JP2007216903A - Lower vehicle body structure for automobile - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lower part vehicle body structure for an automobile capable of enhancing amenity in a cabin by enlarging a cabin space by lowering the height of a vehicle body floor and by reducing the lateral member as much as possible, while enhancing side collision performance by installing a lateral member or the like on a floor panel, in the lower vehicle body structure for the automobile. <P>SOLUTION: The lower vehicle body structure for the automobile is constituted such that side collision load is dispersed even to No.4 closed cross section 50 by connecting No.3 cross members 4, 4 and a kick up part 12 by providing vertical members 7, 7 extending in a vehicle longitudinal direction. Thereby, the No.3 closed cross section 40 and the No.4 closed cross section 50 cooperate to support the side collision load, thereby the side collision performance is enhanced. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a lower body structure of an automobile, and more particularly to an automobile lower body structure provided with a vehicle body floor having a crossing bar, a kick-up portion and the like extending in the vehicle width direction.

  Conventionally, various loads are applied to the lower car body structure of an automobile, especially the car body floor, so the body frame and side sills that extend in the vehicle front-rear direction and the cross member that extends in the car width direction are joined to the floor rigidity. Is increasing.

  In addition, an exhaust pipe, a fuel tank, and a suspension cross member must be installed below the vehicle body floor, so a tunnel portion extending in the vehicle front-rear direction and a kick-up portion protruding upward at the vehicle rear portion are provided. It is also known to form.

By the way, since the upper space is an occupant's living space, there is a demand for reducing the amount of protrusion to the vehicle interior side (upper side) as much as possible. In order to meet this requirement, in Patent Document 1 below, the tunnel portion is eliminated and the vehicle body floor is formed flat. However, since the vehicle body rigidity may decrease and the side impact performance may decrease, the floor rigidity can be increased while the vehicle body floor is flattened by joining the horizontal member and the vertical member to the lower surface of the vehicle body floor. Yes.
Japanese Patent Laid-Open No. 10-264863

  By the way, in recent years, there has been a demand for improvement in the collision safety performance of the vehicle body, and there has been a demand for improving the side collision performance corresponding to the impact from the side of the vehicle. In particular, in the vehicle body floor, it is required to improve the side collision performance by suppressing the penetration of the side sill into the vehicle body inward side.

  As described in Patent Document 1, the lateral member is joined to the lower surface of the vehicle body floor. When the side collision performance is improved, the side sill and the lateral member are offset in the vertical direction. As a result, the height of the vehicle body floor must be set higher.

  Therefore, in order to reduce the height position of the vehicle body floor while improving the side collision performance, a configuration in which the lateral member is joined to the upper surface of the vehicle body floor and installed at a height position that substantially coincides with the side sills in the vertical direction is considered. It is done.

  However, the side impact load acts when the side sill extending in the vehicle front-rear direction entirely penetrates into the inner side of the vehicle body, so even if only one lateral member is installed on the vehicle body floor, it cannot be sufficiently supported. . Then, next, it can be considered that the side sill is supported in cooperation by installing a plurality of horizontal members and connecting the horizontal members with the vertical members.

  However, according to this configuration, since it is necessary to install a plurality of lateral members on the vehicle body floor, there arises a problem that the vehicle interior space is limited. Further, since the lateral member that receives the load is joined to the vehicle body floor, there is a problem that the side impact load cannot be sufficiently supported when the joint surface is peeled off.

  Therefore, the present invention reduces the height of the vehicle body floor and reduces the number of side members as much as possible while improving the side impact performance by installing the side members on the floor panel in the lower body structure of the automobile. Accordingly, an object of the present invention is to provide a lower body structure of an automobile that can widen the passenger compartment space and improve the comfort of the passenger compartment.

  The lower body structure of the automobile of the present invention includes a first floor portion located on the front side of the vehicle, an inclined portion directed upward from the rear end of the first floor portion, and a first floor portion extending rearward from the inclined portion. A floor panel having a second floor portion positioned above and a first cross that is installed on the lower surface of the inclined portion so as to extend in the vehicle width direction and forms a first closed cross section with the inclined portion A member is installed on the upper surface of the first floor portion so as to extend in the vehicle width direction, spaced apart from the inclined portion toward the vehicle front side, and a second closed cross section is formed between the member and the first floor portion. Two cross members are installed on the upper surface of the first floor portion so as to extend in the vehicle front-rear direction to form a closed cross section between the first floor portion, and the first closed cross section and the second closed cross section And a vertical member connecting the two.

