JP2007083909A - Vehicle body lower structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To ensure the supporting rigidity of a seat even if a cross member cannot be located under a seat fixing section. <P>SOLUTION: This vehicle body lower structure is equipped with a pair of right and left body side frames 2 and 2 which extend longitudinally in the vehicle body, the cross member 4 which bridges the body side frames 2 and 2, and a floor center member 10b which extends longitudinally in the vicinity of the central section in the vehicle width direction, and is connected with the cross member 4. In the vehicle body lower structure, a rear bracket 16 which is a seat reinforcing member is attached so as to be astride the cross member 4 and the floor center member 10b. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a lower body structure of an automobile, and more particularly, to a lower body structure for increasing seat supporting rigidity.

  The seat is basically mounted on the floor panel that forms the floor of the vehicle interior. However, in order to ensure the seat support rigidity, in particular, in order to ensure the seat holding force in the event of a vehicle collision, it is often insufficient to simply mount the seat on the floor panel. Therefore, it is a common practice to firmly support the seat using the strength of the skeleton member of the vehicle body that is joined to the floor panel below.

  For example, a means is often used in which the seat mounting portion is disposed above the cross member, which is a skeleton member, and the seat mounting portion is fastened and fixed to the cross member with bolts via the floor panel. By doing so, it is possible to secure the support rigidity of the seat by utilizing the strength of the cross member.

  However, the position of the cross member in the longitudinal direction of the vehicle is determined by comprehensively considering the rigidity of the entire vehicle and the layout of parts such as a gasoline tank and a power drive system. It is not always located directly below.

  On the other hand, Japanese Patent Application Laid-Open No. 2004-168235 (Patent Document 1) discloses a structure in which a bracket is interposed between a rear seat leg that is a seat mounting portion and a cross member positioned behind the rear seat leg.

JP 2004-168235 A

  As described above, it is sufficiently conceivable to adopt a structure in which the cross member cannot be positioned directly below the seat mounting portion as the vehicle body lower structure. Therefore, further improvement of the seat support rigidity in such a structure is a request for increasing the degree of freedom of layout of the automobile.

  The invention described in the above-mentioned Patent Document 1 is a good invention in which the structure of the bracket is devised so that the strength of the cross member located behind the seat mounting portion can be used. Conversely, however, the bracket disclosed in Patent Document 1 is only for using the strength of the cross member, and does not mention that the strength of other members is further used. In this respect, it can be said that there is still room for further improving the support rigidity of the seat.

  The present invention is an improvement of the vehicle body lower structure from this viewpoint. That is, an object of the present invention is to further improve the support rigidity of the seat by more positively using the strength of the skeleton member when the cross member cannot be positioned below the seat fixing portion.

  One aspect of the present invention includes a floor panel, a skeleton member of a vehicle body joined below the floor panel, and a sheet reinforcing member interposed between the floor panel and the skeleton member to reinforce a seat attachment portion. A pair of left and right body side frames that extend in the longitudinal direction of the vehicle body, a cross member that is bridged between the pair of body side frames, and a cross member that extends in the longitudinal direction in the vicinity of the center in the vehicle width direction. And a floor center member connected to the member, wherein the sheet reinforcing member is attached across the cross member and the floor center member.

  According to this configuration, since the seat reinforcing member is mounted across the cross member and the floor center member, even if the position of the seat mounting portion and the position of the cross member do not match in the longitudinal direction of the vehicle body, It is possible to improve the support rigidity.

  According to a preferred embodiment of the present invention, the seat reinforcing member is attached to straddle the cross member and the floor center member behind the cross member, with a predetermined interval behind the cross member. It is preferable that a second cross member bridged between the pair of body side frames is further provided, and a rear end of the floor center member is joined to the second cross member.

  According to this configuration, the support rigidity of the sheet can be further increased. For example, when the vehicle has a front collision or the like, a large load is applied to the seat in the forward direction, but the rear end of the floor center member to which the seat reinforcing member is attached is the second cross member. In such a case, the sheet can be firmly supported.

  According to a preferred embodiment of the present invention, the floor center member is formed to have a concave cross-sectional shape when viewed from the front, and the reinforcing member is extended and joined to the rear end of the floor center member in the recess of the floor center member. It is preferable to have an extending part.

