vehicle body.
The present application is related to Japanese Patent Application No. 2017-098925, filed on May 18, 2017, Japanese Patent Application No. 2017-099051, filed on May 18, 2017, and May 19, 2017 The priority is claimed based on Japanese Patent Application No. 2017-100125 filed in Japan, the contents of which are incorporated herein by reference.

As a lower body structure, for example, a floor panel is constructed between a side sill on the left side and a side sill on the right side, and a battery pack (under-floor mounting component) is mounted below the floor panel.
A battery is housed inside the battery pack. The battery in the battery pack needs to be protected from the load input from the side of the vehicle. For this reason, the energy absorption member is provided inside the side sill by increasing the height of the side sill. By absorbing the impact load inputted from the side of the vehicle by the energy absorbing member, it becomes possible to protect the battery (that is, the under-floor mounted component) in the battery pack from the impact load (for example, see Patent Document 1) .
In addition, a battery cross member is provided inside the battery pack.
The battery cross member is fastened to the lower portion of the floor cross member by bolts and nuts. The floor cross member is attached to the floor panel. The rigidity of the vehicle body is enhanced by fastening the battery cross member to the floor cross member (see, for example, Patent Document 2).
For example, in the technology described in Patent Document 2, a nut is fixed to the cross member of the floor panel, a sleeve is fixed to the cross member of the battery pack, the battery pack is set under the floor panel, and the sleeve is positioned on the nut After that, the cross-member of the floor panel and the cross-member of the battery pack are fastened by tightening the bolt inserted into the sleeve into the nut, thereby enhancing the rigidity of the vehicle body.

U.S. Pat. No. 8,702,161 U.S. Patent No. 8336658

However, in the underbody structure of Patent Document 1, the height of the side sill is increased. Thus, the top of the side sill is located above the floor panel. For this reason, when a passenger gets on and off, the side sill becomes a hindrance, and it is difficult to ensure good getting on and off the passenger.
Further, it is conceivable that a seat can be attached to the floor cross member in the lower body structure. The seat is provided with a tongue support (belt support). That is, the belt support portion is connected to the floor cross member via the sheet. Since the tongue of the seat belt is supported by the belt support portion, the occupant is restrained by the seat belt. In this state, for example, when an impact load is input from the front of the vehicle, a tensile load acts on the belt support portion via the seat belt.
Therefore, it is necessary to firmly support the belt support portion by the floor cross member. As a measure against this, it is conceivable to increase the rigidity of the floor cross member. However, if it is attempted to increase the rigidity of the floor cross member more than necessary, that hinders the reduction of the weight of the floor cross member (that is, the weight of the vehicle body), and there is room for improvement from this point of view.
Further, in the above-mentioned prior art, when the battery pack is set under the floor panel, the sleeve needs to be accurately aligned with the center of the nut, so that there is a problem that the assembling workability is poor.

Therefore, it is an object of the present invention to provide an underbody structure capable of protecting an under-floor mounted component from an impact load input from the side of a vehicle in a state where a passenger's get-on / off property is properly secured.
Another object of the present invention is to provide an underbody structure capable of supporting a belt support without increasing the rigidity of the floor cross member more than necessary.
Another object of the present invention is to provide a vehicle body lower structure capable of enhancing assembling workability when fastening a cross member of an under-floor mounting component to a cross member of a floor panel.

As means for solving the above problems, an aspect of the present invention has the following configuration.
(1) A vehicle body lower structure according to an aspect of the present invention is disposed on the upper surface of the floor panel in a vehicle body lower structure provided with a floor panel that is disposed between the side sills of both sides of the vehicle and is constructed over the top of each side sill. A floor cross member having a member upper portion which is provided, extends in the vehicle width direction, is installed between the side sills, and is located above the upper portion of the side sill, and is disposed below the floor cross member and is an inner wall of the side sill And a gusset extended on the lower surface of the floor panel and extending downward from the lower surface of the floor panel to the inner wall of the side sill in the vehicle width direction, and the upper part of the member extends to the upper part of the side sill It has an upper slope portion extending downward to the outside in the vehicle width direction.

According to the vehicle body lower structure described in the above (1) of the present invention, the upper portion of the side sill and the upper surface of the floor panel can be made the same height by erecting the floor panel on the upper portion of the side sill. As a result, the side sill does not get in the way when getting in and out of the occupant, and it is possible to ensure good getting in and out of the occupant.

Further, an upper inclined portion is provided at the upper portion of the floor cross member, and the upper inclined portion is extended downward toward the upper side of the side sill in the vehicle width direction. Further, the gusset was extended downward in the vehicle width direction from the lower surface of the floor panel to the inner wall of the side sill. Therefore, it is possible to form the cross section substantially the same as the cross section of the floor cross member by the upper inclined portion and the gusset. In addition, 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.
Thus, when an impact load is input from the side of the vehicle, the load can be transmitted from the inner bulkhead to the gusset through the inner wall of the side sill. By transmitting the load transmitted to the gusset to the floor cross member and supporting the load by the floor cross member, it is possible to protect the underfloor mounted component from the impact load input from the side of the vehicle.

Furthermore, by providing the floor cross member on the upper surface of the floor panel, the floor cross member can be removed from the lower side of the floor panel. As a result, the capacity of an underfloor mounting component such as a battery pack provided below the floor panel can be increased.

(2) In the vehicle body lower structure described in the above (1), an underfloor cross member disposed below the floor cross member and attached to an under floor mounting component, and a fastening unit for attaching the under floor cross member to the floor cross member And a sheet attached to the floor cross member, wherein the sheet is attached in the vicinity of the fastening unit of the floor cross member to transmit a load to the fastening unit. And a belt support unit connected to the seat attachment unit and supporting a seat belt.

According to the vehicle body lower structure described in (2) of the present invention, the floor cross member is reinforced by the under floor cross member by attaching the under floor cross member to the floor cross member by the fastening unit. Thereby, the rigidity of the vehicle body can be enhanced.
By the way, the belt support portion is connected to the sheet attachment portion. Thus, for example, when an impact load is input from the front of the vehicle, a tensile load is applied to the belt support through the seat belt.

Therefore, the sheet attachment portion is attached to the floor cross member in the vicinity of the fastening unit. Therefore, the tensile load acting on the belt support portion can be transmitted to the fastening unit through the sheet mounting portion, and the tensile load can be supported by the fastening unit. That is, the occupant can be suitably restrained by the seat belt.
Thus, the tensile load acting on the belt support can be supported using the fastening unit. Thus, the belt support can be supported without increasing the rigidity of the floor cross member more than necessary.

(3) In the vehicle body lower structure according to (2), a stud bolt provided on one of the floor cross member and the second cross member and protruding to the other side, and the floor cross member and the second cross member Attached to a bolt insertion portion provided on the other side and forming a bolt insertion hole having a diameter larger than the diameter of the stud bolt, and attached to the stud bolt penetrating the bolt insertion hole, in cooperation with the stud bolt It may further comprise a nut for fastening the floor cross member and the second cross member.

According to the vehicle body lower structure described in the above (3) of the present invention, the vehicle body rigidity can be enhanced by fastening the floor cross member and the second cross member of the under-floor mounting component. Since the diameter of the bolt insertion hole is set larger than the diameter of the stud bolt, the assembly work of the under-floor mounted component can be easily performed even if an assembly error (a tolerance) or the like occurs. By using the stud bolt as the fastening member, the stud bolt can be inserted into the bolt insertion hole simultaneously with the work of setting the under-floor mounting component in a fixed position under the floor panel. Since the bolt insertion hole has a diameter larger than that of the stud bolt, the stud bolt can be inserted into the bolt insertion hole after absorbing an error such as positional deviation of the stud bolt and the bolt insertion hole.

(4) In the vehicle body lower structure described in the above (1), the floor cross member extends from the upper inclined portion toward the outer side in the vehicle width direction, and a joint seat joined to an upper portion of the side sill; And a bead extending in the vehicle width direction from the upper inclined portion to the joint seat and protruding upward.

According to the vehicle body lower structure described in the above (4) of the present invention, the upper inclined portion extends downward to the upper portion of the side sill. Further, the joint seat extends from the upper inclined portion toward the outer side in the vehicle width direction. The boundary between the upper inclined portion and the joint seat is bent to form a bent portion extending in the longitudinal direction of the vehicle body.
Therefore, the bead was extended in the vehicle width direction from the upper inclined portion to the joint seat. Thus, the bead can be extended to intersect (specifically, orthogonally) the bend. Thus, the bent portion can be reinforced by the bead against the impact load input from the side of the vehicle to the joint portion.
That is, when an impact load is input to the joint seat from the side of the vehicle, the bending of the bent portion can be suppressed by the bead. Thereby, the impact load can be transmitted from the joint seat portion to the upper inclined portion through the bead, and load transfer can be prevented from being impaired.

(5) In the vehicle body lower structure described in the above (1) or (4), the floor cross member includes the upper inclined portion, a member front wall extending from the front side of the upper inclined portion to the floor panel, and The member rear wall extending from the rear side of the upper inclined portion to the floor panel is formed in a U shape, and the gusset slopes outward toward the outer side in the vehicle width direction from the lower surface of the floor panel to the inner wall of the side sill It is formed in a U-shape with an extending gusset inclined portion, a gusset front wall extending from the front side of the gusset inclined portion to the floor panel, and a gusset rear wall extending from the rear end of the front gusset inclined portion to the floor panel The floor cross member and the gusset may be joined with the floor panel interposed.

According to the vehicle body lower structure described in the above (5) of the present invention, the floor cross member is formed in a U shape by the upper inclined portion, the front wall and the rear wall. The gusset is formed in a U-shape with the gusset inclined portion, the gusset front wall and the gusset rear wall. Also, the floor cross member and the gusset are joined with the floor panel interposed.
Therefore, a rigid closed cross section is formed by the floor cross member and the gusset. Thereby, the impact load inputted from the side of the vehicle can be transmitted from the side sill to the floor cross member.

(6) In the vehicle body lower structure according to any one of (1), (4), and (5), a bulkhead provided inside the side sill and facing the inner wall of the side sill is further provided. The gusset may be attached to a portion of the inner wall of the side sill facing the bulkhead.

According to the vehicle body lower structure described in the above (6) of the present invention, the bulkhead in the side sill is opposed to the inner wall of the side sill. In addition, a gusset is attached 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 through the bulkhead. Thereby, the impact load inputted from the side of the vehicle can be transmitted to the floor cross member through the gusset and supported by the floor cross member. As a result, the under-floor mounted component can be protected from the impact load input from the side of the vehicle.

(7) In the vehicle body lower structure according to any one of (1), (4), (5) and (6), at least one pair of floor cross members are provided at intervals in the vehicle longitudinal direction. The seat may be attached to the pair of floor cross members.

According to the vehicle body lower structure described in the above (7) of the present invention, the seat is attached to the pair of floor cross members. The pair of floor cross members are bridged to 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 suppress the deformation of the vehicle body side portion such as the side sill to the seat, and protect the occupant from the impact load in addition to the underfloor mounting component.

(8) In the vehicle body lower structure according to any one of (1), (4), (5), (6), and (7), the floor cross member moves from the outer side to the center in the vehicle width direction. An end member, a linear portion member, and a central portion member, which are sequentially joined in a direction toward the first member; a first joint portion between the end member and the linear portion member; a first portion between the linear portion member and the central portion member The two joints may be joined to a fastening bracket to which the below-the-floor mounting component disposed below the floor panel is connected.

According to the vehicle body lower structure described in the above (8) of the present invention, the end member of the floor cross member is joined to the side sill. Also, a central member of the floor cross member is formed, for example, in accordance with the floor tunnel. For this reason, the end member and the central member have a relatively complicated shape. On the other hand, the straight portion member can be suppressed to a relatively simple shape.
The floor cross member is divided into three members: an end member, a straight portion member, and a central portion member. Therefore, for example, end members and central members of complicated shapes can be draw-formed (drawn), and linear members of simple shapes can be bend-formed (bent). As described above, by bending the straight portion members, the manufacturing cost of the floor cross member can be reduced.

In addition, it is possible to optimize the collision mode by making the strengths of the end member, the straight portion member, and the center member different. In this case, a device for securing the strength of the first joint between the end member and the straight line member, and the second joint between the straight line member and the central part member is required. Then, it decided to join a fastening bracket to the 1st joined part and the 2nd joined part. Fastening brackets use high strength members to support underfloor mounting components.
Thereby, by joining a fastening bracket to a 1st junction part or a 2nd junction part, a 1st junction part or a 2nd junction part can be reinforced with a fastening bracket, and load transmission performance of a floor cross member can be secured. .

(9) In the vehicle body lower structure described in (2), the fastening unit includes a fastening bracket provided on the floor cross member, and a fastening member for fastening the underfloor cross member to the fastening bracket, The fastening bracket is disposed along the floor panel, and a bottom portion fastened to the fastening member, a bulkhead portion raised from the bottom portion, and an upper end of the bulkhead portion along the floor cross member It may have an upper flange which can transmit said load to said fastening seat part by being fixed near the fastening seat part which said sheet attaching part was fastened among said floor cross members. .

According to the vehicle body lower structure described in (9) of the present invention, the bottom portion of the fastening bracket is fastened to the fastening member. Further, the upper flange of the fastening bracket is fixed to the floor cross member in the vicinity of the fastening seat. Further, the seat mounting portion is fastened to the fastening seat.
Therefore, when an impact load is input from the front of the vehicle, a tensile load acting on the seat mounting portion can be transmitted from the fastening seat portion of the floor cross member to the underfloor cross member through the fastening bracket and the fastening member. Thus, the tensile load acting on the seat belt can be supported by the floor cross member and the under floor cross member.
Thus, by supporting the tensile load acting on the seat belt with the cross members of the two members, it is possible to support the belt support without increasing the rigidity of the floor cross member more than necessary.

(10) In the vehicle body lower structure described in the above (9), the floor cross member includes an end member, a linear portion member, and a central portion member joined in order from the outer side to the center in the vehicle width direction The first joint portion between the end member and the linear portion member, and the second joint portion between the linear portion member and the central portion member are connected to the under-floor mounted components disposed below the floor panel. It may be joined to the fastening bracket.

According to the vehicle body lower structure described in (10) of the present invention, the end member of the floor cross member is joined to the side sill. Also, a central member of the floor cross member is formed, for example, in accordance with the floor tunnel. For this reason, the end member and the central member have a relatively complicated shape. On the other hand, the straight portion member can be suppressed to a relatively simple shape.
The floor cross member is divided into three members: an end member, a straight portion member, and a central portion member. Therefore, for example, end members and central members of complicated shapes can be draw-formed (drawn), and linear members of simple shapes can be bend-formed (bent). As described above, by bending the straight portion members, the manufacturing cost of the floor cross member can be reduced.

In addition, it is possible to optimize the collision mode by making the strengths of the end member, the straight portion member, and the center member different. In this case, a device for securing the strength of the first joint between the end member and the straight line member, and the second joint between the straight line member and the central part member is required. Then, it decided to join a fastening bracket to the 1st joined part and the 2nd joined part. Fastening brackets use high-strength members to support underfloor mounting components (ie, in-vehicle components).
Thereby, by joining a fastening bracket to a 1st junction part or a 2nd junction part, a 1st junction part or a 2nd junction part can be reinforced with a fastening bracket, and load transmission performance of a floor cross member can be secured. .

(11) In the vehicle body lower structure described in (10), the fastening seat portion of the floor cross member is formed on the central portion member, and the upper flange is formed by the central portion member and the linear portion member. It may be pinched.