According to the above configuration, the floor panel is joined to the lower surface of the inclined portion and the first cross member that forms the first closed section, and the upper surface of the first floor portion and the second cross member that forms the second closed section. The first closed member and the second closed member formed by the first cross member and the second cross member are connected by the vertical member.
For this reason, when a side collision load is received, the first closed section and the second closed section connected by the vertical members cooperate with each other above the height position of the first floor portion, and the side collision load is Can be supported. Further, the number of cross members on the floor panel can be reduced by installing the first cross member forming the first closed section on the lower surface of the inclined portion, that is, the lower surface of the floor panel. Further, since the vertical members connecting the closed cross sections are joined to the inclined portion, the first cross member does not peel from the floor panel when receiving a side collision load.

In addition, the above-mentioned floor panel includes those having a tunnel portion and those having no tunnel portion.
Further, the cross member may have any cross-sectional shape such as a cross-sectional hat shape or an L-shape as long as it forms a closed cross section extending in the vehicle width direction of the floor panel.

In one embodiment of the present invention, a body frame extending in the vehicle front-rear direction and forming a closed cross section with the first floor portion is provided on the lower surface of the first floor portion, and the body frame is attached to the vertical member. It is installed at the corresponding position, and is joined simultaneously with the vertical member via the first floor portion.
According to the above configuration, the longitudinal members can be jointed to the body frame extending in the front-rear direction at the same time, whereby the longitudinal rigidity of the vertical members can be increased, and the coupling strength between the first closed cross section and the second closed cross section is increased. Can do.
In addition, since the body frame can improve the longitudinal rigidity, the vertical member can be downsized.
Therefore, the cooperation between the first closed cross section and the second closed cross section is surely generated and the side impact load can be supported, but the protruding amount of the vertical member on the floor panel is reduced, and the passenger compartment space is reduced. Can be widened.

In one embodiment of the present invention, the first floor portion is formed with a tunnel portion that curves upward and a rear end extends to the inclined portion, and the vertical member and the body frame are connected to the side of the tunnel portion. It was installed adjacent to
According to the above configuration, by providing the vertical member and the body frame at the adjacent position on the side of the tunnel portion, the flat portion of the floor panel is not formed at the adjacent position of the tunnel portion, and a strong member is installed. Will be.
For this reason, the vertical member and the body frame can block the displacement generated by the torsion of the vehicle body of the tunnel portion constituting a part of the vehicle body skeleton together with the cross member and the frame from being directly transmitted to the floor panel.
Therefore, the floor panel vibration generated by forming the tunnel portion on the first floor portion can be suppressed using the vertical member and the body frame that are the side collision corresponding members.

In one embodiment of the present invention, a reinforcing member that reinforces from the rear end of the tunnel portion to the inclined portion is installed on the upper surface of the floor panel, and the rear end of the vertical member is joined to the reinforcing member. is there.
According to the above configuration, the rigidity of the joint portion between the tunnel portion and the inclined portion can be increased by the reinforcing member, and the joining strength between the longitudinal member and the first closed cross section can be obtained by joining the longitudinal member to the reinforcing member. Can be increased.
Therefore, the surface rigidity of the floor panel at the joint portion between the tunnel portion and the inclined portion can be increased, and the function of the vertical member when subjected to a side impact load can be further enhanced.

In one embodiment of the present invention, a front mounting bracket of a seat installed above the second floor portion is attached to the reinforcing member.
According to the above configuration, by attaching the front mounting bracket of the seat to the reinforcing member, the mounting rigidity of the seat is increased by using the reinforcing member that increases the rigidity of the joint portion between the tunnel portion and the inclined portion.
Therefore, it is possible to increase the seat mounting rigidity without separately setting a reinforcing member for mounting the seat. In particular, by attaching to the reinforcing member located at the inclined portion, the front mounting bracket can be more firmly fixed using the rigidity of the first closed cross section.

In one embodiment of the present invention, the floor panel is constituted by a front floor and a rear floor which are divided at a division position between the inclined portion and the second cross member position, and the vertical member is moved back and forth at the division position. And a superposition portion is provided at the division position of the vertical member.
According to the said structure, it becomes unnecessary to form a floor panel by one big panel body on production by comprising so that a floor panel may be divided | segmented into a front floor and a rear floor. Along with this, the vertical member is also divided into front and rear, but by providing the overlapped portion, load transmission when receiving a side collision load can be performed reliably.
Therefore, while improving the productivity of the lower vehicle body structure including the floor panel, it is possible to ensure the load transmission performance of the side member load of the vertical member with certainty and to secure the side impact performance.

In one embodiment of the present invention, a side sill provided with a slide rail of a slide door is installed outside the second cross member in the vehicle width direction.
According to the above configuration, by installing the side sill provided with the slide rail on the outer side in the vehicle width direction of the second cross member, the load from the slide door on which the side impact load acts more than a normal swing door, It can be more reliably supported by the second cross member.
For this reason, the side sill that intrudes into the inside of the vehicle body under a large side impact load can be reliably supported by the second cross member reinforced by the vertical member or the like, and the side sill enters the inside of the vehicle body Can be suppressed.
Therefore, by adopting a sliding door, a lower body structure with high side collision performance is achieved by suppressing the displacement of the side sill to the inside of the body during a side collision while adopting a highly convenient body structure. can do.