  According to this configuration, the support rigidity of the seat can be improved by utilizing the strength against bending obtained by forming the floor center member in a frontal sectional shape that is concave.

  According to a preferred embodiment of the present invention, the extension portion is inclined rearward and downward to extend into the recess of the floor center member, and bent portions extending rearward are provided at both ends thereof. It is preferable that the curved portion is joined to the side wall portion of the concave portion of the floor center member.

  According to this configuration, the extension portion is formed in accordance with the pulling direction at the time of the collision, and the bent portions provided at both ends thereof are joined to the side wall portions of the concave portion of the floor center member. It is possible to improve the support rigidity.

  According to a preferred embodiment of the present invention, it is preferable that the reinforcing member has a bead formed from the rear end to the inclined portion.

  According to this configuration, the bending rigidity in the vicinity of the boundary between the rear end of the reinforcing member and the extending portion can be increased.

  According to a preferred embodiment of the present invention, the cross member is formed in an inverted hat shape in a side view, and the reinforcing member is bridged to the flange portions at the front and rear ends of the cross member. It is preferable to join by a flange part.

  According to this configuration, since the reinforcing member is joined to each of the flange portions at the front and rear ends of the cross member, the rigidity of supporting the seat can be further increased by utilizing the rigidity of the cross member.

  According to the present invention, when the cross member cannot be positioned below the seat mounting portion, the strength of the skeleton member can be used more positively to further improve the seat support rigidity.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In addition, this invention is not limited to the following embodiment, It shows only the specific example advantageous for implementation of this invention. In addition, not all combinations of features described in the following embodiments are indispensable as means for solving the problems of the present invention.

  First, with reference to FIGS. 1-3, the outline of the vehicle body lower part structure in this embodiment is demonstrated. FIG. 1 is a plan view showing a vehicle body lower part structure in the present embodiment, and shows a state in which a right front seat (driver's seat) seat 50 is attached for convenience of explanation. FIG. 2 is a perspective view of the vehicle body lower part structure according to the present embodiment as viewed from the left front side, and shows a main part around the driver seat 50. FIG. 3 is a plan view similar to FIG. 1, but shows a state where the seat body of the driver's seat 50 is removed. The driver seat 50 and other seats (not shown) are basically installed on the floor panel 1 that forms the floor of the vehicle interior. However, it should be noted that in these drawings, the floor panel 1 is transmissively displayed in order to clearly show the skeleton member of the vehicle body joined below the floor panel 1. The positional relationship in the vertical direction between the floor panel 1 and other members will be clarified using a cross-sectional view.

  The vehicle body lower structure in the present embodiment includes a pair of left and right body side frames 2, 2 extending in the longitudinal direction of the vehicle body as a skeleton member, and between the pair of left and right body side frames 2, 2 in the vehicle width direction. The crossing five cross members 3, 4, 5, 6, and 7 are bridged at a predetermined interval, thereby forming a ladder type frame. These five cross members 3, 4, 5, 6, and 7 are referred to as first, second, third, fourth, and fifth cross members, respectively, in order from the vehicle body front side. The second to fifth cross members 4 to 7 are respectively terminated at the body side frames 2 and 2. On the other hand, the first cross member 3 is further connected to the side sills 8 and 8.

  As can be seen from FIG. 2, each of the first, second, and third cross members 3, 4, and 5 protrudes upward at a substantially central position in the vehicle width direction. A floor tunnel 9 extending in the longitudinal direction of the vehicle body is formed. A drive shaft (not shown) is disposed below the floor tunnel 9.

  On both sides of the floor tunnel 9, a pair of left and right first floor center members 10a, 10a extending from the first cross member 3 to the front of the vehicle body along the floor tunnel 9 are provided. As shown in FIG. 1, the front end portions of the first floor center members 10a and 10a are bent outwardly of the vehicle body and joined to the body side frames 2 and 2, respectively. Further, on both sides of the floor tunnel 9, a pair of left and right second floor center members 10 b and 10 b are provided in which one end is joined to the second cross member 4 and the other end is joined to the third cross member 5. Further, on both sides of the floor tunnel 9, a pair of left and right third floor center members 10 c and 10 c are also provided in which one end is joined to the fourth cross member 6 and the other end is joined to the fifth cross member 7. As described above, the vehicle body lower structure in the present embodiment includes the three types of floor center members extending in the front-rear direction near both sides of the floor tunnel 9, that is, near the center in the vehicle width direction.

