JP6161038B2 - Auto body structure - Google Patents

Description

  In the present invention, a cross member having a closed cross section having an upper wall and a lower wall and arranged in the vehicle width direction is formed by bending a single rectangular metal plate by roll forming and welding both ends. Further, the present invention relates to a vehicle body structure in which a nut for fastening a seat or a seat belt anchor is fixed to the lower surface of the upper wall.

  Patent Document 1 below discloses a cross member having a closed cross-section by fixing a pair of front and rear flange portions of a hat-shaped cross-section member to the upper surface of a floor panel and fixing a leg portion of a seat to the cross member. It is.

  Further, it is known from Patent Document 2 below that a bumper beam of an automobile is formed by bending a single metal plate into an 8-shaped cross section and welding both ends.

JP 2010-36812 A Japanese Patent No. 3204635

  By the way, what was described in the above-mentioned patent document 1 is that the member constituting the upper part of the cross member has a hat-like cross section and is joined to the upper surface of the floor panel to form a closed cross section. When the seat belt anchor is fixed, if a load is input from the seat leg or the seat belt anchor at the time of a frontal collision of the vehicle, the joint of the cross member may be deformed by opening without being able to withstand the load. .

  Moreover, although the bumper beam described in the said patent document 2 can obtain high intensity | strength although it is lightweight with an 8-shaped cross section, applying this cross-sectional shape to a cross member is not disclosed.

  The present invention has been made in view of the above circumstances, and an object thereof is to firmly fix a seat or a seat belt anchor to a cross member while minimizing an increase in weight.

In order to achieve the above object, according to the first aspect of the present invention, a cross member having a closed cross section having an upper wall and a lower wall and arranged in the vehicle width direction is provided as one rectangular metal. It is a vehicle body structure of an automobile in which a plate is bent by roll forming and welded at both ends, and a nut for fastening a seat or a seat belt anchor is fixed to the lower surface of the upper wall. A partition that connects the upper wall and the lower wall is provided, and is configured in a laterally 8-shaped cross section. The metal plate is bent to the front side or the rear side above the partition wall, and the upper wall is overlapped by two sheets. part the nut on the lower surface is fixed, and the metal plate is the lower wall bent front below said partition wall have a portion of a two-ply, in the vehicle width direction both end portions of the cross member Top surface and closed section Laser welding of the upper surface and the inner surface in the vehicle width direction of the yaside frame, and the upper surface and the front surface of both ends in the vehicle width direction of the cross member having another closed cross section disposed in front of the cross member via a pair of left and right gussets A vehicle body structure characterized by joining by the above is proposed.

  According to the invention described in claim 2, in addition to the structure of claim 1, there is proposed a vehicle body structure for an automobile characterized in that a work hole for fixing the nut is formed in the lower wall. The

According to the invention described in claim 3, in addition to the configuration of claim 1 or claim 2, the front and bottom surfaces of both ends of the cross member in the vehicle width direction and the vehicle width direction of the rear side frame of the closed cross section. A vehicle body structure is proposed in which the inner surface and the lower surface are joined by laser welding through a pair of left and right gussets .

Incidentally, Embodiment middle cross member 13 corresponds to the other cross member of the present invention, correspond to the cross member of the rear cross member 14 is the invention of the embodiment, the rear seat 19 of the embodiment of the present invention Corresponding to the sheet, the weld nut 22 of the embodiment corresponds to the nut of the present invention.

  According to the configuration of claim 1, a cross member having a closed cross section having an upper wall and a lower wall and disposed in the vehicle width direction is bent by rolling a single rectangular metal plate. Since it is constructed by welding, a cross member having a closed cross section can be manufactured at low cost. In addition, the cross member is provided with a partition wall connecting the upper wall and the lower wall, and is configured in a transverse 8-shaped cross section, and the metal plate is folded forward or rearward above the partition wall so that two upper walls overlap. Since the nut is fixed to the lower surface of the part, and the metal plate is bent to the front side below the partition wall and the lower wall has a two-layered part, it is a cross member with a lightweight structure that does not require a special reinforcing member The upper wall and the lower wall of the seat can be reinforced to increase the fastening portion strength of the seat or the seat belt anchor.

Further, the upper surface of both ends in the vehicle width direction of the cross member, the upper surface of the rear side frame of the closed cross section and the inner surface in the vehicle width direction, and both ends of the cross member in the vehicle width direction of the other closed cross section disposed in front of the cross member. Since the upper surface and the front surface are joined by laser welding through a pair of left and right gussets, high joining strength can be obtained while rationalizing the joining of the two front and rear cross members to the rear side frame having a closed cross section.

  According to the second aspect of the present invention, since the work hole for fixing the nut is formed in the lower wall, the nut can be easily fixed inside the cross member having the closed cross section.

According to the configuration of claim 3, the front surface and the lower surface of both ends of the cross member in the vehicle width direction and the inner surface and the lower surface of the closed side rear side frame in the vehicle width direction are joined by laser welding via a pair of left and right gussets. Therefore, the cross member having the closed cross section and the rear side frame having the closed cross section can be firmly joined with high workability .