  According to this invention, when receiving a side collision load, the first closed section and the second closed section connected by the vertical members cooperate with each other on the side above the height position of the first floor portion. The impact load can be supported. Further, the number of cross members on the floor panel can be reduced by installing the first cross member forming the first closed section on the lower surface of the inclined portion, that is, the lower surface of the floor panel. Further, since the vertical members connecting the closed cross sections are joined to the inclined portion, the first cross member does not peel from the floor panel when receiving a side collision load.

  Therefore, in the lower car body structure of an automobile, while improving the side impact performance by installing a cross member etc. on the floor panel, by reducing the height of the car body floor, and further reducing the cross member as much as possible, The cabin space can be widened to improve the comfort of the cabin.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
The first embodiment will be described with reference to FIGS. 1 is a plan view of the vehicle body floor of the lower vehicle body structure of the present embodiment, FIG. 2 is a bottom view of the vehicle body floor, FIG. 3 is a side perspective view of the main part of the vehicle body floor as viewed from the outside of the vehicle, and FIG. 1 is a cross-sectional view taken along the line AA in FIG. 1, FIG. 5 is a cross-sectional view illustrating an assembly method during production of the floor panel, FIG. 6 is a cross-sectional view taken along the line BB in FIG. It is CC sectional view taken on the line.

  As shown in FIG. 1, the lower vehicle body structure of the present embodiment includes a floor panel 1 that extends horizontally from the vehicle front side to the vehicle rear side, and a side sill that extends in the vehicle front-rear direction at both ends in the vehicle width direction of the floor panel 1. 2 and 2 (the side sill outer 22 is indicated by a broken line in the drawing) and No. 2 extending in the vehicle width direction joined to the upper surface of the floor panel 1 inside the side sills 2 and 2. 2 No. 2 cross members 3 and 3 and No. 2 bonded to the upper surface of the floor panel 1 in the same manner at the rear. 3 No. 3 cross members 4 and 4 and No. 2 bonded to the lower surface of the floor panel 1 at the rear thereof. No. 4 cross member 5 (see FIG. 2) and No. 4 bonded to the lower surface of the floor panel 1 in the same manner at the rear. 5 cross member 6 (see FIG. 2), Three longitudinal members 7 and 7 extending in the vehicle front-rear direction joined to the upper surface of the floor panel 1 behind the three cross members 4 and 4; Two body frames 8 and 8 (see FIG. 2) extending in the vehicle front-rear direction joined to the lower surface of the floor panel 1 in front of the four cross member 5; Four seat slide rails 9 that extend in the vehicle front-rear direction and spaced apart in the vehicle width direction at the rear position of the four cross members 5 are provided.

First, the floor panel 1 described above has a lower floor portion 11 formed one step lower on the front side of the vehicle, A kick-up portion 12 that is an inclined portion that is inclined upward at the position of the four cross member 5 and an upper floor portion 13 that is formed one step higher on the vehicle rear side (see FIG. 4).
The lower floor portion 11 is formed with a tunnel portion 14 extending in the vehicle front-rear direction and protruding upward in the center in the vehicle width direction. Thus, the rigidity of the vehicle body is increased, and a layout space such as an exhaust pipe (not shown) extending in the vehicle front-rear direction is secured in the tunnel portion 14.
Further, the upper floor portion 13 is formed with a spare tire pan 15 that is recessed in a substantially U shape in plan view in order to accommodate a spare tire (not shown) at the center of the rear end of the vehicle.

  Further, as shown in FIG. 3, the kick-up portion 12 is inclined so as to extend upward from the upper end of the tunnel portion 14, and the rear end 14a of the tunnel portion 14 is coupled to the center in the vehicle width direction. It is formed to be. A tunnel rear end reinforcement 16 is adhered to the upper surface of the joint portion in order to increase the rigidity of the joint portion.

  As shown in FIG. 3, the tunnel rear end reinforcement 16 is formed of a substantially gusseted gusset member along the shape of the kick-up portion 12 and the tunnel portion 14, and is adhered to the upper surface of the floor panel 1. By doing so, the surface rigidity of the floor panel 1 is also increased.

  As shown in FIG. 1, the side sills 2 and 2 extend in the vehicle front-rear direction on both sides in the vehicle width direction and form a closed cross section that extends in the vehicle front-rear direction with the side sill inner 21 and the side sill outer 22. Yes. The side sills 2 and 2 are located on the inner side in the vehicle width direction below the side door (not shown).

