Understructure of vehicle

Abstract

To materialize an understructure of a vehicle that prevents rupture of an impact point by dispersing a load imposed on the impact point near a seatbelt anchor attachment part of a floor panel at the time of vehicle collision.SOLUTION: An understructure of a vehicle includes a seatbelt anchor attachment part 18 formed on a floor panel 10 of the vehicle, and a plurality of beads 22 that are formed on the floor panel 10 and located outside, in a vehicle width direction, of the seatbelt anchor attachment part 18. The plurality of beads 22 extend in a vehicle front-rear direction and are arranged in the vehicle width direction. As for the lengths of the respective beads 22, the more outward a bead is located in the vehicle width direction, the longer the bead is.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a lower structure of a vehicle, and more particularly to a structure in the vicinity of a seat belt anchor attachment portion.

Background Art

[0002] Conventionally, a lower structure of a vehicle in which a seat belt anchor of a seat belt device is attached to a floor panel has been known. In such a structure, at the time of a vehicle collision, a load is input from a seat belt device that restrains an occupant to a floor panel (specifically, an inclined surface portion of the floor panel, etc.) to which the seat belt anchor is attached. The load received by this inclined surface portion is a tensile load toward the front side in the vehicle longitudinal direction, and due to the action of this tensile load, stress concentrates on a specific welded portion near the seat belt anchor, and a part of the floor panel may break or deform, or the floor panel may peel off from the side frame joined to the floor panel. Therefore, various techniques related to the lower structure of a vehicle have been proposed, such as a technique for increasing the rigidity of the floor panel itself and a technique for dispersing the above-mentioned tensile load.

[0003] For example, Patent Document 1 discloses a lower structure of an automobile in which a seat belt anchor is attached to an inclined surface portion of a floor panel. In this lower structure of the automobile, a raised step portion is formed at a portion where the side frame of the floor panel is joined, and a bulging portion that bulges inward in the vehicle width direction is formed on this raised step portion. With such a configuration, a load acting in the vehicle width direction at the time of a vehicle collision is dispersed in the vehicle longitudinal direction by the bulging portion, and stress concentration at the joint portion between the floor panel and the side frame is alleviated. As a result, it is said that peeling between the floor panel and the side frame can be suppressed.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Incidentally, in the vehicle body, spot welding may be used for joining members, and there may be a large number of dots, which are the welded parts by spot welding, on the floor panel. Here, at the time of a vehicle collision, stress may concentrate on a specific location of the floor panel, causing a load to be applied to the dots in the vicinity, and the dots may break. For example, at the time of a vehicle collision, the seat belt anchor mounting portion may be pulled forward and obliquely upward of the vehicle (i.e., in a direction in which the floor panel is lifted). At this time, a load is applied to the dots in the vicinity of the seat belt anchor mounting portion, and the dots may break.

[0006] In order to prevent the breakage of the dots as described above, it is effective to prevent the load applied to the dots from concentrating, that is, to disperse the load in order to suppress the load. However, there is room for improvement in the method of dispersing the load.

[0007] Therefore, in this specification, a vehicle lower structure is realized that prevents breakage of the dots by dispersing the load applied to the dots in the vicinity of the seat belt anchor mounting portion of the floor panel at the time of a vehicle collision.

Means for Solving the Problems

[0008] The vehicle lower structure disclosed in this specification includes a seat belt anchor mounting portion provided on a floor panel of the vehicle, and a plurality of beads provided on the floor panel, the plurality of beads being provided outside the seat belt anchor mounting portion in the vehicle width direction. The plurality of beads extend along the vehicle front-rear direction and are arranged in the vehicle width direction, and the length of each of the plurality of beads is longer for the beads located outside in the vehicle width direction.