According to the vehicle body lower structure described in (11) of the present invention, the upper flange of the fastening bracket is sandwiched between the central portion member and the linear portion member. Thus, the upper flange of the fastening bracket is firmly supported between the central member and the straight member.
In addition, a fastening seat portion of the floor cross member is formed in the central portion member. The belt support portion is connected to the fastening seat portion via the sheet attachment portion. Therefore, when a tensile load is applied to the belt support portion, the tensile load can be reliably transmitted from the upper flange to the underfloor cross member through the fastening bracket. As a result, the tensile load can be reliably supported by the floor cross member and the under floor cross member, and the support strength of the belt support (that is, the seat belt) can be secured.

(12) In the vehicle body lower structure according to any one of the above (9) to (11), the fastening seat portion is formed on the vehicle width direction center side and the vehicle width direction end side of the floor cross member. The seat attachment portion includes a pair of seat support portions provided at intervals in the vehicle width direction, and one of the pair of seat support portions reinforces the fastening member on the center side in the vehicle width direction. Is attached near the fastening member on the center side, and the other of the pair of seat support portions is near the fastening member on the end side so as to reinforce the fastening member on the end side in the vehicle width direction. It may be attached.

According to the vehicle body lower structure described in the above (12) of the present invention, the fastening seat portion is formed on the vehicle width direction center side and the vehicle width direction end side of the floor cross member. In addition, one seat support portion is attached near the central-side fastening seat portion so as to reinforce the central-side fastening seat portion in the vehicle width direction. Furthermore, the other seat support portion is attached in the vicinity of the end-side fastening seat so as to reinforce the fastening seat on the end side in the vehicle width direction. The rigidity of the floor cross member is sufficiently ensured by the pair of seat support portions.
Therefore, when a tensile load is applied to the belt supporting portion, the tensile load can be supported more reliably by the floor cross member and the under floor cross member, and the supporting strength of the belt supporting portion (that is, the seat belt) is further enhanced. It can be secured well.

(13) In the lower vehicle body structure described in (12), the seat support portion is a seat rail extending in the longitudinal direction of the vehicle body so as to slide the seat in the longitudinal direction of the vehicle body, and the floor cross member is The seat rails may be attached to at least the fastening seat portions of the pair of floor cross members, which are disposed at least in the longitudinal direction of the vehicle body.

According to the lower vehicle body structure described in the above (13) of the present invention, the seat supporting portion is a seat rail extending in the vehicle longitudinal direction. A seat rail is attached to a fastening seat portion of a pair of floor cross members arranged in the longitudinal direction of the vehicle body. Therefore, the rigidity of the floor cross member is sufficiently ensured by the seat rail. As a result, when a tensile load is applied to the belt support portion, the tensile load can be more reliably supported by the floor cross member and the under floor cross member. That is, the support strength of the belt support portion (i.e., the seat belt) can be further secured.
Further, by attaching the seat rail to the fastening seat of the pair of floor cross members, the fastening bracket in the vicinity of the fastening seat can be reinforced by the seat rail. Thus, the rigidity of the fastening bracket is enhanced. As a result, the under-floor mounting component can be held securely, and the holding strength of the under-floor mounting component can be further secured.

(14) In the vehicle body lower structure described in the above (3), the floor cross member includes an end member, a linear portion member, and a central portion member joined in order from the outer side to the center in the vehicle width direction The first joint between the end member and the linear member and the second joint between the linear member and the central member may be joined to a fastening bracket to which the underfloor mounting component is coupled.

According to the vehicle body lower part structure described in the above (14) of the present invention, the floor cross member is divided into three members of the end member, the straight portion member and the central portion member, and for example, the end member of the complicated shape or the center It is possible to switch the manufacturing method, such as draw-forming part members and bend-forming a simple-shaped straight part member, thereby reducing the manufacturing cost of the floor cross member.
In addition, it is possible to optimize the collision mode by making the strengths of the end member, the straight portion member, and the center member different. In this case, there is a need for a device for securing the strength of the first joint between the end member and the linear portion member, and the second joint between the linear portion member and the central portion member, but the first joint and the second joint are required. By joining the fastening bracket to the part, the first joint portion and the second joint portion can be reinforced by the fastening bracket, and the load transfer performance of the floor cross member can be secured.

(15) In the vehicle body lower structure described in (3) or (14), the nut integrally forms a flange having a diameter larger than that of the bolt insertion hole, and the nut is formed on the floor cross member or the second cross member. It may be attached to the stud bolt through the formed working hole.

According to the lower part structure of the vehicle body described in the above (15) of the present invention, a flange having a diameter larger than that of the bolt insertion hole is provided on the nut. The members can be securely fastened. Since the nut is integrally formed with the flange, the operation for attaching to the stud bolt through the working hole can be easily performed.

(16) In the lower part of the vehicle body described in (14), the fastening bracket has a plate shape along the floor panel, and a bottom portion in which the bolt insertion hole is formed, and an end of the bottom portion in the first direction. A lower flange extending continuously in a first direction from the lower part, and a bulkhead bent at an end in a second direction crossing the first direction of the bottom and extending toward the top of the floor cross member And an upper flange bent and extended along the upper portion of the floor cross member from the tip of the bulkhead portion, the upper flange being fixed to the upper portion of the floor cross member, and the lower flange being , May be fixed to the floor panel.

According to the lower part structure of the vehicle body described in (16) of the present invention, since the upper portion of the floor cross member and the floor panel are connected by the bulkhead portion of the fastening bracket, the strength and rigidity of the floor cross member can be improved. it can. The bonding strength between the fastening portion around the bolt insertion hole and the upper portion of the floor cross member can be improved by the upper and lower flanges, and the fastening portion can be effectively reinforced.

(17) In the lower part of the vehicle body described in (16), the upper flange has a thickness direction between upper surface portions of adjacent members in the vehicle width direction in at least one of the first joint portion and the second joint portion. May be held between the two.

According to the vehicle body lower structure described in the above (17) of the present invention, since the first joint portion and the second joint portion are joined via the upper flange of the fastening bracket fastened to the under-floor mounting component, Bonding strength with the floor cross member can be improved.

(18) In the vehicle body lower structure according to any one of (3), (14), (15), (16) and (17), the underfloor mounting component is waterproofed between the underfloor mounting component and the floor panel. A cover is provided, a through hole for inserting the stud bolt is formed in the waterproof cover, a sealing member for sealing the periphery of the stud bolt in a watertight manner is attached to the through hole, and the sealing member is It may be inserted in a compressed state between the floor panel and the waterproof cover.

According to the lower part of the vehicle body structure described in the above (18) of the present invention, it is possible to suppress the water intrusion from the through hole through which the stud bolt is inserted in the waterproof cover of the underfloor mounting part by the seal member. The sealing member is sandwiched between the floor panel and the waterproof cover in a compressed state, so that it is possible to obtain an anti-vibration and soundproof effect of the floor panel and the waterproof cover.

(19) In the vehicle body lower structure according to any one of (3), (14), (15), (16), (17), and (18), the bolt insertion hole may be formed in the floor panel. And a drainage groove extending from the floor through hole to the outside of the under-floor mounting component in a plan view.

According to the vehicle body lower structure described in the above (19) of the present invention, even if water intrudes into the vehicle compartment from the floor through hole, this water can be drained from the drainage groove to the outside of the under-floor mounted component.

(20) The vehicle body lower structure according to any one of the above (3), (14), (15), (16), (17), (18) and (19) is the vehicle width of the floor panel The underfloor mounting component may further comprise a mounting component frame supported by the lower surface of the side sill, and the second cross member may be fixed to the mounting component frame. .

According to the vehicle body lower structure described in the above (20) of the present invention, in the underfloor mounting component, the second cross member is fixed to the mounting component frame supported by the side sill of the vehicle body. Can be firmly supported.

According to the aspect of the present invention, by laying the floor panel on the upper portion of the side sill, the upper portion of the side sill and the upper surface of the floor panel can be at the same height. As a result, the side sill does not get in the way when getting in and out of the occupant, and it is possible to ensure good getting in and out of the occupant.
Furthermore, the upper slope of the floor cross member is extended to the upper side of the side sill, and the gusset is extended from the lower surface of the floor panel to the inner wall of the side sill. As a result, the under-floor mounted component can be protected from the impact load input from the side of the vehicle.
Further, the sheet attachment portion is attached in the vicinity of the fastening unit so that the load can be transmitted to the fastening unit among the floor cross members. Thus, the belt support can be supported without increasing the rigidity of the floor cross member more than necessary.

FIG. 1 is a perspective view showing a lower vehicle body structure according to a first embodiment of the present invention. It is a top view which shows the vehicle body lower part structure in 1st embodiment of this invention. It is a perspective view which shows the state which removed the sheet | seat from the vehicle body lower structure in 1st embodiment of this invention. FIG. 4 is a cross-sectional view showing a state in which the vehicle body lower structure according to the first embodiment of the present invention is broken along the line IV-IV in FIG. 2; FIG. 5 is a cross-sectional view showing an enlarged portion V of FIG. 4 in the vehicle body lower structure according to the first embodiment of the present invention. FIG. 1 is a perspective view showing an outer bulkhead and an inner bulkhead of a vehicle body lower structure according to a first embodiment of the present invention. FIG. 2 is an exploded perspective view showing an outer bulkhead and an inner bulkhead of the lower vehicle body structure in the first embodiment of the present invention. FIG. 3 is a perspective view showing a first floor cross member and a second floor cross member of the vehicle body lower structure according to the first embodiment of the present invention. FIG. 3 is an exploded perspective view showing a first floor cross member and a second floor cross member of the vehicle body lower structure according to the first embodiment of the present invention. FIG. 10 is a perspective view showing an enlarged portion X of FIG. 9 in the vehicle body lower structure according to the first embodiment of the present invention. FIG. 5 is a cross-sectional view showing an enlargement of a portion XI of FIG. 4 in the vehicle body lower structure according to the first embodiment of the present invention. It is sectional drawing which shows the expansion of the XII part of FIG. 4 in the vehicle body lower part structure in 1st embodiment of this invention. It is a perspective view showing gusset of the underbody structure of a first embodiment of the present invention. FIG. 9 is a perspective view showing a broken state along line XIXI-XIIII of FIG. 8 in the lower vehicle body structure in the first embodiment of the present invention. It is a perspective view showing the state where the battery pack frame of the underbody structure of a car body in a first embodiment of the present invention was broken. It is a sectional view explaining an example which protects a battery from an impact load inputted from the side of a vehicle by underbody structure of a first embodiment of the present invention. It is a perspective view which shows the vehicle body lower part structure in 2nd embodiment of this invention. It is a top view which shows the vehicle body lower part structure in 2nd embodiment of this invention. FIG. 18 is a perspective view showing a state in which a vehicle body lower structure according to a second embodiment of the present invention is broken along the line III-III in FIG. 17; FIG. 18 is a perspective view showing a state in which a vehicle body lower structure according to a second embodiment of the present invention is broken along the line IV-IV in FIG. 17; FIG. 19 is a cross-sectional view showing a state in which the vehicle body lower structure according to the second embodiment of the present invention is broken along the line VV in FIG. 18; It is a perspective view which shows the 1st floor cross member of the vehicle body lower structure in 2nd embodiment of this invention, and a 2nd floor cross member. FIG. 7 is an exploded perspective view showing a first floor cross member and a second floor cross member of a vehicle body lower structure according to a second embodiment of the present invention. FIG. 24 is an enlarged perspective view of a portion IIX in FIG. 23 in the vehicle body lower structure according to the second embodiment of the present invention. FIG. 22 is a cross-sectional view showing an enlargement of a portion IX in FIG. 21 in the vehicle body lower structure in the second embodiment of the present invention. FIG. 22 is a cross-sectional view showing an enlarged portion X of FIG. 21 in the vehicle body lower structure according to the second embodiment of the present invention. It is a perspective view explaining the example which supports a tongue support part, when an impact load is inputted from the vehicles front in a vehicle body lower part structure in a second embodiment of the present invention. It is a perspective view which shows the vehicle body lower part structure in 3rd embodiment of this invention. It is a top view which shows the vehicle body lower part structure in 3rd embodiment of this invention. It is a perspective view which shows the state which removed the sheet | seat from the vehicle body lower part structure in 3rd embodiment of this invention. FIG. 30 is a cross-sectional view showing a state in which the vehicle body lower structure according to the third embodiment of the present invention is broken along the line IV-IV in FIG. 29. FIG. 32 is a cross-sectional view showing an enlarged portion V of FIG. 31 in the lower vehicle body structure in the third embodiment of the present invention. FIG. 14 is a perspective view showing an outer bulkhead and an inner bulkhead of a lower vehicle body structure according to a third embodiment of the present invention. FIG. 14 is an exploded perspective view showing an outer bulkhead and an inner bulkhead of a lower vehicle body structure according to a third embodiment of the present invention. It is a perspective view showing the 1st floor cross member of the underbody structure of a car body in a third embodiment of the present invention, and the 2nd floor cross member. It is an exploded perspective view showing the 1st floor cross member of the underbody structure of a car body in a third embodiment of the present invention, and the 2nd floor cross member. FIG. 37 is an enlarged perspective view of a portion X in FIG. 36 in the lower vehicle-body structure according to the third embodiment of the present invention. FIG. 32 is a cross-sectional view showing an enlargement of a portion XI in FIG. 31 in the vehicle body lower structure according to the third embodiment of the present invention. FIG. 32 is a cross-sectional view showing an enlargement of a portion XII of FIG. 31 in the vehicle body lower portion structure in the third embodiment of the present invention. It is a perspective view which shows the state which fractured | ruptured the battery pack frame of the vehicle body lower part structure in 3rd embodiment of this invention. It is sectional drawing explaining the example which protects a battery from the impact load input from the vehicle side by the vehicle body lower structure in 3rd embodiment of this invention. It is sectional drawing which follows the vehicle front-back direction of the vehicle body lower structure in 3rd embodiment of this invention. It is sectional drawing which decomposes | disassembles and shows the principal part of FIG. It is a perspective view including a partial cross section which shows a seal member of underbody structure of a car body.

A first embodiment of the present invention will be described based on 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 of the vehicle.
As shown to FIG. 1, FIG. 2, the vehicle body 10 is provided with the vehicle body lower structure 12 which comprises the lower part of the vehicle body 10. As shown in FIG. The lower body structure 12 includes a left side sill (side sill) 14, a right side sill (side sill) 15, a floor panel 16, a floor cross member unit 17, an outer bulkhead unit 18 on the left, and an inner bulkhead unit 19 on the left. And an outer bulkhead unit 21 on the right side, 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.

The lower vehicle body structure 12 also includes a battery pack (under-floor mounting component (that is, in-vehicle component)) 28 (see FIG. 4), a battery pack frame 29 (see FIG. 4) And.
In addition, since the vehicle body lower part structure 12 is comprised by the substantially left-right symmetrical member, hereafter, each structural member on the left side is demonstrated and description of each structural member on the right side is abbreviate | omitted.

The left side sill 14 is provided on a left side portion (one of both side portions of the vehicle) 10a of both side portions of the vehicle body 10 and extends in the vehicle longitudinal direction. The right side sill 15 is provided on the right side (the other side of the both sides of the vehicle) 10b of the both sides of the vehicle body 10 and extends in the longitudinal direction of the vehicle.
A floor panel 16 is disposed between the left side sill 14 and the right side sill 15. The floor panel 16 is bridged between the left side sill 14 and the right side sill 15. The floor cross member unit 17 is attached to the upper surface 16 a of the floor panel 16. The floor cross member unit 17 includes a first floor cross member 34, a second floor cross member (floor cross member) 35, and a third floor cross member 36.