  Further, as shown in FIG. 7, the side sill outer 22 of the side sill 2 is formed with a recess 22a that opens outward in the vehicle width direction, and a slide rail 23 of a slide door is installed in the recess 22a. Yes.

  Since the sliding door is supported by the vehicle body by the slide rail 23, the load on the side sills 2 and 2 of the vehicle adopting the sliding door as in this embodiment is larger than the load on the side sill of the vehicle adopting the normal swing door. When a side impact load is applied from the side of the vehicle, a large side impact load may be applied to the side sills 2 and 2.

  Corresponding to the installation of the sliding door, as shown in FIG. 1, the side sill inner 21 of the side sills 2 and 2 is formed with a bulging portion 21a for pulling the sliding door inward of the vehicle body when the door is closed. ing.

  The aforementioned No. The two cross members 3 and 3 are formed by member members having a substantially hat-shaped cross section, and are joined to the upper surface of the lower floor portion 11 to form a closed cross section extending in the vehicle width direction with the lower floor portion 11. This No. The two cross members 3 and 3 are installed on both the left and right sides of the tunnel portion 14, and connect the tunnel portion 14 and the side sills 2 and 2 with each other.

  The aforementioned No. Similarly, the three cross members 4 and 4 are also formed of member members having a substantially hat-shaped cross section, and are joined to the upper surface of the lower floor portion 11 so as to extend in the vehicle width direction between the lower floor portion 11 and the No. 3 cross members. Three closed sections 40 are formed (see FIG. 4). This No. The three cross members 4 and 4 are also installed on both the left and right sides with the tunnel portion 14 in between, and each connects the tunnel portion 14 and the side sills 2 and 2. In particular, this No. The outer ends of the three cross members 4 and 4 are joined to the bulging portions 21a and 21a of the side sills 2 and 2, respectively. For this reason, no. The three cross members 4 and 4 receive the largest load from the side sills 2 and 2 when receiving a side impact load.

  The aforementioned No. As shown in FIG. 2, the 4 cross member 5 is installed on the lower surface of the floor panel 1, specifically, the lower surface of the kick-up portion 12 (see FIG. 4), and the center member portion 51 having a substantially L-shaped cross section at the center. It is comprised by the side member parts 52 and 52 of the substantially hat-shaped cross section of both sides. And No. 2 extending in the vehicle width direction with the kick-up portion 12. Four closed sections 50 are formed (see FIG. 4).

  As shown in FIG. 2, the center member portion 51 is formed so that its front end portion 51 a extends to the lower surface of the lower floor portion 11 and is joined to the lower panel portion 11 in a wide range. Thereby, reinforcement of the lower part of the lower floor part 11 is also performed.

  The side member parts 52 and 52 are joined so that the outer ends thereof extend in the vertical direction with respect to the side sills 2 and 2 so as to reliably transmit the side impact load from the side sills 2 and 2 to the center member part 51. It is configured.

  In the tunnel portion 14 on the lower surface of the floor panel 1, the above-mentioned No. 2 Cross members 3, 3 and No. 2 Corresponding to the positions of the three cross members 4, 4, No. 3 having a substantially hat-shaped cross section bulging upward along the shape of the tunnel portion 14. 2 Reinforcing member 31 and No. 2 3 reinforcement members 41 are joined to each other. These reinforcing members 31 and 41 increase the rigidity of the tunnel portion 14 and 2 Cross members 3, 3 and No. 2 The rigidity of the 3 cross members 4 and 4 in the vehicle width direction is increased.

  The aforementioned No. 5 cross member 6 is installed between rear side frames 60, 60 extending to the vehicle rear side on the lower surface of floor panel 1, and is configured by a member member having a substantially hat-shaped I-shaped cross section with both ends greatly formed in a bottom view, A closed cross section extending in the vehicle width direction is formed with the upper floor portion 13.

  As shown in FIG. 3 A closed cross section 70 is formed between the cross members 4 and 4 and the kick-up portion 12 and is formed of a member member having a substantially hat-shaped cross section and extends in the vehicle front-rear direction with the lower floor portion 11 ( (See FIG. 4).

  As shown in FIG. 3, the vertical member 7 has a front flange 71 provided at the front end thereof with a No. No. 3 by joining to the rear surface or upper surface of the cross member 4 and joining the rear flange 72 provided at the rear end to the front surface of the kick-up portion 12. 3 The cross member 4 and the kick-up portion 12 are connected. That is, as shown in FIG. 3 No. 3 formed by the cross member 4 and the lower floor portion 11. 3 closed section 40, kick-up portion 12 and No. 3 No. 4 formed with 4 cross members 5 The four closed sections 50 are connected by the vertical member 7.