  These floor center members are provided along both side portions of the floor tunnel 9 and have a function of reinforcing the floor tunnel 9, and are also called tunnel side members. However, in the present specification, the body side frame is provided on the end portion side in the vehicle width direction, whereas it is referred to as a floor center member by paying attention to the fact that it is provided near the center portion.

  The skeleton structure forming the lower part of the vehicle body of the present embodiment is generally as described above. In the present embodiment, the body side frame 2, the first to fifth cross members 3 to 7, and the first to third floor center members 10a to 10c described above are substantially rectangular plate-like members, respectively. It is assumed that the member is a member bent so that the cross section in the hand direction has an inverted hat shape. Therefore, each of the first to fifth cross members 3 to 7 is formed in a reverse hat shape in cross-sectional view in side view, and the flange portions formed at the front end and the rear end of the hat are used for connecting each part. . On the other hand, each of the body side frame 2 and the first to third floor center members 10a to 10c only needs to be formed to have at least a concave cross-sectional shape when viewed from the front. It is formed in a reverse hat shape so as to be provided. In this case, the flange portion is formed at the left end and the right end of the hat. Such a cross-sectional shape will be clarified later using a cross-sectional view.

  As shown in FIGS. 1 and 2, for example, a driver's seat (hereinafter simply referred to as “seat”) 50 is located above the right body side frame 2 and the first cross member 3 and the second cross. It is arranged at a position between the members 4. Hereinafter, a specific mounting structure of the seat 50 will be described in addition to the exploded perspective view of FIG. It should be noted that the floor panel 1 is also omitted in FIG.

  3 and 4, reference numeral 11 denotes a base portion on which the seat main body is placed. Known seat rails 12 and 12 are provided at the left and right ends, and seat legs 13a as seat attachment portions are provided at the four corners, respectively. , 13b, 13c, 13d are formed.

  The flange portions at the front and rear ends of the first cross member 3 are respectively located at a position between the right body side frame 2 and the right side sill 8 and a position at which the first floor center member 10a is joined. Front brackets 15a and 15b that are bridged to each other are attached by spot welding, for example. Then, the right front seat leg 13a and the left front seat leg 13b are fastened and fixed thereto by bolts 14 and 14 through the floor panel 1, respectively. Thus, since the front seat legs 13a and 13b are directly fastened and fixed to the floor panel 1 and the first cross member 3, sufficiently high support rigidity is obtained for this portion.

  Similarly, if the rear seat legs 13c and 13d can also be fastened and fixed directly to the floor panel 1 and the second cross member 4, a sufficiently high support rigidity can be obtained also for this portion. However, in the present embodiment, the distance between the first cross member 3 and the second cross member 4 is set to be shorter than the length of the seat rail 12 in the longitudinal direction of the vehicle body. For this reason, the rear seat legs 13c and 13d are located behind the second cross member 4 and cannot be directly fastened and fixed to the second cross member 4.

  Therefore, in the present embodiment, the right rear seat leg 13c is fastened and fixed with bolts 14 to the upper surface of the bulging portion 8a of the right side sill 8 that bulges toward the vehicle interior side in order to erect the center pillar. On the other hand, the left rear seat leg 13d is fastened and fixed to the rear bracket 16 having a different function from the front brackets 15a and 15b. The rear bracket 16 is interposed between the floor panel 1 and the skeleton member, and serves as a seat reinforcing member that reinforces the support of the left rear seat leg 13d. (In the present embodiment, the second cross member 4) and the floor center member (in the present embodiment, the second floor center member 10b) are attached to straddle. By interposing such a rear bracket 16, not only the second cross member 4 but also the strength of the second floor center member 10b can be used, and the seat legs 13c and 13d and the second cross as in the present embodiment. Even if the member 4 does not match the longitudinal direction of the vehicle body, it is possible to improve the support rigidity of the seat.