The perspective view of the fixing | fixed part vicinity of the rear seat of a motor vehicle. (First embodiment) FIG. 2 is a two-way arrow view with the rear seat removed from FIG. 1. (First embodiment) FIG. 3 is an enlarged view of part 3 of FIG. 2. (First embodiment) FIG. 4 is an enlarged sectional view taken along line 4-4 of FIG. (First embodiment) FIG. 5 is an enlarged sectional view taken along line 5-5 in FIG. (First embodiment) The figure corresponding to FIG. (Second and third embodiments)

  Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. In the present specification, the front-rear direction, the left-right direction (vehicle width direction), and the up-down direction are defined with reference to an occupant seated in the driver's seat.

  As shown in FIG. 1 and FIG. 2, a pair of left and right rear side frames 12, 12 extend rearward from the rear ends of a pair of left and right side sills 11, 11 of the automobile, and the rear ends of the left and right side sills 11, 11. The middle cross member 13 with a closed cross section extending in the vehicle width direction is connected, and the front ends of the left and right rear side frames 12 and 12 are connected with a rear cross member 14 with a closed cross section extending in the vehicle width direction. The rear end of the floor panel 15 connecting the left and right side sills 11 and 11 and the lower end of the middle cross member 13 are connected by a front panel 16 extending in the vertical direction, and the rear end of the middle cross member 13 and the rear cross member 14 are connected. The front end is connected by a rear panel 17 extending in the horizontal direction, and the left and right rear side frames 12 and 12 are connected by a rear floor panel 18. A rear seat 19 is disposed above the middle cross member 13, and six mounting brackets 20 provided on the lower surface of the rear portion of the rear seat 19 are fastened to the upper surface of the rear cross member 14 with bolts 21.

  As shown in FIGS. 3 to 5, the rear cross member 14 having an eight-shaped (or day-shaped) closed cross section in the longitudinal direction is formed by bending a single rectangular steel sheet by roll forming, and both ends. Are welded W1 and W2, and include an upper wall 14a and a lower wall 14b that face each other, a front wall 14c and a rear wall 14d that face each other, and a partition wall 14e that connects the upper wall 14a and the lower wall 14b. A portion where the upper wall 14a is welded W1 is overlapped on the rear side of the partition wall 14e, and a portion where the lower wall 14c is welded W2 is overlapped on the front side of the partition wall 14e. The partition wall 14e is located forward of the intermediate position between the front wall 14c and the rear wall 14d, and a total of seven weld nuts 22 are provided on the lower surface of the portion where the two upper walls 14a are stacked on the rear side of the partition wall 14e. ... is fixed. The lower wall 14b facing the lower side of the weld nuts 22 is provided with working holes 14f having a diameter larger than that of the weld nuts 22 ..., and the weld nuts 22 are formed on the lower surface of the upper wall 14a through the work holes 14f. ... can be easily welded.

  A pair of left and right gussets 23 are connected to the upper surfaces of both ends in the vehicle width direction of the rear cross member 14, the upper surfaces and inner surfaces in the vehicle width direction of the rear side frames 12 and 12, and the upper surfaces and front surfaces of both ends in the vehicle width direction of the middle cross member 13. , 23, and the front and lower surfaces of the rear cross member 14 at both ends in the vehicle width direction and the inner and lower surfaces of the rear side frames 12 and 12 in the vehicle width direction are connected to a pair of left and right. By connecting by welding W4 (laser welding) through the gussets 24, 24, both ends in the vehicle width direction of the rear cross member 14 are firmly fixed to the left and right rear side frames 12, 12.

  Next, the operation of the first embodiment of the present invention having the above configuration will be described.

  In order to fix the mounting brackets 20 provided on the rear lower surface of the rear seat 19 to the rear cross member 14, bolts 21 penetrating the mounting brackets 20 from the top to the bottom are fixed to the lower surface of the upper wall 14 of the rear cross member 14. The weld nuts 22 may be fastened.

  If a forward inertial force is applied to the rear seat 19 and the passenger seated in the vehicle due to a frontal collision, an upward load is applied to the mounting brackets 20 of the rear seat 19, so that the intermediate portion in the vehicle width direction of the rear cross member 14 is By pulling upward and bending, a tensile load acts on the upper wall 14a and a compressive load acts on the lower wall 14b. The lower wall 14b of the rear cross member 14 is formed with a plurality of work holes 14f for attaching the weld nuts 22 ..., and in order to prevent the strength of the rear cross member 14 from being reduced by these work holes 14f ... Increasing the thickness of the steel plate that is the material of the rear cross member 14 causes a problem that causes an increase in weight.