Effects of the Invention

[0009] According to the vehicle's underbody structure disclosed in this specification, since a plurality of beads that are longer the farther they are located outward are provided on the outside in the vehicle width direction of the seat belt anchor mounting portion, when the vehicle collides, the load applied to the vicinity of the seat belt anchor mounting portion can be made to flow outward along the plurality of beads. That is, the load applied to the vicinity of the seat belt anchor mounting portion can be dispersed.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Embodiments for Carrying Out the Invention

[0011] Hereinafter, the vehicle's underbody structure will be described with reference to the drawings. In each figure, "Fr", "Up", and "Rh" indicate the front, upper, and right sides of the vehicle, respectively.

[0012] FIG. 1 is a schematic plan view of the floor panel. The vehicle's underbody structure includes a floor panel 10, which is a member that forms the lower floor of the vehicle in the vehicle's vertical direction. The floor panel 10 has, in the vehicle's front-rear direction, in order from the front side, a horizontal surface portion 12 that constitutes the floor surface in the vehicle interior, an inclined surface portion 14 that extends upward and obliquely from the rear end of the horizontal surface portion 12, and a rear horizontal surface portion 16 that extends further rearward from the rear end of the inclined surface portion 14. Also, as shown in FIG. 1, there are a large number of portions called "dots" welded by spot welding on the floor panel 10 for connecting the divided panels to each other or connecting the panel to other members.

[0013] On the inclined surface portion 14, a seat belt anchor mounting portion 18 is provided. The seat belt anchor mounting portion 18 is a member to which a seat belt anchor (not shown) that is a part of the seat belt device and supports the lower end portion of the seat belt is attached. In FIG. 1, the left seat belt anchor mounting portion 18 in the vehicle traveling direction among the seat belt anchor mounting portions 18 on the left and right and its peripheral portion are surrounded by a two-dot chain line, and an enlarged view A thereof is shown.

[0014] As shown in the enlarged view A of FIG. 1, in the floor panel 10, the above-described dots are also provided in the vicinity of the seat belt anchor mounting portion 18. Hereinafter, the dots in the vicinity of the seat belt anchor mounting portion 18 are referred to as "dots 20". The dots 20 are, for example, spot welds with a structural member located below the floor panel 10. In this example, two dots 20a and 20b are shown, and the dot on the bead side described later is defined as the dot 20b. Hereinafter, when the two dots are not particularly distinguished, they are collectively simply referred to as dots 20.

[0015] Further, a plurality of longitudinally long beads 22 extending along the vehicle longitudinal direction are provided on the inclined surface portion 14 of the floor panel 10. The plurality of beads 22 are provided outside the seat belt anchor mounting portion 18 in the vehicle width direction. In this example, three beads 22a, 22b, and 22c are provided in order from the vehicle inner side to the outer side. Hereinafter, when the three beads are not particularly distinguished, they are collectively referred to simply as bead 22. The length of each of the three beads 22 is longer for the bead located on the outer side in the vehicle width direction. That is, bead 22a is the shortest, bead 22b has an intermediate length, and bead 22c is set to be the longest. More specifically, the lengths of the lower ends of the three beads 22a, 22b, and 22c are set to be gradually longer for the beads toward the outside. For example, as shown by the dashed line in FIG. 1, it is set such that a straight line can be drawn by connecting the lower ends of the three beads 22a, 22b, and 22c. In this example, the number of the plurality of beads 22 is three, but the number is not particularly limited. Further, the floor panel 10 is usually composed of a metal plate such as a steel plate, and the bead 22 can be formed by press molding, but is not limited thereto.

[0016] Next, with reference to FIG. 2, the load applied to the vicinity of the seat belt anchor mounting portion 18 will be described. FIG. 2 is a diagram for explaining the load in the vicinity of the seat belt anchor mounting portion during a vehicle collision. More specifically, FIG. 2 is a diagram showing a portion of the enlarged view A in FIG. 1, and a cross-sectional view taken along line B-B is further shown below the figure. During a vehicle collision, the seat belt anchor supports the load of the occupant. Therefore, a tensile load also acts on the seat belt anchor mounting portion 18 in the vehicle frontward and obliquely upward direction (that is, in the direction in which the floor panel 10 is lifted). Along with this, a force also acts on the bead 22 and the like located in the vicinity of the seat belt anchor mounting portion 18. Specifically, a force that pulls in the vehicle inner side direction acts in the order of bead 22a, bead 22b, and bead 22c. That is, a load acts on the bead 22 in the vehicle width direction. In FIG. 2, the direction of the load is indicated by the white arrow 24.

