Vehicle rear structure

Abstract

To provide a vehicle rear structure capable of effectively preventing, with a simple construction, breakage of a panel material.SOLUTION: A vehicle rear structure includes: a lower back panel 14 that defines lower edges of a back door opening 12 of a vehicle 10; housing panels 18 that are joined to an end in a vehicle width direction of, and upper edges of the lower back panel 14 and that extend upward. One or more beads 24 are formed elongated in the vehicle width direction in a part below weld points 22 that join the housing panel 18, of the lower back panel 14.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present specification discloses a rear structure of a vehicle having a back door opening. [Background technology]

[0002] Vehicles with a back door opening at the rear of the vehicle have been known for some time. The lower edge of the back door opening is defined by a panel material called a lower back panel. A housing panel is joined to the upper end of the lower back panel in the vehicle width direction. The housing panel is a panel material to which a lamp unit including a taillight is attached.

[0003] When a vehicle travels over an uneven surface, road force is transmitted to the lower back panel via the rear suspension. In this case, an upward or downward load acts on the lower back panel, placing a large load on the weld between the lower back panel and the housing panel. This can lead to cracks originating from the weld in the lower back panel, the housing panel, or both.

[0004] Therefore, several technologies have been proposed to prevent damage to panel materials in the rear of a vehicle. For example, Patent Document 1 discloses a rear vehicle body structure including a rear pillar that forms the side edge of a tailgate opening and an extension panel that forms the lower corner of the tailgate opening. In Patent Document 1, the rear pillar and the extension panel are connected, and a convex bead extending in the vertical direction is formed at the lower end of the rear pillar and the upper end of the extension panel so as to straddle both. This configuration can improve the rigidity of the joint between the rear pillar and the extension panel to some extent, thereby preventing damage to these parts to some extent. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-236552 Summary of the Invention [Problem to be solved by the invention]

[0006] However, in Patent Document 1, it is necessary to provide an extension panel separate from the housing panel, which increases the number of parts and vehicle weight. Furthermore, in Patent Document 1, a convex portion is formed that straddles both the rear pillar and the extension panel. In this case, it is necessary to maintain high positional accuracy between the convex portion formed on the rear pillar and the convex portion formed on the extension panel, which can easily complicate the vehicle manufacturing process.

[0007] Therefore, this specification discloses a vehicle rear structure that can effectively prevent damage to panel materials with a simple configuration. [Means for solving the problem]

[0008] The vehicle rear structure disclosed in this specification comprises a lower back panel that defines the lower edge of the vehicle's tailgate opening, and a housing panel that is joined to the vehicle width direction end and upper end of the lower back panel and extends upward, and is characterized in that one or more beads that are long in the vehicle width direction are formed in the lower portion of the lower back panel below the welding point with the housing panel.

[0009] In this case, a plurality of the beads may be formed at intervals in the vertical direction.

[0010] The depth of the bead may be five times or more the thickness of the lower back panel, and the entrance width, which is the vertical dimension of the entrance of the bead, may be smaller than the depth. [Effects of the Invention]

[0011] The technology disclosed in this specification allows road input to be absorbed by the deformation of the bead, effectively suppressing cracks in the lower back panel or housing panel that originate at the weld point. In addition, the bead is contained within the lower back panel, simplifying the configuration of the lower back panel and housing panel. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a schematic perspective view of a vehicle. [Figure 2] FIG. 2 is a rear view of part A in FIG. 1. [Figure 3] FIG. 3 is a schematic cross-sectional view taken along line BB in FIG. 2. [Figure 4] FIG. 10 is a cross-sectional view showing the state of the lower back panel when subjected to road surface input. [Figure 5] FIG. 10 is a diagram showing another example of a bead. DETAILED DESCRIPTION OF THE INVENTION

[0013] The vehicle rear structure will be described below with reference to the drawings. Fig. 1 is a schematic perspective view of a vehicle 10. Fig. 2 is a view of the area around part A in Fig. 1 as seen from behind the vehicle 10. Fig. 3 is a schematic cross-sectional view taken along line BB in Fig. 2. In each of the following figures, "Fr", "Up", and "Rh" indicate the front, top, and right sides of the vehicle, respectively.

[0014] A back door opening 12 is formed in the rear wall of the vehicle 10. The back door opening 12 is an opening that connects the luggage space of the vehicle 10 to the outside of the vehicle, and is an opening that is covered by a back door (not shown) that can be opened and closed freely. The side edges of the back door opening 12 are defined by rear pillars 16. The rear pillars 16 are skeletal members that are arranged at the boundaries between the side walls and the rear wall of the vehicle 10, and are skeletal members that are long in the vertical direction of the vehicle.