The first floor cross member 34 is disposed on the front side of the vehicle body in the passenger compartment 38. The first floor cross member 34 is mounted on the left side sill 14 and the right side sill 15 in the vehicle width direction.
The second floor cross member 35 is disposed on the vehicle rear side of the first floor cross member 34. The second floor cross member 35 is mounted on the left side sill 14 and the right side sill 15 in the vehicle width direction, and extends parallel to the first floor cross member 34.
The third floor cross member 36 is disposed on the vehicle rear side of the second floor cross member 35. The third floor cross member 36 is mounted on the left side sill 14 and the right side sill 15 in the vehicle width direction, and extends parallel to 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 vehicle longitudinal direction. 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 by a fastening member such as a bolt 37 or a nut. For example, a passenger sheet 32 is attached to the left half of the first floor cross member 34 and the second floor cross member 35 by fastening members such as bolts 41 and nuts 42 (see FIG. 4). In addition, a rear seat 43 is provided on the third floor cross member 36.

Thus, the driver seat 31 is attached to the right half of the first floor cross member 34 and the second floor cross member 35. 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 respectively bridged to the left side sill 14 and the right side sill 15.
The first floor cross member 34, the second floor cross member 35, and the third floor cross member 36 are similar members, and in the following, the second floor cross member 35 will be described in detail as the first and third floor cross members. Detailed description of the

members

34 and 36 is omitted. The second floor cross member 35 is hereinafter abbreviated as "floor cross member 35".

The left outer bulkhead unit 18 includes a first outer bulkhead (bulkhead) 51, a second outer bulkhead (bulkhead) 52, and a third outer bulkhead (bulkhead) 53.
The first outer bulkhead 51 is disposed on an extension of the first floor cross member 34. The second outer bulkhead 52 is disposed on an extension of the second floor cross member 35. The third outer bulkhead 53 is disposed on the extension 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, and in the following, the second outer bulkhead 52 will be described in detail as an "outer bulkhead 52", Detailed description of the third

outer bulkheads

51 and 53 is omitted.

As shown in FIG. 3, the left inner bulkhead unit 19 includes a first inner bulkhead (bulkhead) 55, a second inner bulkhead (bulkhead) 56, and a third inner bulkhead (bulkhead) 57. And have.
The first inner bulkhead 55 is disposed on the extension of the first floor cross member 34. The second inner bulkhead 56 is disposed on the extension of the second floor cross member 35. The third inner bulkhead 57 is disposed on the extension 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, and in the following, the second inner bulkhead 56 will be described in detail as the “inner bulkhead 56,” Detailed description of the third

inner bulkheads

55 and 57 is omitted.

Returning to FIG. 2, the left gusset unit 24 includes a first gusset (gusset) 61, a second gusset (gusset) 62, and a third gusset (gusset) 63.
The first gusset 61 is disposed below the inclined portion 99 on the left end side of the first floor cross member 34. The second gusset 62 is disposed 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 disposed 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, and hereinafter, the second gusset 62 will be described in detail as "the gusset 62". Omit.

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 outwardly bulging portion 71, an upper flange 72, and a lower flange 73. The outer bulging portion 71 is bulging 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 on the inner side in the vehicle width direction of the side sill outer 65. The side sill inner 66 has an inner bulging portion 76, an upper flange 77, and a lower flange 78. The inner bulged 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 inner 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 portion 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 side portion 67 a of the stiffener 67 is joined in a state of being sandwiched between the upper flange 72 of the side sill outer 65 and the upper flange 77 of the side sill inner 66. Further, the lower side portion 67 b of the stiffener 67 is joined in a state of being sandwiched between the lower flange 73 of the side sill outer 65 and the lower flange 78 of the side sill inner 66. 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 into an outer shape of a rectangular frame by a side sill outer 65 and a side sill inner 66. An upper side portion 67a of the stiffener 67 is interposed between the

upper flanges

72 and 77, and a lower side portion 67b of the stiffener 67 is interposed between the

lower flanges

73 and 78, whereby the stiffener 67 is disposed vertically.
An outer space (inside of the side sill) 88 is formed between the side sill outer 65 and the stiffener 67. Further, an inner space (inside of the side sill) 89 is formed between the side sill inner 66 and the stiffener 67.

As shown in FIGS. 6 and 7, the outer bulkhead 52 is disposed 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 joining 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. A 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 (the end away from the stiffener 67) of the side wall 84 is closed by the bottom 85. The bottom 85 is formed in a rectangular shape. An opening 87 (see also FIG. 5) is formed 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 along the outer surface 67c of the stiffener 67 toward the front of the vehicle body. The rear joint flange 86b extends from the other end of the rear side wall 84b along the outer surface 67c of the stiffener 67 toward the rear of the vehicle body. The upper joint flange 86c is extended upward along the outer surface 67c of the stiffener 67 from the other end of the upper side wall 84c. The lower joint flange 86d is extended downward along the outer surface 67c of the stiffener 67 from the other end of the lower side wall 84d.

That is, the joining 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. A front joint flange 86a, a rear joint flange 86b, an upper joint flange 86c, and a lower joint flange 86d that constitute the joint flange 86 are disposed 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) of a polygonal cross section (specifically, a rectangular cross section) in which the opening 87 is opened on the stiffener 67 side.

An inner bulkhead 56 is disposed in an inner space 89 between the side sill inner 66 and the stiffener 67. The inner bulkhead 56, like the outer bulkhead 52, has a side wall 91, a bottom 92, and a joining 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 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 (an end on the side of the stiffener 67). The opening 94 of the inner bulkhead 56 is a rectangular shape having the same shape as the opening 87 of the outer bulkhead 52.
A joining 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 extends from the other end of the front side wall 91a along the inner surface 67d of the stiffener 67 toward the front of the vehicle body.
The rear joint flange 93b extends from the other end of the rear side wall 91b along the inner surface 67d of the stiffener 67 toward the rear of the vehicle body. The upper joint flange 93c is extended upward along the inner surface 67d of the stiffener 67 from the other end of the upper side wall 91c. The lower joint flange 93d is extended downward along the inner surface 67d of the stiffener 67 from the other end of the lower side wall 91d.

That is, the joining 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. A front joint flange 93a, a rear joint flange 93b, an upper joint flange 93c, and a lower joint flange 93d that constitute the joint flange 93 are disposed in contact with the inner surface 67d of the stiffener 67.
The inner bulkhead 56 has a rectangular shape identical to the opening 87 of the outer bulkhead 52, and the opening 94 is opened on the stiffener 67 side, and is formed into a box of polygonal cross section (rectangular cross section in the first embodiment) It is done.

With the joining flange 86 of the outer bulkhead 52 being in contact with the outer surface 67 c of the stiffener 67 and the joining flange 93 of the inner bulkhead 56 being in contact with the inner surface 67 d of the stiffener 67 It is superimposed through. The overlapping joining flange 86 and the joining flange 93 are joined to each other via stiffeners 67.
Thus, 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 away from the stiffener 67 in the vehicle width direction away from the side wall 84. The outer bulkhead 52 is closed at one end of the side wall 84 away from the stiffener 67 by the bottom 85. The inner bulkhead 56 has a side wall 91 extending away from the stiffener 67 inward in the vehicle width direction. 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. Furthermore, the load F2 that has passed through the outer bulkhead 52 and the inner bulkhead 56 can be well supported by the floor cross member 35.
As described above, it is possible to absorb the impact energy by crushing the outer bulkhead 52 and the inner bulkhead 56 with the impact load F1 input from the side of the vehicle Ve.

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 (ie, the second floor cross member) 35. Thereby, for example, deformation of the vehicle body side portion such as the left side sill 14 to the passenger seat 32 can be suppressed. In addition, it is possible to suppress the deformation of the vehicle body side portion such as the right side sill 15 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 holes 96 in the stiffener 67, when the inside of the left side sill 14 is electrodeposited, the electrodeposition paint can be well guided to the inside of the left side sill 14 using the holes 96. Thereby, the electrodeposition paint can be easily attached to the inside of the left side sill 14.
Further, by forming the hole 96 in the stiffener 67, the weight of the stiffener 67 can be reduced, and the weight of the vehicle body 10 can be reduced.

As shown in FIGS. 4 and 6, the left side portion 16 c of the floor panel 16 is attached to the top (upper surface) 82 of the inner bulged portion 76 of the side sill inner 66. An upper portion 82 of the inner bulging portion 76 is a portion to be an upper portion of the left side sill 14. Hereinafter, the upper portion of the left side sill 14 is referred to as “upper side sill 82 (upper portion 82 of side sill)”.
The floor panel 16 is formed flat. Further, the left side portion 16 c of the floor panel 16 is attached to the side sill upper portion 82. Thus, the floor panel 16 is disposed 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 getting in and out of the occupant, and it is possible to ensure good getting in and out of the occupant.

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

The floor cross member 35 is attached to the upper surface 16 a of the floor panel 16 by joining the member front flange 104 and the member rear flange 105 to the upper surface 16 a 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 members 35 are formed substantially symmetrically (see also FIG. 2). Therefore, hereinafter, the left side of the floor cross member 35 will be described in detail, and the description of the right side will be omitted. The floor cross member 35 includes an end member 171, a straight portion member 172, and a center portion member 173 which are joined sequentially from the outer side to the center in the vehicle width direction.
The end member 171 is disposed on the left outside 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 from the inner end of the end member 171 inward in the vehicle width direction. The central member 173 extends inward in the vehicle width direction from the inner end of the linear member 172. The central member 173 is arranged to straddle the floor tunnel 192 of the floor panel 16.
The floor cross member 35 also includes an outer fastening bracket (fastening bracket) 141 and an inner fastening bracket (fastening bracket) 142.

A first floor cross member 34 is provided in front of the floor cross member (i.e., the second floor cross member) 35 at a predetermined interval. The first floor cross member 34 is formed substantially symmetrically in the same manner as the second floor cross member 35.
Like the second floor cross member 35, the first floor cross member 34 includes an end member 301, a straight portion member 302, and a center portion member 303 which are joined sequentially from the outer side to the center in the vehicle width direction . Further, the first floor cross member 34 includes 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.
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 similarly to the inner fastening bracket 142 of the floor cross member 35.
Accordingly, detailed description of the end member 301, the linear portion member 302, the central portion member 303, the outer fastening bracket 304, and the inner fastening bracket 305 of the first floor cross member 34 is 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 disposed on the left side sill 14 side.
The inclined portion 107 has an upper inclined portion 108, a joint seat 177, and a bead 178.
The upper inclined portion 108 is a portion that forms the upper portion of the inclined portion 107.
The joint seat portion 177 extends horizontally outward from the outer end 108 a of the upper inclined portion 108 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 side sill 82. 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 longitudinal 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 is extended in the vehicle width direction from the upper inclined portion 108 to the joint seat 177.

The bead 178 extends outward in the vehicle width direction from the portion 108 b in the middle of the upper inclined portion 108 to the outer edge of the joint seat 177. The bead 178 is formed to bulge upward. For example, a plurality of beads 178 are formed at intervals in the longitudinal direction of the vehicle body. In the first 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 177. Thus, the bead 178 is extended to intersect (specifically, orthogonally) the bending portion 179. Thus, 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, when the impact load F1 is input to the joint seat portion 177, the bending of the bent portion 179 can be suppressed by the bead 178. Thereby, the impact load F1 can be transmitted from the joint seat portion 177 through the bead 178 to the upper inclined portion 108, so that the load transmission can be prevented from being impaired.

Here, the upper inclined portion 108 is a portion that forms the upper portion of the inclined portion 107. The upper inclined portion 108 extends downward to the side sill upper portion 82 outward in the vehicle width direction. The outer end of the inclined portion 107 is closed by the upper inclined portion 108.
The outer end 108 a of the upper inclined portion 108 is located at the side sill upper portion 82. The joint seat 177 is joined to the side sill upper portion 82 via the left side portion 16 c of the floor panel 16.
The member front flange 104 of the end member 171 (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) It is joined to the left side portion 16c.
Thus, the outer end (that is, the joint seat 177) of the inclined portion 107 is joined to the side sill upper portion 82 through the left side portion 16 c of the floor panel 16.

The horizontal portion 175 extends parallel to the floor panel 16 from the inner end 107 a of the inclined portion 107 inward in the vehicle width direction. The left side sheet attachment portion 181 of the passenger seat 32 (see FIG. 11) is attached to an upper portion 175 a of the horizontal portion 175 by a bolt 41 and a nut 42.
The end member 171 is formed in a relatively complicated shape by closing the outer end of the inclined portion 107 with the upper inclined portion 108.

As shown in FIGS. 8 and 9, the inner end 171a of the end member 171 and the outer end 172a of the straight portion member 172 are joined in a state of being overlapped. By joining the inner end 171a of the end member 171 and the outer end 172a of the linear member 172, the first joint portion 184 is formed by the overlapped inner end 171a and the outer end 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 185, an outer leg 186, an inner leg 187, an outer upper flange 188, and an inner upper flange 189.
The bottom portion 185 is disposed along the floor panel 16 and is fastened to the upper portion 133 b of the outer fastening member 133 via the floor panel 16 by a bolt 165 and a nut 166. The outer leg portion 186 is raised from the outer side of the bottom portion 185 to the upper portion 175 a of the horizontal portion 175 (that is, the inner end 171 a of the end member 171). The inner leg 187 is raised from the inner side of the bottom 185 to the straight portion member 172. The outer fastening bracket 141 is formed in a U-shaped cross section by the bottom portion 185, the outer leg portion 186 and the inner leg portion 187.

An outer upper flange 188 extends outward in the vehicle width direction from the upper end of the outer leg portion 186 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 held between the inner end 171 a of the end member 171 and the outer end 172 a of the straight portion member 172.
The bottom portion 185 of the outer fastening bracket 141 is fastened to the upper portion 133 b of the outer fastening member 133 via the floor panel 16 by a bolt 165 and a nut 166. The outer fastening bracket 141 uses a high strength member to support the battery pack 28. Thus, the first joint portion 184 is reinforced by the outer upper flange 188.
The inner upper flange 189 is bent from the upper end of the inner leg portion 187 and extends inward in the vehicle width direction along the inner surface (lower surface) of the straight portion member 172. The inner upper flange 189 is joined to the lower surface of the straight portion member 172.

As shown in FIGS. 9 and 12, the central member 173 is disposed so as to cross (orthogonal) the floor tunnel 192 of the floor panel 16, and is mounted so as to straddle the floor tunnel 192. The central member 173 has an upper portion 173b extending in the vehicle width direction and a raised portion 194 raised at the center in the vehicle width direction. The right side sheet attachment portion 182 of the passenger seat 32 (see FIG. 11) is attached to an upper portion 173 b of the central member 173 by a bolt 41 and a nut 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 173 a of the central member 173 and the inner end portion 172 b of the linear portion member 172 are joined in a state where they are superimposed on each other. The left end 173a of the central member 173 and the inner end 172b of the linear member 172 are joined to form a second joint 196 between the left end 173a and the inner end 172b. An inner fastening bracket 142 is joined to the second joint portion 196.

Similar to the outer fastening bracket 141, the inner fastening bracket 142 has a bottom 202, an outer leg 203, an inner leg 204, an outer upper flange 205, and an inner upper flange 206.
The bottom portion 202 is disposed along the floor panel 16 and is fastened to the upper portion 133 b of the outer fastening member 133 via the floor panel 16 by a bolt 167 and a nut 168. The outer leg portion 203 is raised from the outer side portion of the bottom portion 202 to the straight portion member 172. The inner leg 204 is raised from the inside of the bottom 202 to the top 173 b of the central member 173. The inner fastening bracket 142 is formed to have a U-shaped cross section by the bottom portion 202, the outer leg portion 203 and the inner leg portion 204.

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

A raised portion 194 is formed in a U-shape on the central member 173. For this reason, the central member 173 is formed in a relatively complicated shape as the end member 171 is.
On the other hand, the linear portion member 172 linearly extends from the end member 171 to the central portion member 173. Therefore, the linear 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 portion member 173 of the floor cross member 35 is formed, for example, in accordance with the floor tunnel 192. For this reason, the end member 171 and the central 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.
Thus, the floor cross member 35 is divided into three members of the end member 171, the linear portion member 172, and the central portion member 173. Therefore, for example, the end member 171 and the central member 173 having a complicated shape can be draw-formed (drawn), and the linear member 172 having a simple shape can be bend-formed (bent). By bending the straight portion member 172 in this manner, the manufacturing cost of the floor cross member 35 can be reduced.

