Cross member structure

Abstract

A cross member structure according to the present disclosure is a structure of a cross member (7) that extends in the vehicle width direction along a floor panel (3) of a cargo bed of a vehicle and is joined to the floor panel (3). This structure is provided with: holes (8) formed in prescribed surfaces (13, 14, 15) of the cross member (7); first regions (11) that are regions surrounding the periphery of the holes (8) in the prescribed surfaces (13, 14, 15); and second regions (12) that are regions surrounding the periphery of the first regions (11) in the prescribed surfaces (13, 14, 15). The first regions (11) are formed in a shape recessed deeper on one side in the plate thickness direction of the predetermined surfaces (13, 14, 15) than the second regions (12). The outer edges of the first regions (11) are formed in an elongated shape extending in one direction.

Description

Cross member structure

[0001] This case relates to the structure of a cross member joined to a floor panel of a vehicle bed.

[0002] In vehicles equipped with a cargo bed (cargo box), such as SUVs (sport utility vehicles) and pick-up trucks, a structure in which the floor panel of the cargo bed is reinforced with a cross member has been known. This type of cross member is provided so as to extend along the floor panel in the vehicle width direction and is integrally joined to the floor panel. The entire cargo bed, including the cross member, is mounted on a chassis frame via mounting brackets (see Patent Document 1).

[0003] Japanese Patent Application Publication No. 11-268668

[0004] The plate members that make up the cross member may have holes (openings) such as drainage holes, component mounting holes, and locating holes. However, if the cross member is deflected by a load acting on the floor panel of the cargo bed, stress may be concentrated locally around the hole, resulting in excessive deformation. Such deformation is one of the factors that cause fatigue at the joints (e.g., spot welds) between the cross member and the floor panel. Furthermore, the thinner the plate thickness of the cross member and floor panel, the greater the likelihood of fracture at the joints.

[0005] One of the objectives of the present invention, which was devised in light of the above-mentioned problems, is to provide a cross member structure that can alleviate stress concentration around the hole. However, in addition to this objective, another objective of the present invention is to achieve effects derived from the various configurations shown in the "Description of the Invention" below, which cannot be obtained with conventional technology.

[0006] The disclosed cross member structure can be realized as the following disclosed embodiments (application examples), which solve at least part of the above-mentioned problems. Each of the embodiments from embodiment 2 onwards is an embodiment that can be selected as an additional option, and each of the embodiments from embodiment 2 onwards is an embodiment that can be omitted. None of the embodiments from embodiment 2 onwards discloses an embodiment or configuration that is essential to the present invention.

[0007] Aspect 1. The disclosed cross member structure is a cross member structure that extends in the vehicle width direction along a floor panel of a vehicle cargo bed and is joined to the floor panel. This cross member structure includes a hole formed in a predetermined surface of the cross member, a first region that is an area surrounding the hole on the predetermined surface, and a second region that is an area surrounding the first region on the predetermined surface. The first region is formed in a shape that is recessed toward one side of the predetermined surface in the plate thickness direction relative to the second region, and the outer edge of the first region is formed in an elongated shape that extends in one direction.

[0008] Aspect 2. In an aspect including the above-described aspect 1, it is preferable that the entire first region has a shape recessed toward the one side relative to the second region. Aspect 3. In an aspect including the above-described aspect 1, it is preferable that the outer edge of the first region has an elliptical shape or a track shape.

[0009] Aspect 4. In the aspect including the above-mentioned aspect 1, it is preferable that the outer edge of the first region is formed in an elongated shape in the vehicle width direction of the vehicle. Aspect 5. In the aspect including the above-mentioned aspect 1, it is preferable that the predetermined surface forms the underside of the cross member.

[0010] Aspect 6. In an aspect including the above aspect 1, it is preferable that the hole, the first region, and the second region are located in a center portion of the cross member in the vehicle width direction. Aspect 7. In an aspect including the above aspect 1, it is preferable that the second region is formed in a shape that protrudes further toward the other side of the predetermined surface in the plate thickness direction than the predetermined surface. Aspect 8. In an aspect including the above aspect 1, it is preferable that the cross member is located in a position adjacent to a wheel house of the vehicle.

[0011] The disclosed cross member structure can reduce stress concentration around the cross member holes and suppress deformation of the cross member. This reduces fatigue at the joint between the cross member and the floor panel. It also suppresses deformation of the cross member and floor panel, improving vibration damping.