[0017] As shown by the white arrow 24, when a load is applied in the vehicle width direction to the bead 22, the bead 22 is stretched in the vehicle width direction, that is, in the lateral direction of the vertically long shape. The deformation states of the bead 22 and the floor panel 10 are represented by a B-B cross-sectional view obtained by cutting out the rear part of the dots 20 in FIG. 2. More specifically, in FIG. 2, the B-B cross-sectional views are respectively shown above and below the black arrow 26. The upper figure of the black arrow 26 shows the initial state of the floor panel 10, and the lower figure of the black arrow 26 shows the state after the floor panel 10 is deformed by a vehicle collision. As shown in the state after the floor panel 10 is deformed (the lower figure of the black arrow 26), the bead 22 (the three beads 22a, 22b, 22c) is stretched in the lateral direction and its shape has changed. That is, the plurality of beads 22 have a structure similar to a bellows in the lateral direction, are easily elastically deformed, and easily return to their original shape when the load is removed. Due to such characteristics of the plurality of beads 22, it can also be said that the floor panel 10 itself is more easily deformed by providing the beads 22 (that is, by providing the beads 22, the amount of deformation until the floor panel 10 breaks is increased).

[0018] As described above, the three beads 22a, 22b, 22c provided outside the seat belt anchor attachment portion 18 in the vehicle width direction in the floor panel 10 are set such that their lengths become longer towards the outer bead. Therefore, when the vehicle collides, the load applied in the vicinity of the seat belt anchor attachment portion 18 flows outward along the three beads 22a, 22b, 22c. That is, the load applied in the vicinity of the seat belt anchor attachment portion 18 is dispersed. For example, when the vehicle collides, in the lower structure of a conventional vehicle, the dot 20 in the vicinity of the seat belt anchor attachment portion 18 may be broken by a tensile load applied thereto. However, in the structure of this example, since the load spreads to the periphery without concentrating on a specific location, the load applied to each location becomes smaller. In this way, by dispersing the load in the vicinity of the seat belt anchor attachment portion 18, the concentration of stress on the dot 20b can also be suppressed. As a result, the breakage of the dot 20b can be prevented.

[0019] Note that the above description is just an example. In the vehicle underbody structure disclosed in this specification, it suffices if a plurality of beads that are longer the more outward they are located are provided on the outer side in the vehicle width direction of the seat belt anchor mounting portion. Therefore, other configurations may be changed as appropriate. For example, in this example, the lengths of the lower ends of the plurality of beads are set to increase stepwise for the beads toward the outside, and are set such that a straight line can be drawn when the lower ends of the plurality of beads are connected. However, the shape of the lower ends of the beads is not particularly limited as long as the load can be dispersed so as to spread toward the periphery of the beads, particularly toward the outside.

Description of Reference Numerals

[0020] 10 Floor panel, 12 Horizontal surface portion, 14 Inclined surface portion, 16 Rear horizontal surface portion, 18 Seat belt anchor mounting portion, 20(20a, 20b) Dots, 22(22a, 22b, 22c) Beads.

Claims

【Claim 1】 A seat belt anchor mounting portion provided on a floor panel of a vehicle, and a plurality of beads provided on the floor panel, the plurality of beads being provided outside the seat belt anchor mounting portion in the vehicle width direction, and comprising: the plurality of beads extend along the vehicle longitudinal direction and are arranged in the vehicle width direction, and the length of each of the plurality of beads is longer for the bead located outside in the vehicle width direction, characterized by a lower structure of a vehicle.

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