In addition, it is possible to optimize the collision mode by making the strengths of the end member 171, the linear portion member 172, and the central portion member 173 different. In this case, a device for securing the strength of the first joint portion 184 (see FIG. 11) between the end member 171 and the linear portion member 172 and the second joint portion 196 between the linear portion member 172 and the central portion member 173 Be 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. As the outer fastening bracket 141 and the inner fastening bracket 142, high strength members are used to support under floor mounting components such as the battery pack 28.
Therefore, the outer fastening bracket 141 is joined to the first joint portion 184 and the inner fastening bracket 142 is joined to the second joint portion 196, whereby the first joint portion 184 is reinforced by the outer fastening bracket 141, and the second joint is formed. The part 196 is reinforced by the inner fastening bracket 142. Thereby, the load transfer performance of the floor cross member 35 in the vehicle width direction can be secured, and the impact load F1 input from the side of the vehicle Ve can be favorably 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 102, and a member rear wall 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 back wall portion 103 extends from the back side of the slope portion 107 to the floor panel 16.
The inclined portion 107 is formed in a U-shape at the upper inclined portion 108, the member front wall portion 102, and the member rear wall portion 103.

A gusset 62 is disposed below the floor cross member 35. The gusset 62 is bridged by the inner wall 81 of the inner bulged portion 76 of the side sill inner 66 and the lower surface 16 b of the floor panel 16. Hereinafter, the inner wall 81 of the inner bulging portion 76 is referred to as “side sill inner wall 81 (inner wall 81 of side sill)”.
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 plan view. The gusset inclined portion 111 is extended downward to the outside in the vehicle width direction from the lower surface 16 b of the floor panel 16 to the side sill inner wall 81.
The gusset front wall portion 112 extends from the front side of the gusset inclined portion 111 to the left side portion 16 c 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 16 c of the floor panel 16.

As shown in FIGS. 5 and 13, a gusset front wall 112 projects from the front side of the gusset inclined portion 111 toward the floor panel 16. A gusset rear wall 113 projects from the rear side of the gusset inclined portion 111 toward the floor panel 16. A gusset 62 is formed in a U-shaped cross section by the gusset inclined portion 111, the gusset front wall portion 112, and the gusset rear wall portion 113.
A gusset flange 114 protrudes from the lower side of the gusset inclined portion 111.

Gusset flanges

115 and 116 respectively project from the side 112 a and the upper side 112 b of the gusset front wall 112.

Gusset flanges

117 and 118 respectively project from the side 113 a and the upper side 113 b of the gusset rear wall 113.

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

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

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. The gusset 62 has a gusset flange 116 and a gusset flange 118 joined to the floor panel 16.
Further, the sloped portion 107 of the floor cross member 35 is formed in a U-shape by the upper sloped portion 108, the member front wall portion 102, and the member back wall portion 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 16 c of the floor panel 16. The member rear flange 105 is joined to the gusset flange 118 via the left side portion 16 c of the floor panel 16.
That is, the floor cross member 35 and the gusset 62 are joined in a state in which the floor panel 16 is interposed.

Thus, 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 back 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. The floor cross member 35 and the gusset 62 are joined together with the left side portion 16 c of the floor panel 16 interposed therebetween.
Thus, the floor cross member 35 and the gusset 62 form a closed cross section with high rigidity. Thus, 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 as in the case of the floor cross member (ie, the second floor cross member) 35. Therefore, a highly rigid closed cross section is formed by the first floor cross member 34 and the first gusset 61. Thus, 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 inclined section 107 and the gusset 62 form a cross section. Further, the linear portion 35 a of the floor cross member 35 is formed in a cross section.

Therefore, the strength of the inclined portion 107 is secured in the same manner as the linear portion 35 a of the floor cross member 35. Thus, 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 through 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.

Furthermore, by providing the floor cross member 35 on the upper surface 16 a of the floor panel 16, the floor cross member can be removed from below the floor panel 16. Thus, the space under the floor panel 16 can be increased. Thereby, the capacity of the under-floor mounting component such as 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 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 124, a case bottom 125, and a case flange 126.
The case wall portion 124 has a front wall, a rear wall, a left side wall 124 a 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 124 a, and the right side wall.

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

The opening 127 of the battery case 121 is closed from above by the lid 122. The lid 122 has a lid wall portion 135, a lid top portion 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 135 is formed in the same manner as the case wall 124.
The upper end portion of the lid wall portion 135 is closed by the lid top portion 136, and the opening portion 138 is formed at the lower end portion. A lid flange 137 protrudes from the entire circumference of the opening 138 of the lid wall 135 to the outside of the lid 122.

By overlapping the lid flange 137 with the case flange 126 from above, the gap between the lid flange 137 and the case flange 126 is sealed by the seal member. Accordingly, the opening 127 of the battery case 121 is closed by the lid 122. The battery 123 is accommodated in the inside 129 of the battery pack 28. When the opening 127 of the battery case 121 is closed by the lid 122, the upper portion 133b of the fastening member 133 protrudes upward from the opening of the lid top 136.

The protruded upper portion 133 b is fastened to the outer fastening bracket 141 of the floor cross member 35 by a bolt 165 and a nut 166. The projecting upper portion 133 b is fastened to the inner fastening bracket 142 of the floor cross member 35 with a bolt 167 and a nut 168. Thus, 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 the plurality of fastening members 133 and the like.

As shown in FIGS. 5 and 15, the battery pack 28 is disposed on the inner side in the vehicle width direction of the left side sill 14. 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 124 a (the outer periphery of the battery pack 28) of the case wall 124. The battery pack frame 29 is formed to have 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 a lower portion (lower surface) 83 of the inner bulging portion 76. The lower portion 83 of the inner bulging portion 76 is a portion that is the lower portion of the left side sill 14. Hereinafter, the lower part of the left side sill 14 will be referred to as the “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 disposed to face the inner bulkhead 56 via the side sill inner wall 81.

The frame body 144 has an inner wall 146, an outer wall 147, a top 148, a bottom 149, and a lower flange 151. A frame body 144 is formed in a rectangular frame shape in cross section by the inner wall 146, the outer wall 147, the top 148, and the bottom 149.
The inner wall 146 of the frame body 144 is joined along the left side wall 124 a of the case wall 124. Furthermore, the inner wall 146 is also joined to the flange 131a of the battery cross member 131 via the left side wall 124a. That is, the frame main 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. A 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, an inner wall portion 157, an upper flange 158, and a lower flange 159. At the top portion 154, the outer wall portion 155, and the bottom portion 156, the fixing portion 143 is formed to have a U-shaped cross section. The upper flange 158 is joined along the outer wall 147 of the frame body 144. The lower flange 159 is joined along the lower flange 151 of the frame body 144.
A collar 162 is interposed in the inside 161 of the fixing portion 143, and a bolt 163 is penetrated in the collar 162. The fixing portion 143 is attached to the side sill lower portion 83 by a bolt 163 and a nut 164.

Thus, the fixing portion 143 is attached to the side sill lower portion 83, and the frame main body 144 of the battery pack frame 29 is raised toward the side sill inner wall 81. The frame body 144 is opposed to the inner bulkhead 56 via the side sill inner wall 81. Further, the frame main body 144 is joined to the flange 131 a 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 main body 144, and the battery cross member 131 supports the load F4. be able to. Further, the load F5 is transmitted from the inner bulkhead 56 to the frame main body 144 and the battery cross member 131 from the inner bulkhead 56 through the impact load F1 input from the side of the vehicle Ve and the battery cross member 131 supports the load F5. it can.

Then, the outer bulkhead 52 and the inner bulkhead 56 can be sufficiently crushed by the impact load F1 to absorb impact energy well, and the battery 123 housed in the interior 129 of the battery pack 28 can be protected from the impact load F1.
Further, by supporting the load F4 and the load F5 by the battery cross member 131, the fixing portion 143 and the frame main body 144 (that is, the battery pack frame 29) can be crushed. Thereby, impact energy can be absorbed better and the battery 123 can be protected from the impact load F1.

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

Bonding flanges

86 and 93 of the outer bulkhead 52 and the inner bulkhead 56 are bonded to each other through stiffeners 67. Thus, the box-like shape of the outer bulkhead 52 is restrained by the joining flange 86. Further, the box-like shape of the inner bulkhead 56 is restrained by the joining flange 93.
As a result, when the outer bulging portion 71 abuts on the bottom portion 85 of the outer bulkhead 52, the impact load F6 is transmitted to the entire region (that is, the entire circumference) of the side wall 84 of the outer bulkhead 52. Further, the impact load F6 is transmitted to the entire region (that is, the entire circumference) of the side wall 91 of the inner bulkhead 56.
By 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 collapsed by the impact load F6 and 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 a load F7. In addition, the remaining load is transmitted to the battery cross member 131 as a load F8 through the fixing portion 143 and the frame main body 144. Furthermore, the remaining load is transmitted to the battery cross member 131 as the load F9 through the frame body 144.

The load F7 is supported by the floor cross member 35. The load F 8 and the load F 9 are supported by the battery cross member 131. Accordingly, 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 favorably absorbed by the outer bulkhead 52 and the inner bulkhead 56.
Furthermore, by supporting the load F8 and the load F9 by the battery cross member 131, the fixing 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 well absorbed by the battery pack frame 29.
Thereby, the battery 123 accommodated in the inside 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 first embodiment described above, and various modifications can be made without departing from the scope of the present invention.
For example, in the first embodiment, the battery pack 28 is illustrated as the under-floor mounting component (that is, the on-vehicle component), but the present invention is not limited to this. As another example, it is also possible to use a fuel tank, a fuel cell stack, or the like as an underfloor mounting component.

A second embodiment of the present invention will be described based on 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 of the vehicle.
As shown in FIG. 17 and FIG. 18, the vehicle body 10 is provided with a vehicle body lower structure 12 which constitutes the lower part of the vehicle body 10. The lower body structure 12 includes a left side sill 14, a right side sill 15, a floor panel 16, a floor cross member unit 17, a fastening unit 210 (see FIG. 21), and a battery pack (under-floor mounted component) 28 (see FIG. 21). And driver seat 31 and passenger seat 32.
In addition, since the vehicle body lower part structure 12 is comprised by the substantially left-right symmetrical member, hereafter, each structural member on the left side is demonstrated and description of each structural member on the right side is abbreviate | omitted.

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

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 vehicle longitudinal direction. 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 by a fastening member such as a bolt 37 or a nut. For example, a passenger sheet 32 is attached to the left half of the first floor cross member 34 and the second floor cross member 35 by fastening members such as bolts 41 and nuts 42 (see FIG. 21). In addition, a rear seat 43 is provided on the third floor cross member 36.

Thus, the driver seat 31 is attached to the right half of the first floor cross member 34 and the second floor cross member 35. A passenger seat 32 (see also FIG. 19) is attached to the left half of the first floor cross member 34 and the second floor cross member 35.
The driver sheet 31 and the passenger sheet 32 are symmetrical members, and the passenger sheet 32 will be described in detail below, and the driver sheet 31 will not be described.

The first floor cross member 34 has a first front fastening seat (fastening seat) 23 and a second front fastening seat (fastening seat) 240 in the left half. The first front fastening seat portion 23 is formed in a portion near the left end portion 34 a of the first floor cross member 34. The second front fastening seat portion 240 is formed in a portion near the center 34 b of the first floor cross member 34.
The second floor cross member 35 has a first rear fastening seat (fastening seat) 250 and a second rear fastening seat (fastening seat) 26 in the left half. The first rear fastening seat 250 is formed at a position near the left end 350 a of the second floor cross member 35. The second rear fastening seat portion 26 is formed in a portion near the center 35 b of the second floor cross member 35.
The passenger seat 32 is attached to the first front fastening seat 23, the first rear fastening seat 250, the second front fastening seat 240, and the second rear fastening seat 26 by bolts 41 and nuts 42 (see FIG. 21) It is done.

As shown in FIG. 19, the passenger sheet 32 includes a seat cushion 510, a seat back 520, a seat attachment portion 530, and a tongue support portion (belt support portion) 540.
The seat cushion 510 is provided along the floor panel 16 so that a passenger can be seated. The seat back 520 is raised from the rear of the seat back 520 so as to support the upper body of the occupant seated on the seat cushion 510.
The seat attachment portion 530 includes an outer seat rail 560 and an inner seat rail 570 as a pair of seat support portions. Hereinafter, the outer seat rail 560 is referred to as "first seat rail (first seat support portion) 560". The inner seat rail 570 is referred to as “second seat rail (second seat support portion) 570”.
The first seat rail 560 and the second seat rail 570 are spaced apart in the vehicle width direction.
The first seat rail 560 includes a first fixed rail 710, a first movable rail 720, and a first support bracket 730.

As shown in FIG. 20, the first fixed rail 710 is attached to the first front fastening seat 23 and the first rear fastening seat 250. The first fixed rail 710 is attached to the first front fastening seat 23 and the first rear fastening seat 250, whereby the first fixed rail 710 extends in the vehicle longitudinal direction.
A first movable rail 720 (see FIG. 19) is slidably connected to the first fixed rail 710 in the longitudinal direction of the vehicle body.
The first movable rail 720 is attached to the outer side portion 510 a of the seat cushion 510 via the first support bracket 730 (see FIG. 19).

As shown in FIGS. 18 and 19, the second seat rail 570 is configured to be substantially symmetrical with the first seat rail 560. That is, the second seat rail 570 includes the second fixed rail 750, the second movable rail 760, and the second support bracket 770.
The second fixed rail 750 is attached to the second front fastening seat 240 and the second rear fastening seat 26. The second fixed rail 750 is attached to the second front fastening seat portion 240 and the second rear fastening seat portion 26, whereby the second fixed rail 750 extends in the vehicle longitudinal direction in parallel with the first fixed rail 710. A second movable rail 760 is slidably connected to the second fixed rail 750 in the longitudinal direction of the vehicle body.
The second movable rail 760 is attached to the inner portion 510 b of the seat cushion 510 via the second support bracket 770.
Thus, the passenger seat 32 is slidably supported by the seat mounting portion 530 in the longitudinal direction of the vehicle body.

Thus, the first seat rail 560 is a seat rail extending in the longitudinal direction of the vehicle body. The second seat rail 570 is a seat rail extending in the longitudinal direction of the vehicle body. A first seat rail 560 is attached to the first front fastening seat 23 of the first floor cross member 34 and the first rear fastening seat 250 of the second floor cross member 35. A second seat rail 570 is attached to the second front fastening seat portion 240 of the first floor cross member 34 and the second rear fastening seat portion 26 of the second floor cross member 35.
Therefore, the rigidity of the first floor cross member 34 and the second floor cross member 35 is sufficiently ensured by the first seat rail 560 and the second seat rail 570.

The tongue support portion 540 is connected to the second support bracket 770. The tongue support portion 540 includes a support bracket 840 and a buckle 850. The lower end portion of the support bracket 840 is connected to the second support bracket 770 with a bolt and a nut. A buckle 850 is attached to the upper end of the support bracket 840.

As shown in FIG. 17, the tongue 880 of the seat belt 870 is inserted into the buckle 850. The tongue 880 of the seat belt 870 is locked to the buckle 850. Thus, the tongue 880 inserted into the buckle 850 is connected to the buckle 850.
In this state, for example, when the impact load F10 is input from the front of the vehicle Ve, the occupant is held in a state of being restrained by the seat belt 870. At this time, a tensile load (load) F20 acts on the tongue support portion 540 via the seat belt 870.