[0015] The lower edge of the tailgate opening 12 is defined by a lower back panel 14. The lower back panel 14 is a panel member that is elongated in the vehicle width direction. As shown in Fig. 3, the lower back panel 14 has a generally hat-shaped cross section that opens toward the front of the vehicle. In other words, the lower back panel 14 has a rear wall 14a that corresponds to the top surface of the hat, a standing wall 14b that corresponds to the circumferential surface of the hat, and an upper flange wall 14c and a lower flange wall 14d that correspond to the flange portion of the hat.

[0016] A lower back clean force (hereinafter referred to as "lower back R / F") 20 is joined to the lower back panel 14. The lower back R / F 20 is located forward of the lower back panel 14 in the vehicle front-to-rear direction and faces the lower back panel 14 in the vehicle longitudinal direction. The lower back R / F 20 has a generally hat-shaped cross section that opens toward the rear of the vehicle. Flange walls 20c, 20d of this lower back R / F 20 and flange walls 14c, 14d of the lower back panel 14 are joined to each other. This forms a closed space 21 that is elongated in the vehicle width direction.

[0017] A housing panel 18 is provided between the lower back panel 14 and the rear pillar 16. The housing panel 18 is a panel material to which a lamp unit (not shown) including a taillight or the like is attached. Although the housing panel 18 is illustrated in FIGS. 1 to 3 as having a simple shape with few protrusions and recesses, the actual housing panel 18 has many more protrusions and recesses formed therein according to the shape of the lamp unit.

[0018] The housing panel 18 is joined to the end of the lower back panel 14 in the vehicle width direction. Specifically, as shown in Fig. 3, the lower end of the housing panel 18, the upper end of the lower back panel 14 (i.e., upper flange wall 14c), and the upper end of the lower back R / F 20 (i.e., upper flange wall 20c) are spot welded together while overlapping each other in the thickness direction. A plurality of spot welds are performed along the upper edge of the lower back panel 14. Black circles in Fig. 2 and black ovals in Fig. 3 indicate weld points 22 formed by spot welding.

[0019] 2 and 3, a bead 24 that protrudes rearward and is elongated in the vehicle width direction is formed on the rear wall 14a of the lower back panel 14 below the welding point 22. In this example, two such beads 24 are provided spaced apart in the vertical direction of the vehicle. Note that in FIG. 3, the bead 24 is illustrated larger than its actual size for ease of understanding. The reason for providing such a bead 24 will be explained.

[0020] A rear suspension (not shown) is provided at the rear of the vehicle 10. The rear suspension absorbs vibrations of the rear wheels that occur as the vehicle 10 travels. However, the rear suspension cannot absorb all of the vibrations, and some of the vibrations are transmitted to the vehicle body via the rear suspension. Hereinafter, the vibrations transmitted to the vehicle body will be referred to as "road input." This road input is also transmitted to the lower back panel 14 via the vehicle body. In other words, as the vehicle 10 travels, the lower back panel 14 also vibrates in the up-and-down direction. When the lower back panel 14 vibrates in the up-and-down direction, a large stress may be applied to the weld 22 between the lower back panel 14 and the housing panel 18. This stress may cause cracks to form in the lower back panel 14, the housing panel 18, or both, starting from the weld 22.

[0021] In this example, in order to prevent such damage to the lower back panel 14 and the housing panel 18, multiple beads 24 are provided on the lower back panel 14. By providing such beads 24, road input can be absorbed by deformation of the beads 24, and the load acting on the weld points 22 can be reduced.

[0022] More specifically, each bead 24 has a pair of standing walls 30 that rise from the lower back panel 14 toward the rear of the vehicle, and a connecting wall 32 that connects the pair of standing walls 30. Hereinafter, the vertical distance from the base of one standing wall 30 to the base of the other standing wall 30 will be referred to as the "entrance width H of the bead 24."

[0023] When an upward load is applied to the lower back panel 14, the vertical wall 30 tilts or bends, as shown in FIG. 4 , so that the entrance width H of the bead 24 decreases. From another perspective, when an upward load is applied to the lower back panel 14, the vertical dimension of the multiple beads 24 arranged in a bellows-like shape contracts. When a downward load is applied to the lower back panel 14, the vertical dimension of the multiple beads 24 arranged in a bellows-like shape expands. Because the vertical load is absorbed by the deformation of the multiple beads 24, the transmission of the vertical load to the weld point 22 is effectively suppressed. As a result, the occurrence of cracks originating from the weld point 22 is effectively suppressed.