  Moreover, in the present embodiment, the rear end of the second floor center member 10b is joined to the third cross member 5, which also contributes to increasing the seat support rigidity. For example, when the vehicle collides forward, a large load acts on the seat in the forward direction. On the other hand, since the rear end of the second floor center member 10b to which the rear bracket 16 is attached is joined to the third cross member 5, the sheet can be firmly supported even in such a case.

  With reference to FIGS. 5-7, the specific structure of the back bracket 16 and its attachment aspect are demonstrated. 5 is a perspective view of the rear bracket 16, FIG. 6 is a side view of the rear bracket, and FIG. 7 is a perspective view showing how the rear bracket 16 is attached to the second cross member 4 and the second floor center member 10b.

  In these drawings, the front end 17 of the rear bracket 16 is joined to the flange 4 a formed at the front end of the second cross member 4, and the region 18 at the rear end of the rear bracket 16 is the second cross member 4. It becomes a joint part with the flange 4b formed in the rear end. Accordingly, the intermediate region 23 between the front end side joint portion 17 and the rear end side joint portion 18 of the rear bracket 16 is bridged between the front and rear end flanges 4 a-4 b of the second cross member 4. This is the area. For the top plate region 23, it is preferable to form a bead 24 as shown in the figure in order to increase the bending rigidity. In addition, the joint part 17 on the front end side and the joint part 18 on the rear end side of the rear bracket 16 are joined to the flanges 4a and 4b together with the floor panel 1 by spot welding, for example. In this embodiment, the rear bracket 16 is joined to the flanges 4a and 4b at the front and rear ends of the second cross member 4 as described above. Therefore, the stiffness of the second cross member 4 is used to support the seat. Has succeeded in enhancing.

  A bolt hole 19 through which the bolt 14 shown in FIG. 4 is inserted is formed behind the joint 18 on the rear end side of the rear bracket 16. A welt nut 19a is provided on the back side of the bolt hole 19 as shown in FIG. Then, the left rear seat leg 13d is fastened and fixed to the bolt hole 19 by the bolt 14 via the floor panel 1 (see FIGS. 9 and 10 described later). The left and right ends of the bolt hole 19 are joined together with the floor panel 1 to the left and right flanges formed in the second floor center member 10b.

  An extension 20 is formed at the rear end of the rear bracket 16 so as to extend into the recess of the second floor center member 10b. The extension part 20 in this embodiment is extended in the recessed part of the 2nd floor center member 10b by inclining back and downward like illustration. Further, bent portions 21 and 21 extending rearward are provided at both ends of the extension portion 20. The bent portions 21 and 21 are joined to the side wall portions 25 and 26 of the recesses of the second floor center member 10b, for example, by spot welding. The bent portions 21 and 21 are formed in accordance with the pulling direction at the time of a frontal collision, and these portions are joined to the side wall portions 25 and 26 of the concave portion of the second floor center member 10b. Therefore, it is possible to secure a high sheet supporting rigidity that can be countered.

  Further, a bead 22 is formed on the rear bracket 16 from the rear end thereof to the inclined portion of the extending portion 20. The bead 22 can increase the bending rigidity in the vicinity of the boundary between the rear end of the rear bracket 16 and the extending portion 20.

  Next, the vehicle body lower part structure in the present embodiment will be described including the positional relationship of the floor panel 1 with reference to the cross-sectional views of FIGS.

  FIG. 8 is a cross-sectional view taken along the line AA in FIG. 3 and shows a cross-sectional structure along a line connecting the right front seat leg 13a and the right rear seat leg 13c. According to FIG. 8, the cross-sectional shape of the first cross member 3 located below the right front seat leg 13a in a side view is formed in an inverted hat shape, and the front bracket 15a forms a closed cross section. It can be clearly understood that the first cross member 3 is bridged by the flanges at the front and rear ends. The floor panel 1 is laid on the upper surface of the front bracket 15a, and the right front seat leg 13a is fastened and fixed together with the front bracket 15a and the floor panel 1 by bolts 14. On the other hand, the right rear seat leg 13 c is fastened and fixed by the bolt 14 together with the structural members of the floor panel 1 and the bulging portion 8 a of the side sill 8.