As shown in FIG. 21, 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 inner 66 is provided on the inner side in the vehicle width direction of the side sill outer 65. The stiffener 67 is interposed between the side sill outer 65 and the side sill inner 66.
The left side sill 14 is formed into an outer shape of a rectangular frame by a side sill outer 65 and a side sill inner 66.

As shown in FIGS. 22 and 23, the second floor cross members 35 are formed substantially symmetrically (see also FIG. 18). Therefore, hereinafter, the left side of the second floor cross member 35 will be described in detail, and the description of the right side will be omitted.
The second floor cross member 35 includes an end member 171, a straight portion member 172, and a central portion member 173 which are joined in order from the outside in the vehicle width direction toward the center.
The end member 171 is disposed on the left outside 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 from the inner end of the end member 171 inward in the vehicle width direction. The central member 173 extends inward in the vehicle width direction from the inner end of the linear member 172. The central member 173 is arranged to straddle the floor tunnel 192 of the floor panel 16.

In addition, the second floor cross member 35 includes an outer fastening bracket (fastening bracket) 141 and an inner fastening bracket (fastening bracket) 142.
The outer fastening bracket 141 is a member that constitutes a part of the outer fastening unit (fastening unit) 210A. The inner fastening bracket 142 is a member that constitutes a part of the inner fastening unit (fastening unit) 210B.

A first floor cross member 34 is provided at a predetermined distance in front of the second floor cross member 35 in the vehicle body. The first floor cross member 34 is formed substantially symmetrically in the same manner as the second floor cross member 35.
Like the second floor cross member 35, the first floor cross member 34 includes an end member 301, a straight portion member 302, and a center portion member 303 which are joined sequentially from the outer side to the center in the vehicle width direction . Further, the first floor cross member 34 includes an outer fastening bracket (fastening bracket) 304 and an inner fastening bracket (fastening bracket) 305.
The outer fastening bracket 304 is a member that constitutes a part of the outer fastening unit (fastening unit). The inner fastening bracket 305 is a member that constitutes a part of the inner fastening unit (fastening unit).

The end member 301 is formed in the same manner as the end member 171 of the second floor cross member 35. The straight portion member 302 is formed in the same manner as the straight portion member 172 of the second floor cross member 35. The central member 303 is formed in the same manner as the central member 173 of the second floor cross member 35.
The outer fastening bracket 304 is formed in the same manner as the outer fastening bracket 141 of the second floor cross member 35. The inner fastening bracket 305 is formed similarly to the inner fastening bracket 142 of the second floor cross member 35.
Accordingly, detailed description of the end member 301, the linear portion member 302, the central portion member 303, the outer fastening bracket 304, and the inner fastening bracket 305 of the first floor cross member 34 is omitted.

As shown in FIG. 24, the end member 171 has an inclined portion 107 and a horizontal portion 175. The inclined portion 107 is disposed on the left side sill 14 side.
The inclined portion 107 has an upper inclined portion 108, a joint seat 177, and a bead 178.
The upper inclined portion 108 is a portion that forms the upper portion of the inclined portion 107.
The joint seat 177 extends horizontally outward from the outer end 108 a of the upper inclined portion 108 in the vehicle width direction and is joined to the upper portion 82 of the left side sill 14.
Hereinafter, the upper portion 82 of the left side sill 14 will be referred to as 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 side sill 82. 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 longitudinal direction of the vehicle body. Therefore, when the impact load F3 is input from the side of the vehicle Ve, it is conceivable that the bending portion 179 is bent by the input impact load F3. Therefore, the bead 178 is extended in the vehicle width direction from the upper inclined portion 108 to the joint seat 177.

The bead 178 extends outward in the vehicle width direction from the portion 108 b in the middle of the upper inclined portion 108 to the outer edge of the joint seat 177. The bead 178 is formed to bulge upward. For example, a plurality of beads 178 are formed at intervals in the longitudinal direction of the vehicle body. In the second 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 177. Thus, the bead 178 is extended to intersect (specifically, orthogonally) the bending portion 179. Thus, the bent portion 179 can be reinforced by the bead 178 with respect to the impact load F3 input from the side of the vehicle Ve to the joint portion.
That is, when the impact load F3 is input to the joint seat portion 177, the bending of the bent portion 179 can be suppressed by the bead 178. As a result, the impact load F3 can be transmitted from the joint seat portion 177 through the bead 178 to the upper inclined portion 108, and load transmission can be prevented from being impaired.

The horizontal portion 175 extends parallel to the floor panel 16 from the inner end of the inclined portion 107 inward in the vehicle width direction. A first rear fastening seat 250 is formed at an upper portion 175 a of the horizontal portion 175. The first rear fastening seat 250 is formed at the vehicle width direction end of the second floor cross member 35. The first seat rail 560 of the passenger seat 32 (see FIG. 21) is attached to the first rear fastening seat 250 by bolts 41 and nuts 42.
The end member 171 is formed in a relatively complicated shape by closing the outer end of the inclined portion 107 with the upper inclined portion 108.

As shown in FIGS. 22 and 23, the inner end 171a of the end member 171 and the outer end 172a of the straight portion member 172 are joined in a state of being overlapped. By joining the inner end 171a of the end member 171 and the outer end 172a of the linear member 172, the first joint portion 184 is formed by the overlapped inner end 171a and the outer end 172a. ing. An outer fastening bracket 141 is joined to the first joint portion 184.

As shown in FIGS. 24 and 25, the outer fastening bracket 141 has a bottom portion 185, an outer leg portion (bulk head portion) 186, an inner leg portion (bulk head portion) 187, and an outer upper flange (upper flange) 188. And an inner upper flange 189.
The bottom portion 185 is disposed along the floor panel 16, and is fastened to the upper portion 133 b of the outer fastening member (fastening member) 133 with a bolt 165 and a nut 166 via the floor panel 16. The outer fastening member 133 is a member that constitutes a part of the outer fastening unit 210A (210).
The outer leg portion 186 is raised from the outer side of the bottom portion 185 to the upper portion 175 a of the horizontal portion 175 (that is, the inner end 171 a of the end member 171). The inner leg 187 is raised from the inner side of the bottom 185 to the inner end 172 b of the straight portion member 172. The outer fastening bracket 141 is formed in a U-shaped cross section by the bottom portion 185, the outer leg portion 186 and the inner leg portion 187.

An outer upper flange 188 extends outward in the vehicle width direction from the upper end of the outer leg portion 186 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 held between the inner end 171 a of the end member 171 and the outer end 172 a of the straight portion member 172. Thus, the outer upper flange 188 of the outer fastening bracket 141 is firmly supported between the inner end 171a and the outer end 172a.
A bottom portion 185 of the outer fastening bracket 141 is fastened to an upper portion 133 b of the outer fastening member 133 with a bolt 165 and a nut 166 via the floor panel 16. The outer fastening bracket 141 uses a high strength member to support the battery pack 28. Thus, the first joint portion 184 is reinforced by the outer upper flange 188.

A first rear fastening seat 250 is formed on the outer side in the vehicle width direction of the first joint 184 and in the vicinity of the first joint 184. Therefore, the first seat rail 560 of the passenger sheet 32 is attached by the bolt 41 and the nut 42 in the vicinity of the first joint portion 184 (that is, the outer upper flange 188).
An inner upper flange 189 extends inward in the vehicle width direction along the inner surface of the straight portion member 172 from the upper end of the inner leg portion 187. The inner upper flange 189 is joined to the straight portion member 172.

As shown in FIGS. 23 and 26, the central member 173 is disposed so as to cross (orthogonal) the floor tunnel 192 of the floor panel 16, and is mounted so as to straddle the floor tunnel 192 laterally. The central member 173 has an upper portion 173b extending in the vehicle width direction and a raised portion 194 raised at the center in the vehicle width direction. A second rear fastening seat 26 is formed at an upper portion 173 b of the central member 173. The second rear fastening seat portion 26 is formed on the center side in the vehicle width direction of the second floor cross member 35. The second seat rail 570 of the passenger seat 32 is attached to the second rear fastening seat 26 by 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 173 a of the central member 173 and the inner end portion 172 b of the linear portion member 172 are joined in a state of being overlapped. The left end 173a of the central member 173 and the inner end 172b of the linear member 172 are joined to form a second joint 196 between the left end 173a and the inner end 172b. An inner fastening bracket 142 is joined to the second joint portion 196.

Similar to the outer fastening bracket 141, the inner fastening bracket 142 has a bottom 202, an outer leg (bulk head) 203, an inner leg (bulk head) 204, an outer upper flange 205, and an inner upper flange Upper flange) 206, and
The bottom portion 202 is disposed along the floor panel 16 and is fastened to the upper portion 134 b of the inner fastening member (fastening member) 134 by the bolt 167 and the nut 168 via the floor panel 16. The inner fastening member 134 is a member that constitutes a part of the inner fastening unit 210B (210). The outer leg portion 203 is raised from the outer side portion of the bottom portion 202 to the inner end portion 172 b of the linear portion member 172. The inner leg 204 is raised from the inside of the bottom 202 to the top 173 b of the central member 173. The bottom portion 202, the outer leg portion 203 and the inner leg portion 204 form an inner fastening bracket 142 in a U-shaped cross section.

An 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 173 b of the central portion member 173. The inner upper flange 206 is joined to the second joint 196 in a state of being sandwiched between the left end 173 a and the inner end 172 b. Therefore, the inner upper flange 206 of the inner fastening bracket 142 is firmly supported between the left end portion 173a and the inner end portion 172b.
A bottom portion 202 of the inner fastening bracket 142 is fastened to an upper portion 134 b of the inner fastening member 134 by a bolt 167 and a nut 168 via the floor panel 16. The inner fastening bracket 142 uses a high strength member to support the battery pack 28. Thus, the second joint portion 196 is reinforced by the inner upper flange 206.

A second rear fastening seat 26 is formed on the inner side in the vehicle width direction of the second joint 196 and in the vicinity of the second joint 196. Therefore, the second seat rail 570 of the passenger sheet 32 is attached by the bolt 41 and the nut 42 in the vicinity of the second joint portion 196 (that is, the inner upper flange 206).
An outer upper flange 205 extends along the inner surface of the straight portion member 172 outward in the vehicle width direction from the upper end of the outer leg portion 203. 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 member 173. For this reason, the central member 173 is formed in a relatively complicated shape.
On the other hand, the linear portion member 172 linearly extends from the end member 171 to the central portion member 173. Therefore, the linear portion member 172 is formed in a relatively simple shape.

Here, the end member 171 of the second floor cross member 35 is joined to the left side sill 14. Further, the central portion member 173 of the second floor cross member 35 is formed, for example, in accordance with the floor tunnel 192. For this reason, the end member 171 and the central 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.
Thus, the second floor cross member 35 is divided into three members of the end member 171, the linear portion member 172, and the central portion member 173. Therefore, for example, the end member 171 and the central member 173 having a complicated shape can be draw-formed (drawn), and the linear member 172 having a simple shape can be bend-formed (bent). As described above, by bending the linear portion member 172, the manufacturing cost of the second floor cross member 35 can be reduced.

In addition, it is possible to optimize the collision mode by making the strengths of the end member 171, the linear portion member 172, and the central portion member 173 different. In this case, a device for securing the strength of the first joint portion 184 (see FIG. 25) of the end member 171 and the linear portion member 172 and the second joint portion 196 of the linear portion member 172 and the central portion member 173 is required. Be 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 use high strength members to support the battery pack 28.

Therefore, the outer fastening bracket 141 is joined to the first joint portion 184 and the inner fastening bracket 142 is joined to the second joint portion 196, whereby the first joint portion 184 is reinforced by the outer fastening bracket 141, and the second joint is formed. The part 196 is reinforced by the inner fastening bracket 142. Thereby, load transfer performance in the vehicle width direction of the second floor cross member 35 can be secured, and the second floor cross member 35 supports the impact load F10 (see also FIG. 25) input from the side of the vehicle Ve well. be able to.

As shown in FIGS. 18 and 22, in the first floor cross member 34, as in the second floor cross member 35, the first front fastening seat 23 is formed on the end member 301, and the first floor cross member 34 is formed on the center member 303. 2 The front fastening seat 240 is formed. The first front fastening seat portion 23 is formed on the end side of the first floor cross member 34 in the vehicle width direction. The second front fastening seat portion 240 is formed on the center side in the vehicle width direction of the first floor cross member 34.

The first front fastening seat 23 is formed on the outer side in the vehicle width direction of the first joint 197 and in the vicinity of the first joint 197. Thus, the first seat rail 560 (see FIG. 19) of the passenger sheet 32 is attached by bolts and nuts in the vicinity of the first joint portion 197 (ie, the outer upper flange 307 (see FIG. 23) of the outer fastening bracket 304). ing.
The second front fastening seat portion 240 is formed on the inner side in the vehicle width direction of the second joint portion 198 and in the vicinity of the second joint portion 198. Thus, the second seat rail 570 (see FIG. 19) of the passenger sheet 32 is attached by bolts and nuts in the vicinity of the second joint 198 (ie, the inner upper flange 308 (see FIG. 23) of the inner fastening bracket 305). ing.

Referring back to FIGS. 20 and 21, the sloped portion 107 has an upper sloped portion 108, a front wall (member front wall) 102, and a rear wall (member rear wall) 103. The front wall portion 102 extends from the front side of the upper inclined portion 108 to the floor panel 16. The 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 at the upper inclined portion 108, the front wall portion 102, and the rear wall portion 103.

The second gusset 62 is disposed below the second floor cross member 35. The second gusset 62 is bridged between the inner wall 81 of the side sill inner 66 and the lower surface 16 b of the floor panel 16. Hereinafter, the inner wall 81 of the side sill inner 66 is referred to as “side sill inner wall 81”.
The second gusset 62 has a gusset inclined portion 111, a gusset front wall 112, a gusset rear wall 113, and

gusset flanges

116 and 118. The gusset inclined portion 111 is extended downward to the outside in the vehicle width direction from the lower surface 16 b of the floor panel 16 to the side sill inner wall 81.
The gusset front wall portion 112 extends from the front side of the gusset inclined portion 111 to the left side portion 16 c 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 16 c of the floor panel 16.

The second gusset 62 is formed in a U-shape by the gusset inclined portion 111, the gusset front wall 112, and the gusset rear wall 113. The second gusset 62 has a gusset flange 116 and a gusset flange 118 joined to the floor panel 16.
Further, the sloped portion 107 of the second floor cross member 35 is formed in a U shape by the upper sloped portion 108, the front wall portion 102 and the rear wall portion 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 16 c of the floor panel 16. The member rear flange 105 is joined to the gusset flange 118 via the left side portion 16 c of the floor panel 16.
That is, the second floor cross member 35 and the second gusset 62 are joined in a state in which the floor panel 16 is interposed.

Thus, the second floor cross member 35 is formed in a U-shape by the upper inclined portion 108, the front wall portion 102 and the rear wall portion 103. The second gusset 62 is formed in a U-shape by the gusset inclined portion 111, the gusset front wall 112, and the gusset rear wall 113. Further, the second floor cross member 35 and the second gusset 62 are joined in a state in which the left side portion 16 c of the floor panel 16 is interposed.
Therefore, a highly rigid closed cross section is formed by the second floor cross member 35 and the second gusset 62. Thereby, the impact load F3 input from the side of the vehicle Ve can be transmitted from the left side sill 14 to the second floor cross member 35.

The first floor cross member 34 is joined to the first gusset 61 with the floor panel 16 interposed as in the case of the floor cross member (ie, the second floor cross member) 35. Therefore, a highly rigid closed cross section is formed by the first floor cross member 34 and the first gusset 61. Thereby, the impact load F10 input from the side of the vehicle Ve can be transmitted from the left side sill 14 to the first floor cross member 34.