  However, according to the present embodiment, the rear cross member 14 includes the partition wall 14e that connects the upper wall 14a and the lower wall 14b and is configured in an eight-shaped cross section, and the weld nuts 22. Since the upper wall 14a and the lower wall 14a are connected not only by the front wall 14c and the rear wall 14d but also by the partition wall 14e and the strength is increased, the thickness of the steel plate of the rear cross member 14 is increased. Without increasing, it is possible to reinforce the rear cross member 14 with a lightweight structure and increase the fastening portion strength of the rear seat 19.

  In addition, since the weld nuts 22 are fixed to the portion where the two steel plates are overlapped, the fixing portion of the weld nuts 22 is reinforced without the need for a special reinforcing member, thereby further increasing the strength of the fastening portion of the rear seat 19. Can do. Moreover, since the rear cross member 14 is formed by bending one steel plate by roll forming, the rear cross member 14 having an 8-shaped cross section can be manufactured at low cost.

  Further, the upper surface of both ends in the vehicle width direction of the rear cross member 14, the upper surface and inner surface in the vehicle width direction of the rear side frame 12, and the upper surface and front surface of both ends in the vehicle width direction of the middle cross member 13 are laser welded via gussets 23. Since the front and lower surfaces of both ends in the vehicle width direction of the rear cross member 14 and the inner and lower surfaces in the vehicle width direction of the rear side frame 12 are bonded by the laser welding W4 via the gusset 24, the closed cross section is formed. A high joining strength can be obtained while rationalizing the joining of the rear cross member 14 having the closed cross section and the middle cross member 13 having the closed cross section to the rear side frame 12.

Second and third embodiments

  Next, second and third embodiments of the present invention will be described with reference to FIG.

  The rear cross member 14 of the second embodiment shown in FIG. 6 (A) differs from the first embodiment in the way of bending the steel sheet by roll forming, and is a steel sheet welded to the lower surface of the upper wall 14a. Is welded W1 to the lower surface of the upper wall 14a on the front side of the partition wall 14e. In the present embodiment, since the upper wall 14a to which the weld nut 22 is fixed does not overlap, the support strength of the weld nut 22 is superior to that of the first embodiment.

  The rear cross member 14 of the third embodiment shown in FIG. 6B is made of an extruded aluminum material instead of bending a steel plate and welding W1 and W2. According to the present embodiment, the manufacturing process is easy because the welding process of the steel sheet is not necessary.

  The embodiments of the present invention have been described above, but various design changes can be made without departing from the scope of the present invention.

  For example, the cross member of the present invention is not limited to the rear cross member 14 of the embodiment, and may be any cross member.

  Further, instead of the rear seat 11, a front seat or middle seat mounting bracket or a seat belt anchor may be fixed to the cross member.

  In the embodiment, the weld nuts 22 are disposed on the rear side of the partition wall 14e, but may be disposed on the front side of the partition wall 14e.

  In the embodiment, the mounting bracket 20 of the rear seat 19 is fastened to the weld nuts 22. However, the seat belt anchor of the rear seat 19 may be fastened.

  Further, instead of the weld nuts 22 in the embodiment, nuts fixed by caulking may be used.

12 Rear side frame 13 Middle cross member (other cross members)
14 Rear cross member (cross member)
14a Upper wall 14b Lower wall 14e Partition wall 14f Working hole 19 Rear seat
22 Weld nut (nut)
23 Gusset 24 Gusset W3 Laser welding W4 Laser welding

Claims (3)

A cross member (14) having a closed cross section having an upper wall (14a) and a lower wall (14b) and arranged in the vehicle width direction is bent at one end by roll forming a single rectangular metal plate. It is constructed by welding (W1, W2), and is a vehicle body structure of an automobile in which a nut (22) for fastening a seat (19) or a seat belt anchor is fixed to the lower surface of the upper wall (14a),
The cross member (14) includes a partition wall (14e) connecting the upper wall (14a) and the lower wall (14b), and is configured in a laterally eight-shaped cross section, and the metal plate is formed of the partition wall (14e). The nut (22) is fixed to the lower surface of a portion where the upper wall (14a) is overlapped by being folded forward or rearward at the upper side, and the metal plate is located on the front side below the partition wall (14e). bent by said lower wall (14c) is have a portion of a two-ply,
The upper surface of both ends in the vehicle width direction of the cross member (14), the upper surface and inner surface in the vehicle width direction of the rear side frame (12) having a closed cross section, and other closed cross sections disposed in front of the cross member (14). A vehicle body structure for an automobile, wherein the upper surface and the front surface of both ends in the vehicle width direction of the cross member (13) are joined by laser welding (W3) through a pair of left and right gussets (23) .   The vehicle body structure according to claim 1, wherein a work hole (14f) for fixing the nut (22) is formed in the lower wall (14b).   Laser welding (W4) through a pair of left and right gussets (24) is performed on the front and lower surfaces of both ends in the vehicle width direction of the cross member (14) and the inner and lower surfaces in the vehicle width direction of the rear side frame (12) having a closed cross section. The vehicle body structure of an automobile according to claim 1 or 2, wherein

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