  Further, as shown in FIG. 3, the vertical member 7 is configured to be divided into a front and a rear by a front vertical member 7a on the front side and a rear vertical member 7b on the rear side. As will be described later, since the floor panel 1 is divided into a front floor 1F and a rear floor 1R according to production requirements, the vertical members 7 are divided corresponding to the division positions. It is. A line L extending in the vehicle width direction shown in FIG. 3 is a division position of the floor panel 1.

As shown in FIG. 2, the aforementioned body frames 8, 8 extend in the vehicle front-rear direction at adjacent positions on the side of the tunnel portion 14, are configured by member members having a substantially hat-shaped cross section, and between the lower floor portion 11. A closed cross section extending in the vehicle longitudinal direction is formed. The body frames 8, 8 are formed so that the cross-sectional area gradually decreases as the vehicle moves from the front to the rear. 4 The cross-sectional area is almost eliminated at the rear end joined to the cross member 5. The reason why the cross-sectional area is reduced in this way is to prevent stress concentration in the body frames 8 and 8 by eliminating a sudden change in the cross-sectional area.
Further, the flange portions on the inner side in the vehicle width direction of the body frames 8, 8 are formed so as to extend to the tunnel portion. Thereby, the rigidity at the boundary between the flat portion of the floor panel and the tunnel portion 14 is improved.

  As shown in FIG. 1, the seat slide rails 9 described above are seat slide rails on both ends so that a seat (not shown) installed above the upper floor portion 13 can slide back and forth over the entire area of the upper floor portion 13. 9 and 9 are extended from the front end of the upper floor portion 13 to the rear end portion of the vehicle. However, the two center seat slide rails 9 and 9 are extended to the front position of the spare tire pan 15 in consideration of taking out a spare tire (not shown).

  Among these, the front side mounting structure of the center seat slide rail 9 is performed by fastening and fixing the front side mounting bracket 91 to the tunnel rear end reinforcement 16 installed in the kick-up portion 12, as shown in FIG. ing. Specifically, as shown in FIG. 6, a fastening nut 92 is welded and fixed to the front inclined surface 16a of the tunnel rear end reinforcement 16, and the front mounting bracket 91 extending downward from the seat slide rail 9 is attached to the rear side of the tunnel. It is carried out by placing on the end reinforcement 16 and fastening and fixing with the bolt member 93.

  In the present embodiment, in order to prevent the side sills 2 and 2 from entering the vehicle interior side due to the side impact load, the above-described No. 1 is used. 2 Cross members 3, 3, No. 2 3 cross members 4, 4 and No. 3 The four cross members 5 are configured to support the side impact load from the side sills 2 and 2. In particular, no. Since the three cross members 4 and 4 receive a side impact load from the bulging portion 21a of the sliding door pull-in, a large side impact load acts.

  Therefore, in the present embodiment, as shown in FIG. 3. Connect the cross members 4 and 4 and the kick-up portion 12 to each other. The four closed cross sections 50 are also configured to distribute the side impact load. As a result, no. 3 closed section 40 and No.3. The side closed load can be supported in cooperation with the four closed sections 50, and the side collision performance can be improved.

  Here, in this embodiment, no. No. 4 forming the closed cross section 50. 4 Since the cross member 5 is joined to the lower surface of the floor panel 1 using the rise of the kick-up portion 12, the side impact performance of the vehicle is improved without increasing the cross members on the floor panel 1. Can do.

  Further, the vertical member 7 has a rear flange 72 joined to the kick-up portion 12 via a tunnel rear end reinforcement 16 (see FIG. 4). For this reason, the joining strength between the vertical member 7 and the kick-up portion 12 is increased, and even if a large side impact load is applied, there is no possibility that separation occurs between the vertical member 7 and the kick-up portion 12.

  In addition, the above-described body frame 8 is arranged below the vertical member 7 and the vertical members 7 and 7 and the body frames 8 and 8 are simultaneously joined via the lower floor portion 11 as shown in FIG. Yes. Thereby, the longitudinal direction rigidity of the vertical members 7 and 7 increases, and the load transmission performance at the time of a side collision can be improved.

  Further, as shown in FIG. 7, the vertical members 7 and 7 and the body frames 8 and 8 are installed at adjacent positions on the side of the tunnel portion 14. For this reason, a plane part is not formed in the side of this tunnel part 14, and the surface vibration of the floor panel 1 can be suppressed.

  That is, when a flat portion is formed on the side of the tunnel portion 14, a displacement caused by twisting of the vehicle body of the tunnel portion 14 constituting the vehicle body skeleton is directly transmitted to the floor panel 1, and surface vibration is applied to the floor panel 1. Will occur, causing in-vehicle noise and body vibration.