As shown in FIGS. 19 and 21, a battery pack 28 is provided between the left side sill 14 and the right side sill 15 (see FIG. 18) 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 124, a case bottom 125, and a case flange 126.
The case wall portion 124 has a front wall, a rear wall, a left side wall 124 a 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 124 a, and the right side wall.

The lower end portion of the case wall portion 124 is closed by the case bottom portion 125, and an opening portion 127 is formed at the upper end portion. A case flange 126 projects from the entire circumference of the opening 127 of the case wall 124 to the outside of the battery case 121.
A battery cross member (under floor cross member) 131 is attached to the inside of the battery case 121 (that is, the inside 129 of the battery pack 28). The battery cross member 131 extends in the vehicle width direction at the inside 129 of the battery pack 28.

The battery cross member 131 is attached to the first floor cross member 34 (see FIG. 18) and the second floor cross member 35 by a plurality of fastening units 210.
Hereinafter, among the plurality of fastening units 210, a pair of fastening units 210 provided in the left half of the second floor cross member 35 will be described as a representative example. Hereinafter, the pair of fastening units 210 will be described as the outer fastening unit 210A and the inner fastening unit 210B for the sake of convenience.

As shown in FIG. 25, the outer fastening unit 210 </ b> A includes an outer fastening bracket 141 and an outer fastening member 133.
The outer fastening bracket 141 is provided on the second floor cross member 35 as described above. The outer fastening member 133 is a member for fastening the battery cross member 131 to the outer fastening bracket 141. The outer fastening member 133 has a lower portion 133a and an upper portion 133b.
The lower portion 133a has a bolt 151 projecting downward. The lower portion 133a is fastened to the battery cross member 131 by screwing the nut 152 to the bolt 151 of the lower portion 133a.

As shown in FIG. 26, the inner fastening unit 210 </ b> B includes an inner fastening bracket 142 and an inner fastening member 134.
The inner fastening bracket 142 is provided on the second floor cross member 35 as described above. The inner fastening member 134 is a member for fastening the battery cross member 131 to the inner fastening bracket 142. The inner fastening member 134 has a lower portion 134a and an upper portion 134b.
The lower portion 134a has a bolt 154 projecting downward. The lower portion 134a is fastened to the battery cross member 131 by screwing the nut 155 to the bolt 154 of the lower portion 134a.

As shown in FIG. 21, the battery 123 is accommodated in the battery case 121. In this state, the opening 127 of the battery case 121 is closed from above by the lid 122. The lid 122 has a lid wall portion 135, a lid top portion 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 135 is formed in the same manner as the case wall 124.
The upper end portion of the lid wall portion 135 is closed by the lid top portion 136, and the opening portion 138 is formed at the lower end portion. A lid flange 137 protrudes from the entire circumference of the opening 138 of the lid wall 135 to the outside of the lid 122.

By overlapping the lid flange 137 with the case flange 126 from above, the gap between the lid flange 137 and the case flange 126 is sealed by the seal member. Accordingly, the opening 127 of the battery case 121 is closed by the lid 122. The battery 123 is accommodated in the inside 129 of the battery pack 28. When the opening 127 of the battery case 121 is closed by the lid 122, the upper portion 133b of the outer fastening member 133 and the upper portion 134b of the inner fastening member 134 project upward from the opening of the lid top 136.

As shown in FIGS. 25 and 26, the upper portion 133b of the outer fastening member 133 has a bolt 165 projecting upward. The upper portion 133 b is fastened to the bottom portion 185 of the outer fastening bracket 141 by screwing the nut 166 to the bolt 165 of the upper portion 133 b.
Also, the upper portion 134 b of the inner fastening member 134 has a bolt 167 projecting upward. The upper portion 134 b is fastened to the bottom portion 202 of the inner fastening bracket 142 by screwing the nut 168 to the bolt 167 of the upper portion 134 b.
Thus, the battery pack 28 is fastened to the second floor cross member 35 via the outer fastening unit 210A and the inner fastening unit 210B. Thereby, the battery pack 28 in which the battery 123 (see FIG. 21) is accommodated is attached below the floor panel 16.

Here, the first seat rail 560 is attached to the first front fastening seat 23 (see FIG. 18) of the first floor cross member 34 and the first rear fastening seat 250 of the second floor cross member 35. . A second seat rail 570 is attached to the second front fastening seat 240 (see FIG. 18) of the first floor cross member 34 and the second rear fastening seat 26 of the second floor cross member 35.
Therefore, the outer fastening bracket 141 in the vicinity of the first rear fastening seat 250 is reinforced by the first seat rail 560. An inner fastening bracket 142 in the vicinity of the second rear fastening seat 26 is reinforced by a second seat rail 570. That is, the rigidity of the outer fastening bracket 141 and the inner fastening bracket 142 is enhanced. As a result, the battery pack 28 is reliably held, and the holding strength of the battery pack 28 is favorably maintained.

In this state, in the vicinity of the outer upper flange 188 of the outer fastening bracket 141, the first seat rail 560 of the passenger seat 32 is attached by the bolt 41 and the nut 42. The outer upper flange 188 is joined in a state of being held between the first joining portions 184.
Further, in the vicinity of the inner upper flange 206 of the inner fastening bracket 142, a second seat rail 570 of the passenger seat 32 is attached by a bolt 41 and a nut 42. The inner upper flange 206 is joined in a state of being held between the second joining portions 196.

As shown in FIG. 19, the tongue support portion 540 is connected to the second support bracket 770 of the second seat rail 570 by a bolt and a nut. The tongue 880 (see FIG. 17) of the seat belt 870 is locked to the buckle 850 of the tongue support portion 540. Thus, the occupant seated on the passenger seat 32 is suitably restrained by the seat belt 870 to the passenger seat 32.

Next, an example in which the tongue support portion 540 is supported by the lower body structure 12 when the impact load F40 is input from the front of the vehicle Ve will be described based on FIG.
As shown in FIG. 27, when an impact load F40 is input from the front of the vehicle Ve, the occupant 320 is held in a restrained state by the seat belt 870. At this time, a tensile load (load) F50 acts on the tongue support portion 540 via the seat belt 870.

Here, the bottom portion 202 of the inner fastening bracket 142 is fastened to the inner fastening member 134. Further, the inner upper flange 206 of the inner fastening bracket 142 is fixed in the vicinity of the second rear fastening seat 26 in the second floor cross member 35.
The inner upper flange 206 is sandwiched between the left end 173 a of the central member 173 and the inner end 172 b of the linear member 172. Thus, the inner upper flange 206 (i.e., the inner fastening bracket 142) is firmly supported between the left end 173a and the inner end 172b.

Further, a second rear fastening seat portion 26 of the second floor cross member 35 is formed in the central portion member 173. The tongue support portion 540 is connected to the second rear fastening seat portion 26 via the second seat rail 570.
Therefore, when the tensile load F50 acts on the tongue support portion 540, the tensile load F50 is reliably secured to the battery cross member 131 from the inner upper flange 206 through the inner fastening bracket 142 and the inner fastening member 134 (that is, the inner fastening unit 210B). Can tell.

That is, the support strength of the tongue support portion 540 (that is, the seat belt 870) can be secured. Therefore, the tensile load F50 can be reliably supported by the two members of the second floor cross member 35 and the battery cross member 131 using the inner fastening unit 210B. Thus, the occupant 320 can be suitably restrained by the seat belt 870.
Thus, the tensile load F50 is configured to be supported by the second floor cross member 35 and the battery cross member 131 of the two members. Thereby, the tongue support portion 540 (that is, the seat belt 870) can be supported without increasing the rigidity of the second floor cross member 35 more than necessary.

Furthermore, a second rear fastening seat 26 is formed on the center side in the vehicle width direction of the second floor cross member 35. A second seat rail 570 is attached near the second rear fastening seat 26. A first rear fastening seat 250 is formed at the vehicle width direction end of the second floor cross member 35. A first seat rail 560 is attached near the first rear fastening seat 250.
Therefore, the rigidity of the second floor cross member 35 is sufficiently ensured by the first seat rail 560 and the second seat rail 570. That is, when the tensile load F50 acts on the tongue support portion 540, the tensile load F50 can be more reliably supported by the two members of the second floor cross member 35 and the battery cross member 131. Thereby, the support strength of the tongue support portion 540 (that is, the seat belt 870) can be well secured.

Also, a first seat rail 560 is attached to the first front fastening seat 23 (see FIG. 18) of the first floor cross member 34 and the first rear fastening seat 250 of the second floor cross member 35. . A second seat rail 570 is attached to the second front fastening seat 240 (see FIG. 18) of the first floor cross member 34 and the second rear fastening seat 26 of the second floor cross member 35.
Therefore, the rigidity of the first floor cross member 34 and the second floor cross member 35 is sufficiently ensured by the first seat rail 560 and the second seat rail 570.
As a result, when the tensile load F50 acts on the tongue support portion 540, the tensile load F50 can be more reliably supported by the two members of the second floor cross member 35 and the battery cross member 131. That is, the support strength of the tongue support portion 540 (that is, the seat belt 870) can be satisfactorily secured.

Thus, the tensile load F50 is configured to be supported by the two members of the second floor cross member 35 and the battery cross member 131. Furthermore, the support strength of the tongue support portion 540 (that is, the seat belt 870) is configured to be favorably secured. As a result, the tongue support portion 540 (i.e., the seat belt 870) can be supported better without increasing the rigidity of the second floor cross member 35 more than necessary.

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

Moreover, in the said 2nd embodiment, although the battery cross member 131 was illustrated as an under-floor cross member, it does not limit to this. As another example, it is also possible to apply to other cross members arranged under the floor panel 16.

Furthermore, in the second embodiment, the first seat rail 560 and the second seat rail 570 are illustrated as the pair of seat support portions, but the present invention is not limited thereto. It is also possible to apply to the member which supports in the state which fixed a sheet | seat, for example as another sheet | seat support part.

Moreover, although the example which connected the battery cross member 131 to the 2nd floor cross member 35 was demonstrated in said 2nd embodiment, it does not restrict to this. As another example, it is also possible to connect the battery cross member 131 to the second floor cross member 35 and to connect the battery cross member to the first floor cross member 34 as well.

A third embodiment of the present invention will be described based on 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 of the vehicle.
As shown in FIG. 28 and FIG. 29, the vehicle body 10 is provided with a vehicle body lower structure 12 that constitutes the lower part of the vehicle body 10. The lower body 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, an inner bulkhead unit 19 on the left, and an outer bulk on the right 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 are provided.

Further, the lower body structure 12 includes a battery pack (under-floor mounting component (that is, in-vehicle component)) 28 (see FIG. 31), a battery pack frame (mounting component frame) 29 (see FIG. And a passenger seat 32.
In addition, since the vehicle body lower part structure 12 is comprised by the substantially left-right symmetrical member, hereafter, each structural member on the left side is demonstrated and description of each structural member on the right side is abbreviate | omitted.

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

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 longitudinal direction of the vehicle body, and also function as seat cross members. 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 by a fastening member such as a bolt 37 or a nut. For example, a passenger sheet 32 is attached to the left half of the first floor cross member 34 and the second floor cross member 35 by fastening members such as bolts 41 and nuts 42 (see FIG. 31). In addition, a rear seat 43 is provided on the third floor cross member 36.

members

The left outer bulkhead unit 18 includes a first outer bulkhead 51, a second outer bulkhead 52, and a third outer bulkhead 53.
The first outer bulkhead 51 is disposed on an extension of the first floor cross member 34. The second outer bulkhead 52 is disposed on an extension of the second floor cross member 35. The third outer bulkhead 53 is disposed on the extension 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, and in the following, the second outer bulkhead 52 will be described in detail as an "outer bulkhead 52", Detailed description of the third

outer bulkheads

51 and 53 is omitted.

As shown in FIG. 30, the left inner bulkhead unit 19 includes a first inner bulkhead 55, a second inner bulkhead 56, and a third inner bulkhead 57.
The first inner bulkhead 55 is disposed on the extension of the first floor cross member 34. The second inner bulkhead 56 is disposed on the extension of the second floor cross member 35. The third inner bulkhead 57 is disposed on the extension 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, and in the following, the second inner bulkhead 56 will be described in detail as the “inner bulkhead 56,” Detailed description of the third

inner bulkheads

55 and 57 is omitted.

Referring back to FIG. 29, the left gusset unit 24 includes a first gusset 61, a second gusset 62, and a third gusset 63.
The first gusset 61 is disposed below the inclined portion 99 on the left end side of the first floor cross member 34. The second gusset 62 is disposed below the inclined portion 107 (see also FIG. 31) of the second floor cross member 35 on the left end side. The third gusset 63 is disposed 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, and hereinafter, the second gusset 62 will be described in detail as "the gusset 62". Omit.

As shown in FIGS. 31 and 32, 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 outwardly bulging portion 71, an upper flange 72, and a lower flange 73. The outer bulging portion 71 is bulging 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.

upper flanges

lower flanges

73 and 78, whereby the stiffener 67 is disposed vertically.
An outer space 88 is formed between the side sill outer 65 and the stiffener 67. In addition, an inner space 89 is formed between the side sill inner 66 and the stiffener 67.

As shown in FIGS. 33 and 34, the outer bulkhead 52 is disposed 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 joining 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. A 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 (the end away from the stiffener 67) of the side wall 84 is closed by the bottom 85. The bottom 85 is formed in a rectangular shape. An opening 87 (see also FIG. 32) is formed in a rectangular shape at the other end (end on the stiffener 67 side) of the side wall 84. A joint flange 86 is formed at the other end of the side wall 84.

That is, the joining 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. A front joint flange 93a, a rear joint flange 93b, an upper joint flange 93c, and a lower joint flange 93d that constitute the joint flange 93 are disposed in contact with the inner surface 67d of the stiffener 67.
The inner bulkhead 56 is formed in a box shape having a polygonal cross section (rectangular cross section in the third embodiment) in which the opening 94 is opened on the stiffener 67 side in a rectangular shape having the same shape as the opening 87 of the outer bulkhead 52 It is done.

With the joining flange 86 of the outer bulkhead 52 being in contact with the outer surface 67 c of the stiffener 67 and the joining flange 93 of the inner bulkhead 56 being in contact with the inner surface 67 d of the stiffener 67 It is superimposed through. The overlapping joining flange 86 and the joining flange 93 are joined to each other via stiffeners 67.
Thus, 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 to overlap the second floor cross member 35 in the vehicle width direction.

As shown in FIGS. 29 and 32, the outer bulkhead 52 and the inner bulkhead 56 are provided to overlap the second 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. Furthermore, the load F2 that has passed through the outer bulkhead 52 and the inner bulkhead 56 can be well supported by the second floor cross member 35.
As described above, it is possible to absorb the impact energy by crushing the outer bulkhead 52 and the inner bulkhead 56 with the impact load F1 input from the side of the vehicle Ve.

Returning to FIG. 34, 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 holes 96 in the stiffener 67, when the inside of the left side sill 14 is electrodeposited, the electrodeposition paint can be well guided to the inside of the left side sill 14 using the holes 96. Thereby, the electrodeposition paint can be easily attached to the inside of the left side sill 14.
Further, by forming the hole 96 in the stiffener 67, the weight of the stiffener 67 can be reduced, and the weight of the vehicle body 10 can be reduced.

As shown in FIGS. 31 and 33, the left side portion 16c of the floor panel 16 is attached to the upper portion (upper surface) 82 of the inner bulged portion 76 of the side sill inner 66. An upper portion 82 of the inner bulging portion 76 is a portion to be an upper portion of the left side sill 14. Hereinafter, the upper portion of the left side sill 14 is referred to as a “side sill upper portion 82”.
The floor panel 16 is formed flat. Thus, the floor panel 16 is disposed 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 getting in and out of the occupant, and it is possible to ensure good getting in and out of the occupant.