[0024] To prevent cracks in the lower back panel 14 and the housing panel 18, it is possible to add a reinforcing panel called an extension panel. However, this would increase the number of parts, leading to other problems such as increased costs and vehicle weight. It is also possible to form a vertical bead extending vertically across both the lower back panel 14 and the housing panel 18. Providing such a vertical bead may improve the rigidity of the lower back panel 14 and the housing panel 18, potentially effectively preventing damage to these panels. However, in this case, it is necessary to align the lower end position of the vertical bead formed on the housing panel 18 with the upper end position of the vertical bead formed on the lower back panel 14. However, aligning the positions of the vertical beads formed on the two panels 18, 14, which are completely separate components, requires high molding precision when the panels 18, 14 are press-formed and high assembly precision when they are assembled to the vehicle body. As a result, when a vertical bead is provided across both the housing panel 18 and the lower back panel 14, another problem arises in that the molding and assembling processes become complicated.

[0025] On the one hand, the bead 24 provided in this example is completed within the lower back panel 14 and does not reach the housing panel 18. Therefore, according to this example, there is no need to maintain high positional accuracy of the bead 24, and the molding and assembly processes of the lower back panel 14 and the housing panel 18 can be simplified. Further, according to this example, since no separate member such as an extension panel is required, an increase in cost and an increase in vehicle weight can be effectively suppressed.

[0026] By the way, in this example, when the vertical wall 30 of the bead 24 deflects or tilts, the entrance width H of the bead 24 changes, and thereby, the road surface input is absorbed. Therefore, the bead 24 is required to have a shape in which the vertical wall 30 can deflect or tilt relatively easily. In order to meet such a requirement, the depth D of the bead 24 has to be made somewhat deeper. Thus, in this example, the depth D of the bead 24 is set to be 5 times or more the plate thickness t of the lower back panel 14.

[0027] On the other hand, if the depth D of the bead 24 is excessively larger than the entrance width H of the bead 24, press molding for forming the bead 24 becomes difficult. Therefore, in this example, the depth D of the bead 24 is made smaller than the entrance width H of the bead 24. That is, the bead 24 in this example has a shape that satisfies D≧5×t and D<H. By adopting such a configuration, the bead 24 that can effectively absorb the road surface input can be easily molded. However, the dimensional relationships exemplified here are just examples and may be changed as appropriate. Therefore, naturally, D<5×t may be acceptable, or D≧H may be acceptable.

[0028] Also, the vehicle width direction range W of the bead 24 is not particularly limited. However, in order to reduce the load applied to the plurality of weld points 22, it is desirable that the vehicle width direction range W of the bead 24 is a range that can cover the plurality of weld points 22. For example, the vehicle width direction range W of the bead 24 may be a size that can cover the middle 1 / 3 range of the vehicle width direction range Wh of the housing panel 18.

[0029] 3, the lower back panel 14 of this example has a generally hat-shaped cross section that opens toward the front of the vehicle. The bead 24 may be formed on a surface of the lower back panel 14 below the welding point 22 and generally parallel to the vertical plane. Therefore, the bead 24 may be formed on the upper flange wall 14c or the lower flange wall 14d instead of or in addition to the rear wall 14a.

[0030] In the above description, two beads 24 are provided spaced apart in the vertical direction, but the number of beads 24 may be changed as appropriate. For example, only one bead 24 may be provided, or three or more beads 24 may be provided. In the above description, the bead 24 protrudes rearward from the vehicle, but the bead 24 may protrude forward from the vehicle as long as it can absorb road surface input. Furthermore, as shown in FIG. 5, one lower back panel 14 may be provided with both a bead 24a protruding rearward from the vehicle 10 and a bead 24b protruding forward from the vehicle 10. In addition, the bead 24 is not limited to a linear shape, and may have a curved or bent shape in rear view, as long as it is elongated in the vehicle width direction. [Explanation of symbols]

[0031] 10 vehicle, 12 back door opening, 14 panel, 14 lower back panel, 16 rear pillar, 18 housing panel, 18 panel, 20 lower back R / F, 21 enclosed space, 22 weld point, 24 bead, 30 standing wall, 32 connecting wall.

Claims

1. a lower back panel that defines a lower edge of a back door opening of the vehicle; a housing panel joined to an upper end of the lower back panel in the vehicle width direction and extending upward; and one or more long beads are formed in the vehicle width direction in a lower portion of the lower back panel in the vehicle up-down direction of a welding point between the lower back panel and the housing panel. A vehicle rear structure characterized by:

2. 2. The vehicle rear structure according to claim 1, A vehicle rear structure characterized in that a plurality of the beads are formed at intervals in the vertical direction.

3. 3. The vehicle rear structure according to claim 1 or 2, The depth of the bead is five times or more the plate thickness of the lower back panel, The inlet width, which is the vertical dimension of the inlet of the bead, is smaller than the depth. A vehicle rear structure characterized by:

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