  Therefore, in this embodiment, the vertical members 7 and 7 and the body frames 8 and 8 are installed on the side of the tunnel portion 14 to block the transmission of the displacement (movement) of the tunnel portion 14, so This prevents vibrations from occurring.

  Further, as shown in FIG. 4, the vertical member 7 is provided with an overlapping portion W where the front vertical member 7a and the rear vertical member 7b overlap each other in the front-rear direction. Thereby, even if the vertical member 7 is divided into front and rear, the load transmission by the vertical member 7 when the side impact load is received is surely performed.

Next, a method for producing the floor panel 1 in this embodiment will be described.
This floor panel 1 is constituted by a front and rear division type. That is, if the floor panel 1 is formed with a single large panel body, the size of the press machine, the size of the transfer device, and the size of the panel body stacking space are increased. It is composed.

  Specifically, as shown in FIG. The floor panel 1 is divided at a position behind the installation position of the three cross members 4, and is constituted by a front floor 1F and a rear floor 1R. This figure is a sectional view showing a state in which the front floor 1F and the rear floor 1R are assembled.

  As shown in FIG. A front floor unit 100 in which front side components such as the three cross member 4 are temporarily assembled; The rear floor unit 200 in which rear components such as the four cross members 5 are temporarily assembled is configured as a temporary assembly (sub-assembly) unit, and the rear floor unit 200 is assembled from above the front floor unit 100. .

  In order to prevent the components from interfering at the time of assembly, the stepped portions of the components are configured to be shifted back and forth. Specifically, in the front floor unit 100, the rear end portion 7ae of the front vertical member 7a, the rear end portion 1Fe of the front floor 1F (the front lower floor portion 11), and the rear end portion 8e of the body frame 8 are respectively moved forward. The components on the rear floor unit 200 side are set so as not to interfere with each other.

  Here, no. The front end portion 5f of the four cross member 5 is set to extend forward from the front end portion 1Rf of the rear floor 1R (rear lower floor portion). Thus, no. No. 4 by extending the front end 5f of the cross member 5 The 4-cross member 5 can also be used as a reinforcing member for the divided portion.

  Thus, by making the floor panel 1 into a front and rear division type, in this embodiment, it is possible to avoid an increase in the size of the production equipment, and to satisfy production requirements.

  In addition, since the floor panel 1 is divided into the front and rear as described above, the surface rigidity of the floor panel 1 may be reduced and the floor panel 1 may be vibrated. 4 The front end 5f of the cross member 5 is extended forward to increase the bonding strength. 3 closed section 40 and No.3. The occurrence of vibration of the floor panel 1 is suppressed by compensating for a decrease in the surface rigidity of the floor panel 1 by connecting the four closed sections 50 to increase the bonding strength.

Next, functions and effects of this embodiment will be described.
In the lower body structure of the automobile of this embodiment, a lower floor portion 11 located on the front side of the vehicle, a kick-up portion 12 facing upward from the rear end of the lower floor portion 11, and a lower floor extending rearward from the kick-up portion 12 The floor panel 1 having the upper floor portion 13 positioned above the portion 11 and the bottom panel of the kick-up portion 12 are installed so as to extend in the vehicle width direction. No. 4 forming the closed cross section 50. No. 4 cross member 5 is installed on the upper surface of the lower floor portion 11 so as to extend in the vehicle width direction, spaced from the kick-up portion 12 to the front side of the vehicle. No. 3 forming the closed section 40. No. 3 cross members 4 and 4 are installed on the upper surface of the lower floor portion 11 so as to extend in the vehicle front-rear direction, and a closed cross section is formed between the lower floor portion 11. No. 4 closed section 50 and No. 4 Three vertical members 7, 7 connecting the three closed sections 40 are provided.

Thereby, the floor panel 1 has a lower surface of the kick-up portion 12 and a No. No. 4 forming the closed cross section 50. 4 cross member 5, the upper surface of lower floor portion 11 and No. 4 No. 3 forming the closed section 40. 3 cross members 4 and 4 are joined. 4 Cross member 5 and No. 4 No. 3 formed by the three cross members 4 and 4. No. 4 closed section 50 and No. 4 The three closed sections 40 are connected by the vertical members 7 and 7.
For this reason, when receiving a side impact load, the No. 1 connected by the vertical members 7 and 7 above the height position of the lower floor portion 11 is connected. No. 4 closed section 50 and No. 4 The three closed sections 40 can cooperate to support the side impact load. In addition, this No. No. 4 forming the closed cross section 50. Since the four cross members 5 are installed on the lower surface of the kick-up portion 12, that is, the lower surface of the floor panel 1, the number of cross members on the floor panel 1 can be reduced. Furthermore, since the vertical member 7 connecting the closed cross sections is joined to the kick-up portion 12, when receiving a side collision load, the The 4 cross member 5 does not peel from the floor panel 1.