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

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

As shown to FIG. 35, FIG. 36, the 2nd floor cross member 35 is formed in substantially left-right symmetry (also refer FIG. 29). Therefore, hereinafter, the left side of the second floor cross member 35 will be described in detail, and the description of the right side will be omitted. The second floor cross member 35 includes an end member 171, a straight portion member 172, and a central portion member 173 which are joined in order from the outside in the vehicle width direction toward the center.
The end member 171 is disposed on the left outside 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 from the inner end of the end member 171 inward in the vehicle width direction. The central member 173 extends inward in the vehicle width direction from the inner end of the linear member 172. The central member 173 is arranged to straddle the floor tunnel 192 of the floor panel 16.
In addition, the second floor cross member 35 includes an outer fastening bracket (fastening bracket) 141 and an inner fastening bracket (fastening bracket) 142.

As shown in FIG. 37, the end member 171 has an inclined portion 107 and a horizontal portion 175. The inclined portion 107 is disposed on the left side sill 14 side.
The inclined portion 107 has an upper inclined portion 108, a joint seat 177, and a bead 178.
The upper inclined portion 108 is a portion that forms the upper portion of the inclined portion 107.
The joint seat portion 177 extends horizontally outward from the outer end 108 a of the upper inclined portion 108 in the vehicle width direction and is joined to the side sill upper portion 82.

The bead 178 extends outward in the vehicle width direction from the portion 108 b in the middle of the upper inclined portion 108 to the outer edge of the joint seat 177. The bead 178 is formed to bulge upward. For example, a plurality of beads 178 are formed at intervals in the longitudinal direction of the vehicle body. In the third 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.

The horizontal portion 175 extends parallel to the floor panel 16 from the inner end of the inclined portion 107 inward in the vehicle width direction. The left side sheet attachment portion 181 (see FIG. 38) of the passenger seat 32 is attached to an upper portion 175 a of the horizontal portion 175 by a bolt 41 and a nut 42.
The end member 171 is formed in a relatively complicated shape by closing the outer end of the horizontal portion 175 with the inclined portion 107.

As shown in FIGS. 35 and 36, the inner end portion 171a of the end member 171 and the outer end portion 172a of the linear portion member 172 are joined in a state of being overlapped. By joining the inner end 171a of the end member 171 and the outer end 172a of the linear member 172, the first joint portion 184 is formed by the overlapped inner end 171a and the outer end 172a. ing. An outer fastening bracket 141 is joined to the first joint portion 184.

As shown in FIGS. 37 and 38, the outer fastening bracket 141 has a bottom portion 185, an outer leg portion (bulk head portion) 186, an inner leg portion (bulk head portion) 187, and an outer upper flange (upper flange) 188. And an inner upper flange 189.
The bottom portion 185 is disposed along the floor panel 16 and is fastened to the upper portion 133 b of the outer fastening member 133 via the floor panel 16 by a bolt 165 and a nut 166. The bottom portion 185 forms a bolt insertion portion 185 c together with the facing portion of the floor panel 16. The bolt insertion portion 185 c has a bolt insertion hole 185 a for inserting the bolt 165. The bolt insertion hole 185 a includes the floor through hole 39 a of the floor panel 16.
Lower flanges 185 b extend from the front and rear ends of the bottom portion 185 so as to be continuous with the bottom portion 185 forward and backward. The front and rear lower flanges 185 b are respectively joined to the floor panel 16.

The outer leg (bulk head) 186 is bent upward from the outer side of the bottom 185 and is raised to the upper portion 175 a of the horizontal portion 175 (the upper surface 171 c of the inner end 171 a of the end member 171). . From the inside portion of the bottom portion 185, the inner leg portion (bulk head portion) 187 is bent upward and is raised to the upper surface portion 172c of the linear portion member 172. The outer fastening bracket 141 is formed in a U-shaped cross section by the bottom portion 185, the outer leg portion 186 and the inner leg portion 187.

Referring also to FIG. 43, the bolt insertion hole 185a is larger in diameter (approximately twice) than the diameter of the bolt 165, and allows a horizontal displacement of the bolt 165. The nut 166 integrally forms a flange 166a having a diameter larger than the diameter of the bolt insertion hole 185a. The nut 166 is attached to and detached from the stud bolt (bolt 165) projecting into the second floor cross member 35 through the working hole 166 b formed in the second floor cross member 35. By integrally forming the flange 166a on the nut 166, the attaching and detaching operation of the nut 166 is facilitated as compared with the case where a washer separate from the nut 166 is used.

The outer upper flange 188 is bent from the upper end of the outer leg portion 186, and extends outward in the vehicle width direction along the outer surface (upper surface) of the upper surface portion 171c of the inner end portion 171a. The outer upper flange 188 is joined to the upper surface portion 171 c of the inner end portion 171 a and the upper surface portion 172 c of the outer end portion 172 a at the first joint portion 184. Thereby, since the upper part (member upper part 101) of the 2nd floor cross member 35 mutually spaced up and down and the floor panel 16 are connected via the outer leg part 186, the strength rigidity of the 2nd floor cross member 35 improves.

The outer upper flange 188 is joined to the first joint portion 184 in a state of being held between the upper surface portion 171c of the inner end portion 171a of the end member 171 and the upper surface portion 172c of the outer end portion 172a of the linear portion member 172 It is done. In other words, the inner end 171 a and the outer end 172 a are joined via the outer upper flange 188.

The bottom portion 185 of the outer fastening bracket 141 is fastened to the upper portion 133 b of the outer fastening member 133 with a bolt 165 and a nut 166 via the floor panel 16. The outer fastening bracket 141 uses a high strength member to support the battery pack 28. Thus, the first joint portion 184 is reinforced by the outer upper flange 188.

An inner upper flange 189 is bent from the upper end of the inner leg portion 187 and extends inward in the vehicle width direction along the inner surface (lower surface) of the upper surface portion 172 c of the straight portion member 172. The inner upper flange 189 is joined to the lower surface of the straight portion member 172.

As shown in FIGS. 36 and 39, the central member 173 is disposed so as to cross (orthogonal) the floor tunnel 192 of the floor panel 16 and is mounted so as to straddle the floor tunnel 192 laterally. The central member 173 has an upper portion 173b extending in the vehicle width direction and a raised portion 194 raised at the center in the vehicle width direction. The right side sheet attachment portion 182 of the passenger seat 32 (see FIG. 38) is attached to an upper portion 173 b of the central member 173 by a bolt 41 and a nut 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 173 a of the central member 173 and the inner end portion 172 b of the linear portion member 172 are joined in a state where they are superimposed on each other. The left end 173a of the central member 173 and the inner end 172b of the linear member 172 are joined to form a second joint 196 between the left end 173a and the inner end 172b. An inner fastening bracket 142 is joined to the second joint portion 196.

Similar to the outer fastening bracket 141, the inner fastening bracket 142 has a bottom 202, an outer leg (bulk head) 203, an inner leg (bulk head) 204, an outer upper flange 205, and an inner upper flange Upper flange) 206, and
The bottom portion 202 is disposed along the floor panel 16 and is fastened to the upper portion 133 b of the outer fastening member 133 via the floor panel 16 by a bolt 167 and a nut 168. The bottom portion 202 forms a bolt insertion portion 202 c together with the facing portion of the floor panel 16. The bolt insertion portion 202 c has a bolt insertion hole 202 a for inserting the bolt 167. The bolt insertion hole 202 a includes the floor through hole 39 b of the floor panel 16.
Lower flanges 202b extend from the front and rear ends of the bottom 202 so as to be continuous with the bottom 202 toward the front and the rear. The front and rear lower flanges 202 b are respectively joined to the floor panel 16.

The outer leg portion 203 (bulk head portion) is bent upward from the outer side portion of the bottom portion 202 and is raised to the upper surface portion 172 c of the inner end portion 172 b of the linear portion member 172. The inner leg portion (bulk head portion) 204 is bent upward from the inner portion of the bottom portion 202 and raised to the upper portion 173 b of the central portion member 173 (the upper surface portion 173 c of the left end portion 173 a of the central portion member 173) There is. The inner fastening bracket 142 is formed to have a U-shaped cross section by the bottom portion 202, the outer leg portion 203 and the inner leg portion 204.

Similar to the bolt insertion hole 185a shown in FIG. 43, the bolt insertion hole 202a is larger in diameter (approximately twice) than the diameter of the bolt 167, and allows a horizontal displacement of the bolt 167. The nut 168 integrally forms a flange 168a having a diameter larger than the diameter of the bolt insertion hole 202a. The nut 168 is attached to and detached from a stud bolt (bolt 167) projecting into the second floor cross member 35 through a working hole 168b formed in the second floor cross member 35. By integrally forming the flange 168a on the nut 168, the attaching and detaching operation of the nut 168 is facilitated as compared with the case where a washer separate from the nut 168 is used.

The inner upper flange 206 is bent from the upper end of the inner leg portion 204 and extends inward in the vehicle width direction along the outer surface (upper surface) of the upper surface portion 173 c of the central member 173. The inner upper flange 206 is joined to the upper surface portion 173 c of the central member 173 and the upper surface portion 172 c of the inner end portion 172 b at the second joint portion 196. Thereby, since the upper portion (member upper portion 101) of the second floor cross member 35 and the floor panel 16 which are vertically separated from each other are connected via the inner leg portion 204, the strength and rigidity of the second floor cross member 35 is increased. improves.

The inner upper flange 206 is joined to the second joint 196 in a state of being held between the upper surface 173 c of the left end 173 a of the central member 173 and the upper surface 172 c of the inner end 172 b of the linear member 172. It is done. In other words, the left end 173 a and the inner end 172 b are joined via the inner upper flange 206.

The bottom portion 202 of the inner fastening bracket 142 is fastened to the upper portion 133 b of the outer fastening member 133 by a bolt 167 and a nut 168 via the floor panel 16. The inner fastening bracket 142 uses a high strength member to support the battery pack 28. Thus, the second joint portion 196 is reinforced by the inner upper flange 206.

The outer upper flange 205 is bent from the upper end of the outer leg portion 203 and extends outward along the inner surface (lower surface) of the upper surface portion 172 c of the straight portion member 172. The outer upper flange 205 is joined to the lower surface of the straight portion member 172.

Therefore, the second floor cross member 35 can manufacture, for example, the end member 171 or the central member 173 having a complicated shape by draw forming, and can manufacture the linear member 172 having a simple shape by bend forming. By dividing the second floor cross member 35 into three parts, the end member 171 and the central member 173 of the draw molding can be made smaller, and the straight portion member 172 can be made by bending to reduce the manufacturing cost of the second floor cross member 35 it can.

In addition, it is possible to optimize the collision mode by making the strengths of the end member 171, the linear portion member 172, and the central portion member 173 different. In this case, a device for securing the strength of the first joint portion 184 (see FIG. 38) of the end member 171 and the linear portion member 172 and the second joint portion 196 of the linear portion member 172 and the central portion member 173 is required. Be 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. As the outer fastening bracket 141 and the inner fastening bracket 142, high strength members are used to support under floor mounting components such as the battery pack 28.

Therefore, the outer fastening bracket 141 is joined to the first joint portion 184 and the inner fastening bracket 142 is joined to the second joint portion 196, whereby the first joint portion 184 is reinforced by the outer fastening bracket 141, and the second joint is formed. The part 196 is reinforced by the inner fastening bracket 142. Thereby, the load transfer performance of the second floor cross member 35 in the vehicle width direction can be secured, and the second floor cross member 35 can support the impact load F1 input from the side of the vehicle Ve favorably.

Furthermore, by providing the second floor cross member 35 on the upper surface 16 a of the floor panel 16, the floor cross member can be removed from below the floor panel 16. Thus, the space under the floor panel 16 can be increased. Thereby, the capacity of the under-floor mounting component such as 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 range of the vehicle Ve can be increased.

Referring back to FIGS. 31 and 32, a battery pack 28 is provided between the left side sill 14 and the right side sill 15 (see FIG. 29) and below the floor panel 16. The battery pack 28 includes a battery case 121 and a lid (waterproof cover) 122. The battery case 121 has a case wall 124, a case bottom 125, and a case flange 126.
The case wall portion 124 has a front wall, a rear wall, a left side wall 124 a 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 124 a, and the right side wall.

The lower end portion of the case wall portion 124 is closed by the case bottom portion 125, and an opening portion 127 is formed at the upper end portion. A case flange 126 projects from the entire circumference of the opening 127 of the case wall 124 to the outside of the battery case 121.
A battery cross member (second cross member) 131 is provided inside the battery case 121 (that is, the inside 129 of the battery pack 28). The battery cross member 131 extends in the vehicle width direction at the inside 129 of the battery pack 28.
The battery cross member 131 has a flange 131a at the left end. The flange 131 a is joined to the left side wall 124 a of the case wall 124.
Referring also to FIG. 42, lower mounting portions 133a of a plurality of fastening members 133 are attached to the battery cross member 131 at intervals in the vehicle width direction by bolts and nuts. The battery 123 is accommodated in the battery case 121.

The protruded upper portion 133 b is fastened to the outer fastening bracket 141 of the floor cross member 35 by a bolt 165 and a nut 166. The projecting upper portion 133 b is fastened to the inner fastening bracket 142 of the floor cross member 35 with a bolt 167 and a nut 168. Thus, 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 the plurality of fastening members 133 and the like. Further, the floor cross member 35 and the battery cross member 131 are integrally connected via a plurality of fastening members 133 and the like.

As shown in FIGS. 32 and 40, the battery pack 28 is disposed inward of 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 124 a (the outer periphery of the battery pack 28) of the case wall 124. The battery pack frame 29 is formed to have 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 a lower portion (lower surface) 83 of the inner bulging portion 76. The lower portion 83 of the inner bulging portion 76 is a portion that is the lower portion of the left side sill 14. Hereinafter, the lower portion of the left side sill 14 will be referred to as "side sill lower portion 83 (lower surface portion)".
The frame main body 144 is raised from the fixing portion 143 toward the side sill inner wall 81 and is disposed to face the inner bulkhead 56 via the side sill inner wall 81.

The frame body 144 has an inner wall 146, an outer wall 147, a top 148, a bottom 149, and a lower flange 151. A frame body 144 is formed in a rectangular frame shape in cross section by the inner wall 146, the outer wall 147, the top 148, and the bottom 149.
The inner wall 146 of the frame body 144 is joined along the left side wall 124 a of the case wall 124. Furthermore, the inner wall 146 is also joined to the flange 131a of the battery cross member 131 via the left side wall 124a. That is, the frame main 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. A bulkhead 152 is attached to the inside of the frame body 144. The bulkhead 152 is provided to close the cross section of the frame main body 144, and upper and lower outer peripheral flanges 152a are joined to the inner wall 146, the outer wall 147, the top 148 and the bottom 149, respectively.

Thus, the fixing portion 143 is attached to the side sill lower portion 83, and the frame main body 144 of the battery pack frame 29 is raised toward the side sill inner wall 81. The frame body 144 is opposed to the inner bulkhead 56 via the side sill inner wall 81. Further, the frame main body 144 is joined to the flange 131 a of the battery cross member 131 via the inner wall 146 and the left side wall 124 a. As a result, the battery pack 28 can be firmly supported by the side sill 14.

The battery pack 28 includes a lid 122 which is also a waterproof cover between the battery pack 28 and the floor panel 16. The lid 122 is formed with through

holes

122a and 122b through which the

stud bolts

165 and 167 are respectively inserted.
Referring to FIGS. 43 and 44 together, the through

holes

122a and 122b are provided with sealing members 128 for watertightly sealing around the corresponding

stud bolts

165 and 167, respectively. The seal member 128 is made of, for example, an elastic member such as synthetic rubber, and has a cylindrical shape through which the

corresponding stud bolts

165 and 167 are inserted. An outer peripheral groove 128a is formed on the outer periphery of the seal member 128. The outer peripheral groove 128a allows the peripheral edge portions of the corresponding through

holes

122a and 122b to be inserted. The seal member 128 is sandwiched between the floor panel 16 and the lid 122 in a compressed state.