  FIG. 9 is a cross-sectional view taken along the line BB of FIG. 3 and shows a cross-sectional structure along a line connecting the left front seat leg 13b and the left rear seat leg 13d. In FIG. 9, the cross-sectional shape of the second cross member 4 that is positioned forward and lower than the left rear seat leg 13d is formed in a reverse hat shape, and the rear bracket 16 is closed. The point which is bridged by the flanges 4a and 4b of the front-back end of the 2nd cross member 4 so that a cross section may be formed appears clearly.

  FIG. 10 is a cross-sectional view taken along the line CC of FIG. 3 and shows a cross-sectional structure along a line connecting the left rear seat leg 13d and the right rear seat leg 13c immediately after the second cross member 4. According to FIG. 10, the cross-sectional shape of the second floor center member 10b to which the rear bracket 16 is attached is formed in a concave shape (in the illustrated example, a reverse hat shape), and the rear bracket 16 forms a closed cross section. It will be understood that a bridge is provided between the flanges at both ends of the second floor center member 10b.

  In the above embodiment, the structure related to the driver's seat has been described as a representative, but it goes without saying that the same configuration can be applied to other seats such as the left front seat (passenger seat). In this regard, for example, in FIGS. 1 to 3, the rear bracket 16 for the passenger seat is shown, and the configuration is the same as that on the driver seat 50 side, and therefore the description is merely omitted.

It is a top view which shows the vehicle body lower part structure in embodiment of this invention. It is the perspective view which looked at the vehicle body lower part structure in embodiment of this invention from the left front. It is a top view which shows the vehicle body lower part structure in embodiment of this invention, Comprising: It is a figure which shows the state which removed the seat main body of the driver's seat. It is a disassembled perspective view of the principal part of the vehicle body lower part structure in embodiment of this invention. It is a perspective view of the back bracket in the embodiment of the present invention. It is a side view of the back bracket in the embodiment of the present invention. It is a perspective view which shows the attachment aspect of the back bracket in embodiment of this invention. It is AA sectional drawing of FIG. It is BB sectional drawing of FIG. It is CC sectional drawing of FIG.

Explanation of symbols

1: Floor panel 2: Body side frames 3-7: First to fifth cross members 8: Side sill 9: Floor tunnel 10a: First floor center member 10b: Second floor center member 10c: Third floor center member 11: Seat base 12: Seat rails 13a to 13d: Seat legs 15a, 15b: Front bracket 16: Rear bracket

Claims (6)

A vehicle body lower structure comprising a floor panel, a skeleton member of a vehicle body joined below the floor panel, and a seat reinforcement member interposed between the floor panel and the skeleton member to reinforce a seat attachment portion. And
A pair of left and right body side frames extending in the longitudinal direction of the vehicle body;
A cross member bridged between the pair of body side frames;
A floor center member extending in the longitudinal direction of the vehicle body near the center in the vehicle width direction and connected to the cross member;
With
The vehicle body lower structure, wherein the seat reinforcing member is attached across the cross member and the floor center member. The seat reinforcing member is attached to straddle the cross member and the floor center member behind the cross member,
A second cross member bridged between the pair of body side frames at a predetermined interval behind the cross member;
The vehicle body lower part structure according to claim 1, wherein a rear end of the floor center member is joined to the second cross member. The floor center member has a concave cross-sectional shape when viewed from the front,
The vehicle body lower part structure according to claim 2, wherein the reinforcing member has an extended portion at a rear end thereof that extends and is joined into a recessed portion of the floor center member.   The extending portion is inclined rearward and downward to extend into a recess of the floor center member, and bent portions extending rearward are provided at both ends thereof, and the bent portions are sidewalls of the recess of the floor center member. The vehicle body lower part structure according to claim 3, wherein the lower part structure is joined to a part.   The vehicle body lower part structure according to claim 4, wherein the reinforcing member has a bead formed from the rear end to the inclined portion. The cross member is formed in a reverse hat shape in cross-sectional view in side view,
The vehicle body lower structure according to any one of claims 1 to 5, wherein the reinforcing member is bridged to and joined to flange portions at front and rear ends of the cross member.

Images