  Therefore, in the lower body structure of an automobile, the height of the side panel 1 is reduced and the number of cross members is reduced as much as possible while improving the side impact performance by installing a cross member or the like on the floor panel 1. Thus, the cabin space can be widened to improve the comfort of the cabin.

In addition, this embodiment includes body frames 8 and 8 that extend in the vehicle front-rear direction on the lower surface of the lower floor portion 11 and form a closed cross section with the lower floor portion 11. The body frames 8 and 8 are connected to the vertical members 7 and 8. It is installed at a position corresponding to 7 and is simultaneously joined to the vertical members 7 and 7 via the lower floor portion 11.
As a result, the longitudinal rigidity of the longitudinal members 7, 7 can be increased. No. 4 closed section 50 and No. 4 The bonding strength with the three closed sections 40 can be increased.
Further, since the body frames 8 and 8 can improve the longitudinal rigidity, the vertical members 7 and 7 can be downsized.
Therefore, no. No. 4 closed section 50 and No. 4 3 While ensuring the cooperation with the closed section 40 and supporting the side impact load, the amount of protrusion of the vertical members 7 and 7 on the floor panel 1 is reduced to widen the cabin space. be able to.

Further, in this embodiment, the lower floor portion 11 is formed with a tunnel portion 14 that is curved upward and whose rear end extends to the kick-up portion 12. The vertical members 7 and 7 and the body frames 8 and 8 are connected to the tunnel portion. 14 adjacent to the sides.
Thereby, the flat part of the floor panel 1 is not formed in the adjacent position of the tunnel part 14, but a strong member is installed.
For this reason, the vertical members 7, 7 and the body frame 8, the displacement generated by the torsion of the vehicle body of the tunnel portion 14 constituting a part of the vehicle body skeleton together with the cross member and the frame are directly transmitted to the floor panel 1. 8 can prevent.
Therefore, it is possible to suppress the occurrence of vibration of the floor panel 1 caused by forming the tunnel portion 14 in the lower floor portion 11 by using the vertical members 7 and 7 and the body frames 8 and 8 that are side collision corresponding members. .

In this embodiment, a tunnel rear end reinforcement 16 is installed from the rear end of the tunnel portion 14 to the kick-up portion 12, and the rear ends of the vertical members 7 and 7 are connected to the tunnel rear end reinforcement 16. It is joined to.
Accordingly, the rigidity of the joint portion between the tunnel portion 14 and the kick-up portion 12 can be increased by the tunnel rear end reinforcement 16, and the longitudinal members 7 and 7 are joined to the tunnel rear end reinforcement 16. The vertical members 7 and 7 and No. The joint strength with the four closed sections 50 can be increased.
Therefore, the surface rigidity of the floor panel 1 at the joint portion between the tunnel portion 14 and the kick-up portion 12 can be increased, and the functions of the vertical members 7 and 7 when receiving a side collision load can be further enhanced. .

In this embodiment, a front mounting bracket 91 of a seat slide rail 9 of a seat (not shown) installed above the upper floor portion 13 is attached to the tunnel rear end reinforcement 16.
As a result, the seat mounting rigidity is increased by using the tunnel rear end reinforcement 16 that increases the rigidity of the joint portion between the tunnel portion 14 and the kick-up portion 12.
Therefore, it is possible to increase the seat mounting rigidity without separately setting a reinforcing member for mounting the seat. In particular, by attaching it to the tunnel rear end reinforcement 16 located in the kick-up portion 12, The front mounting bracket 91 can be fixed more firmly using the rigidity of the four closed cross sections 50.

In this embodiment, the floor panel 1 is composed of a front floor and a rear floor, and the vertical members 7 and 7 are divided into front and rear (front vertical member 7a and rear vertical member 7b). The overlapping portion W is provided at the dividing position.
Thus, by configuring the floor panel 1 to be divided into the front floor and the rear floor, it is not necessary to form the floor panel 1 with a single large panel body in production. Along with this, the vertical members 7, 7 are also divided into front and rear, but by providing the overlapped portion W, load transmission when receiving a side impact load can be reliably performed.
Therefore, while improving the productivity of the lower vehicle body structure including the floor panel 1, the load transmission performance of the side impact load of the vertical members 7 and 7 can be reliably ensured, and the side impact performance can be secured.

In this embodiment, no. Side sills 2 and 2 provided with slide rails 23 of sliding doors are installed outside the three cross members 4 and 4 in the vehicle width direction.
As a result, the load from the sliding door, on which the side impact load is larger than that of a normal swing door, can be more reliably determined. It can be supported by 3 cross members 4 and 4.
For this reason, the side sills 2 and 2 that enter the inner side of the vehicle body under a large side impact load are reinforced by the vertical members 7 and 7. The three cross members 4 and 4 can reliably support, and the side sills 2 and 2 can be prevented from entering the vehicle body inward.
Therefore, by adopting the sliding door, it is possible to adopt a highly convenient body structure, but also to suppress the displacement of the side sills 2 and 2 toward the inner side of the body at the time of a side collision, so that the lower body has high side collision performance. A structure can be constructed.