The sealing member 128 can suppress water intrusion from the through

holes

122 a and 122 b through which the

stud bolts

165 and 167 in the lid 122 of the battery pack 28 are inserted. Since the seal member 128 is sandwiched between the floor panel 16 and the lid 122 in a compressed state, it is possible to obtain the vibration and soundproof effect of the floor panel 16 and the lid 122.

The floor panel 16 has floor through

holes

39a and 39b facing the through

holes

122a and 122b and forming a part of the

bolt insertion holes

185a and 202a, and the floor through

holes

39a and 39b in plan view. And a drain groove 39c extending to the rear outside of 122). The rear end of the drainage groove 39c reaches a drainage hole 39d located rearward of the battery pack 28 (lid 122). Thus, even if water intrudes from the floor through

holes

39a and 39b into the compartment, the water can be drained from the drainage groove 39c to the outside of the battery pack 28.

As described above, the vehicle body lower structure 12 according to the third embodiment of the present invention includes the floor panel 16 provided at the lower part of the vehicle body and having the floor cross member 35 and the battery cross member mounted below the floor panel 16 A battery pack 28 having 131,

stud bolts

165 and 167 fixed in advance to one side (battery cross member 131) of floor cross member 35 and battery cross member 131 and projecting to the other side, floor cross member 35 and battery cross The

bolt insertion portions

185c and 202c provided on the other side (floor cross member 35) of the member 131 and forming

bolt insertion holes

185a and 202a having a diameter larger than the diameter of the

stud bolts

165 and 167, and bolt

insertion holes

185a and 202a Through the

stud bolts

165 and 167 Ri with its dependent includes a

nut

166, 168 for fastening the floor cross member 35 and the battery cross member 131 cooperates with

stud bolt

165, 167, a.

According to this configuration, the vehicle body rigidity can be enhanced by fastening the floor cross member 35 and the battery cross member 131 mounted under the floor. Since the diameters of the

bolt insertion holes

185a and 202a are set larger than the diameters of the

stud bolts

165 and 167, the battery pack 28 can be easily assembled even if an assembly error (a tolerance) or the like occurs. By using the

stud bolts

165 and 167 as the fastening members, the

stud bolts

165 and 167 can be inserted into the bolt insertion holes 185 a and 202 a simultaneously with the operation of setting the battery pack 28 in a fixed position under the floor panel 16. Since the

bolt insertion holes

185a and 202a have larger diameters than the

stud bolts

165 and 167, the

stud bolts

165 and 167 are used after absorbing errors such as positional deviations of the

stud bolts

165 and 167 and the

bolt insertion holes

185a and 202a. It can be inserted into the

bolt insertion holes

185a and 202a.

Further, the

joint flanges

86 and 93 of the outer bulkhead 52 and the inner bulkhead 56 are joined to each other via stiffeners 67. Thus, the box-like shape of the outer bulkhead 52 is restrained by the joining flange 86. Further, the box-like shape of the inner bulkhead 56 is restrained by the joining flange 93.
Thus, when the impact load F1 is input from the side of the vehicle Ve, the impact load F1 is transmitted to the entire region (that is, the entire circumference) of the side wall 84 of the outer bulkhead 52. Further, the impact load F1 is transmitted to the entire region (that is, the entire circumference) of the side wall 91 of the inner bulkhead 56. As a result, 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 can be buckled with the impact load F1, and the impact energy can be absorbed.

Here, the battery pack 28 is mounted inside the left side sill 14 in the vehicle width direction.
In this case, the outer bulkhead 52 and the inner bulkhead 56 absorb the impact load F1 input from the side of the vehicle Ve, thereby protecting the battery 123 in the battery pack 28 from the impact load F1.

In addition, the outer bulkhead 52 is disposed outside the stiffener 67 in the vehicle width direction, and the inner bulkhead 56 is disposed inside the stiffener 67 in the vehicle width direction. That is, the outer bulkhead 52 and the inner bulkhead 56 are arranged side by side in the vehicle width direction. Therefore, the outer bulkhead 52 and the inner bulkhead 56 can be provided inside the left side sill 14 without increasing the height of the left side sill 14.
Thus, the height of the left side sill 14 can be reduced, and the passenger can get in and out well without the left side sill 14 being in the way when getting on or off the passenger.

Next, an example of protecting the battery 123 by the lower vehicle body structure 12 when an impact load F6 is input from the side of the vehicle Ve will be described based on FIG.
As shown in FIG. 41, an impact load F6 is input to the left side sill 14 from the side of the vehicle Ve. The outer bulging portion 71 of the side sill outer 65 of the left side sill 14 is deformed inward in the vehicle width direction by the impact load F6 input to the left side sill 14. The outer bulging portion 71 is deformed and abuts on the bottom 85 of the outer bulkhead 52.

Bonding flanges

The technical scope of the present invention is not limited to the third embodiment described above, and various modifications can be made without departing from the spirit of the present invention.
For example, in the third embodiment, the battery pack 28 is illustrated as an under-floor mounting component (that is, an on-vehicle component), but the present invention is not limited to this. As another example, it is also possible to use a fuel tank or the like as an underfloor mounting component.
For example, a stud bolt may be fixed to the floor cross member, and a bolt insertion portion may be provided in the second cross member of the under-floor mounting component.

10 body 10a left side portion 10b right side portion 12 lower body structure 14 left side sill (side sill)
15 Right side sill (side sill)
16 floor panel 16a upper surface of floor panel 16b lower surface of floor panel 23 first front fastening seat (fastening seat)
26 Second rear fastening seat (fastening seat)
28 Battery Pack (mounted under the floor)
29 Battery pack frame (mounted parts frame)
31 Driver sheet (sheet)
32 passenger seat (sheet)
34 1st floor cross member (floor cross member)
35 2nd floor cross member (floor cross member)
36 3rd floor cross member (floor cross member)
39a, 39b floor through hole 39c drainage groove 51 first external bulkhead (bulkhead)
52 2nd outside bulkhead (bulkhead)
53 Third Bulkhead (Bulkhead)
55 1st inner bulkhead (bulkhead)
56 Second inner bulkhead (bulkhead)
57 3rd inner bulkhead (bulkhead)
61 1st gusset (gusset)
62 2nd gusset (gusset)
63 3rd gusset (gusset)
81 Side sill inner wall (side sill inner wall)
81a The part facing the bulkhead 82 Upper side of side sill (upper side of side sill)
83 Lower side sill (bottom)
88 Outside space (inside of side sill)
89 Inner space (inside of side sill)
101 member top (top)
102 member front wall portion 103 member rear wall portion 107 inclined portion 108 upper inclined portion 111 gusset inclined portion 112 gusset front wall portion 113 gusset rear wall portion 122 lid (waterproof cover)
122a, 122b through hole 123 battery 128 seal member 129 inside of battery pack (inside of under-floor mounting parts)
131 Battery Cross Member (Under Floor Cross Member, Second Cross Member)
133 Outer fastening member (fastening member)
134 Internal fastening member (fastening member)
141 Outer fastening bracket (fastening bracket)
142 Inner fastening bracket (fastening bracket)
165,167 bolt (stud bolt)
166, 168

Nut

166a, 168a Flange 166b,

168b Work hole

171, 301

End member

171c, 172c, 173c

Upper surface portion

172, 302

Straight portion member

173, 303 Central portion member 177 Joint seat portion 178

Bead

184, 197 First

joint Part

185, 202

Bottom part

185a, 202a

Bolt insertion hole

185b, 202b

Lower flange

185c, 202c

Bolt insertion part

186, 203 Outer leg part (bulk head part)
187, 204 inner leg (bulk head)
188, 205, 307 Outer

upper flange

189, 206, 308 inner

upper flange

196, 198 second joint portion 210 (210A) outer fastening unit (fastening unit)
210 (210B) Inner fastening unit (Fastening unit)
240 Second front fastening seat (fastening seat)
250 first rear fastening seat (fastening seat)
530 sheet attachment portion 540 tongue support portion (belt support portion)
560 First Seat Rail (First Seat Support)
570 Second seat rail (second seat support)
870 Seat belt 880 Tongue F2, F50 Tension load (load)
Ve vehicle

Claims

An undercarriage comprising a floor panel disposed between side sills on both sides of the vehicle and mounted on top of each side sill,
A floor cross member provided on the upper surface of the floor panel, extending in the vehicle width direction, being bridged between the side sills, and having a member upper portion positioned above the upper portion of the side sills;
A gusset which is disposed below the floor cross member and is constructed on the inner wall of the side sill and the lower surface of the floor panel and extends downward from the lower surface of the floor panel to the inner wall of the side sill in the vehicle width direction; Equipped with
The upper portion of the member has an upper inclined portion extending downward toward the outer side in the vehicle width direction to the upper portion of the side sill.
Underbody structure characterized by
An underfloor cross member disposed below the floor cross member and attached to an under floor mounting component,
A fastening unit for attaching the underfloor cross member to the floor cross member;
And a seat attached to the floor cross member.
The sheet is
A sheet attachment portion capable of transmitting a load to the fastening unit by being attached in the vicinity of the fastening unit of the floor cross member;
And a belt support unit connected to the seat attachment unit and supporting the seat belt.
The lower vehicle body structure according to claim 1, wherein
A stud bolt provided on one of the floor cross member and the second cross member and protruding to the other side;
A bolt insertion portion provided on the other of the floor cross member and the second cross member and forming a bolt insertion hole having a diameter larger than the diameter of the stud bolt;
The nut further includes a nut attached to the stud bolt penetrating the bolt insertion hole and fastening the floor cross member and the second cross member in cooperation with the stud bolt.
The underbody structure of a vehicle according to claim 2, characterized in that.
The floor cross member is
A joint seat extending from the upper inclined portion toward the outer side in the vehicle width direction and joined to an upper portion of the side sill;
An upwardly protruding bead extending in the vehicle width direction from the upper inclined portion to the joint seat;
The lower vehicle body structure according to claim 1, wherein
The floor cross member is
The upper inclined portion, a member front wall extending from the front side of the upper inclined portion to the floor panel, and a member rear wall extending from the rear side of the upper inclined portion to the floor panel are formed in a U shape.
The gusset is
Gusset slope extending downward from the lower surface of the floor panel to the inner wall of the side sill and extending downward from the bottom of the floor panel, gusset front wall extending from the front side of the gusset to the floor panel, and front gusset slope A U-shaped gusset back wall extending from the rear edge of the part to the floor panel,
The floor cross member and the gusset are joined with the floor panel interposed therebetween.
The lower vehicle body structure according to claim 1 or 4, characterized in that:
The apparatus further comprises a bulkhead provided inside the side sill and facing the inner wall of the side sill,
The gusset is attached to a portion of the inner wall of the side sill that faces the bulkhead.
The lower vehicle body structure according to any one of claims 1, 4, and 5, characterized in that:
The floor cross members are provided at least in a pair at intervals in the longitudinal direction of the vehicle body,
A sheet is attached to the pair of floor cross members
The vehicle body lower structure according to any one of claims 1, 4, 5, and 6.
The floor cross member is
The end member, the straight portion member, and the center portion member joined in order from the outer side to the center in the vehicle width direction;
The first joint portion between the end member and the linear portion member and the second joint portion between the linear portion member and the central portion member are connected to an underfloor mounted component disposed below the floor panel. Joined to the fastening bracket,
An underbody structure according to any one of claims 1, 4, 5, 6, 7, characterized in that.
The fastening unit is
A fastening bracket provided on the floor cross member;
A fastening member for fastening the underfloor cross member to the fastening bracket;
The fastening bracket is
A bottom portion disposed along the floor panel and fastened to the fastening member;
When launched from the bottom,
The load is applied to the fastening seat portion by extending along the floor cross member from the upper end of the bulkhead portion and fixing the sheet mounting portion of the floor cross member in the vicinity of the fastening seat portion fastened. And an upper flange capable of transmitting
The underbody structure of a vehicle according to claim 2, characterized in that.
The floor cross member includes an end member, a straight portion member, and a center portion member joined in order from the outside in the vehicle width direction toward the center,
The first joint portion between the end member and the linear portion member, and the second joint portion between the linear portion member and the central portion member are connected to the under-floor mounting component disposed below the floor panel. Joined to the fastening bracket
An underbody structure according to claim 9, characterized in that.
The fastening seat of the floor cross member is formed on the central member;
The upper flange is held between the central member and the straight member.
An underbody structure according to claim 10, characterized in that.
The fastening seat portion is formed on a center side in the vehicle width direction of the floor cross member and an end side in the vehicle width direction.
The seat attachment portion includes a pair of seat support portions provided at intervals in the vehicle width direction,
One of the pair of seat support portions is attached in the vicinity of the fastening member on the center side so as to reinforce the fastening member on the center side in the vehicle width direction,
The other of the pair of seat support portions is attached in the vicinity of the fastening member on the end portion side so as to reinforce the fastening member on the vehicle width direction end portion side.
The vehicle body lower structure according to any one of claims 9 to 11, characterized in that
The seat support portion is a seat rail that extends in the longitudinal direction of the vehicle body so as to slide and move the seat in the longitudinal direction of the vehicle body,
The floor cross members are disposed at least in the longitudinal direction of the vehicle body,
The seat rails are attached to the fastening seats of the pair of floor cross members.
The underbody structure of a vehicle according to claim 12, characterized in that.
The floor cross member includes an end member, a straight portion member, and a center portion member joined in order from the outside in the vehicle width direction toward the center,
The first joint between the end member and the linear member and the second joint between the linear member and the central member are joined to a fastening bracket to which the underfloor mounting component is coupled.
The vehicle body lower structure according to claim 3, characterized in that:
The nut is integrally formed with a flange having a diameter larger than the diameter of the bolt insertion hole, and is attached to the stud bolt through a working hole formed in the floor cross member or the second cross member.
The lower vehicle body structure according to claim 3 or 14, characterized in that:
The fastening bracket is
A bottom portion formed in a plate shape along the floor panel and in which the bolt insertion hole is formed;
A lower flange extending continuously in a first direction from an end of the bottom in a first direction;
A bulkhead bent from an end in a second direction intersecting the first direction of the bottom and extending toward the top of the floor cross member;
An upper flange bent and extended along a top portion of the floor cross member from a tip end of the bulkhead portion;
Have
The upper flange is fixed to an upper portion of the floor cross member, and the lower flange is fixed to the floor panel.
The underbody structure of a car according to claim 14, characterized in that.
The upper flange is held between at least one of the first joint portion and the second joint portion in the thickness direction between upper surface portions of adjacent members in the vehicle width direction.
The underbody structure of a car according to claim 16, characterized in that.
The underfloor mounting part comprises a waterproof cover between the floor panel and
The waterproof cover is formed with a through hole through which the stud bolt is inserted.
In the through hole, a seal member for watertightly closing the periphery of the stud bolt is attached.
The sealing member is sandwiched in a compressed state between the floor panel and the waterproof cover.
An underbody structure according to any one of claims 3, 14, 15, 16, 17 characterized in that.
The floor panel is formed with a floor through hole forming the bolt insertion hole, and a drainage groove extending from the floor through hole to the outside of the under-floor mounting component in a plan view.
An underbody structure according to any one of claims 3, 14, 15, 16, 17, 18 characterized in that.
The vehicle further comprises a side sill for supporting the outside in the vehicle width direction of the floor panel,
The underfloor mounting component comprises a mounting component frame supported on the lower surface of the side sill,
The second cross member is fixed to the mounting component frame.
The lower vehicle body structure according to any one of claims 3, 14, 15, 16, 17, 18, 19.