  In this embodiment, the lower body structure in which the tunnel portion 14 is provided in the floor panel 1 has been described. 3 cross members 4, 4 and No. 3 As long as the vertical members 7 and 7 are provided between the four cross members 5 to support the side impact load, the lower vehicle body structure may be configured by the flat floor panel 1 not provided with the tunnel portion 14. .

  Further, the cross-sectional shape of each cross member is not particularly limited as long as it forms a closed cross-section extending in the vehicle width direction with the floor panel 1.

  Further, the side sills 2 and 2 are not limited to the sliding door type side sill as in the present embodiment, but may be a general swing door type side sill.

As described above, in the correspondence between the configuration of the present invention and the above-described embodiment,
The first floor portion of the present invention corresponds to the lower floor portion 11,
Similarly,
The inclined part corresponds to the kick-up part 12,
The second floor portion corresponds to the upper floor portion 13,
The first cross member is no. 4 Corresponding to cross member 5
The second cross member is no. Corresponding to 3 cross member 4,
The first closed cross-section is No. 4 corresponds to the closed section 50,
The second closed section is No. Corresponding to 3 closed sections 40,
The reinforcing member corresponds to the reinforcement 16 at the rear end of the tunnel,
The present invention is not limited to the above-described embodiment, but includes an embodiment applied to the lower body structure of any automobile.

The top view of the vehicle body floor of the lower vehicle body structure of 1st embodiment. The bottom view of the vehicle body floor of a lower vehicle body structure. The side perspective view which looked at the principal part of the body floor from the car outside. FIG. 2 is a cross-sectional view taken along line AA in FIG. 1. Sectional drawing explaining the assembly | attachment method at the time of floor panel production. FIG. 3 is a cross-sectional view taken along line B-B in FIG. 1. The CC sectional view taken on the line of FIG.

Explanation of symbols

1 ... Floor panel 2 ... Side sill 4 ... No. 3 cross member (second cross member)
5 ... No. 4 cross members (first cross member)
7 ... Vertical member 11 ... Lower floor part (first floor part)
12 ... Kick-up part (inclined part)
13 ... Upper floor (second floor)
40 ... No. 3 closed section (second closed section)
50 ... No. 4 closed section (first closed section)

Claims (7)

A lower body structure of an automobile,
A first floor portion located on the vehicle front side, an inclined portion facing upward from the rear end of the first floor portion, and a second floor portion extending rearward from the inclined portion and positioned above the first floor portion; A floor panel having
A first cross member that is installed on the lower surface of the inclined portion so as to extend in the vehicle width direction and forms a first closed cross-section with the inclined portion;
A second cross member that is spaced apart from the inclined portion toward the front side of the vehicle and extends on the upper surface of the first floor portion so as to extend in the vehicle width direction and forms a second closed cross section with the first floor portion. When,
A vertical member that is installed on the upper surface of the first floor portion so as to extend in the vehicle longitudinal direction, forms a closed cross section with the first floor portion, and connects the first closed cross section and the second closed cross section. The lower car body structure of a car with A lower surface of the first floor portion includes a body frame that extends in the vehicle front-rear direction and forms a closed cross section with the first floor portion,
The lower body structure of an automobile according to claim 1, wherein the body frame is installed at a position corresponding to the vertical member and is simultaneously joined to the vertical member via a first floor portion. The first floor portion is curved upward and forms a tunnel portion whose rear end extends to the inclined portion,
The lower body structure of an automobile according to claim 2, wherein the vertical member and the body frame are installed adjacent to the side of the tunnel portion. A reinforcing member that reinforces from the rear end of the tunnel portion to the inclined portion is installed on the upper surface of the floor panel,
The lower body structure of an automobile according to claim 3, wherein a rear end of the vertical member is joined to the reinforcing member. The lower body structure of the automobile according to claim 4, wherein a front mounting bracket of a seat installed above the second floor portion is mounted on the reinforcing member. The floor panel is composed of a front floor and a rear floor that are divided at a dividing position between the inclined portion and the second cross member position,
The lower body structure of an automobile according to any one of claims 1 to 5, wherein the vertical member is divided back and forth at the division position, and an overlap portion is provided at the division position of the vertical member. The lower body structure of an automobile according to any one of claims 1 to 6, wherein a side sill provided with a slide rail of a slide door is installed outside the second cross member in the vehicle width direction.

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