[0012] 1 is a perspective view of a vehicle to which a cross member structure according to an embodiment is applied. (A) is a bottom view showing the vehicle's cargo bed as viewed from below, and (B) is a longitudinal cross-sectional view of the cargo bed and cross member (a cross-sectional view taken along line A-A in FIG. 2A). It is a perspective view showing the cross member as viewed from below. It is an enlarged perspective view of the main portion of FIG. 3. (A) is a front view of a first reinforcing portion (a bottom view of the cross member), (B) is a cross-sectional view taken along line B-B in FIG. 5A, and (C) is a cross-sectional view taken along line C-C in FIG. 5A. (A) is a front view of a second reinforcing portion (a bottom view of the cross member), (B) is a cross-sectional view taken along line D-D in FIG. 6A, and (C) is a cross-sectional view taken along line E-E in FIG. 6A. (A) to (H) are front views of a first reinforcing portion (a bottom view of the cross member) according to a modified example. (A) and (B) are longitudinal cross-sectional views of a first reinforcing portion according to a modified example.

[0013] The cross member structure according to the present invention is applied to the cargo bed of a vehicle shown in the following embodiment. The vehicle is an SUV, truck, pick-up truck, or other vehicle equipped with a cargo bed. The cargo bed here includes a cargo box or a luggage compartment. The cargo bed may be open to the outside or may be a closed space. Regarding the definition of directions in this embodiment, the front-to-rear direction is defined based on the forward and backward direction of the vehicle, and the left-to-right direction (vehicle width direction) is defined based on the front-to-rear direction. The up-to-down direction is defined based on the state in which the vehicle is stopped on a flat road surface.

[0014] [1. Structure] Figure 1 is a perspective view of a vehicle 1 to which a cross member structure according to an embodiment is applied. The vehicle 1 has a ladder frame-type chassis structure. A ladder frame is a ladder-shaped frame formed by combining a pair of left and right side frames extending in the front-to-rear direction with a cross frame connecting the side frames in the vehicle width direction. The vehicle 1 is also provided with a cargo bed 2 mounted on the ladder frame. The cargo bed 2 is formed in the shape of a container with an open top, and is located behind the vehicle interior (cabin) in which occupants sit.

[0015] As shown in FIG. 1 , the cargo bed 2 includes a floor panel 3 forming its bottom surface (floor surface), wall-like side gates erected at the left and right ends of the cargo bed 2, and a wall-like rear gate erected at the rear end of the cargo bed 2. As shown in FIG. 1 , the side gates are formed by joining an outer panel 6 that forms the exterior of the cargo bed 2 with an inner panel 5 that is disposed inside the outer panel 6 at a predetermined distance. Similarly, the rear gate is formed by joining the outer panel 6 with the inner panel 5. Support structures such as struts and posts may be disposed inside the side gates and rear gate (in the space between the outer panel 6 and the inner panel 5).

[0016] Each of the pair of left and right side gates has a wheel well 4 formed by an inner panel 5 that bulges inward of the cargo bed 2 near the midpoint in the vehicle's fore-and-aft direction. The rear tires are located below the wheel well 4. Because there is insufficient space inside the side gate near the wheel well 4, support structures such as struts and posts are often not formed. In this case, the rigidity near the wheel well 4 may be lower than other parts of the side gate.

[0017] The floor panel 3 is a flat portion that forms the bottom surface of the cargo bed 2. The plate surface of the floor panel 3 is formed with uneven shapes and ribs to increase surface rigidity. In addition, a cross member 7 (cross sill) is provided on the underside of the floor panel 3 as a reinforcing member. The cross member 7 extends in the vehicle width direction along the floor panel 3 of the cargo bed 2 and is joined to the underside of the floor panel 3.

[0018] FIG. 2(A) is a bottom view showing the cargo bed 2 as viewed from below the vehicle 1, and FIG. 2(B) is a longitudinal cross-sectional view (A-A cross-sectional view of FIG. 2(A)) of the cargo bed 2 and cross member 7. FIG. 3 is a perspective view showing the cross member 7 as viewed from below the vehicle 1, and FIG. 4 is an enlarged perspective view of a main portion thereof. The floor panel 3 of this embodiment has multiple ribs extending in the fore-and-aft direction of the vehicle. The cross members 7 of this embodiment are provided at multiple positions spaced apart in the fore-and-aft direction of the vehicle on the underside of the floor panel 3. The cross members 7 are arranged substantially parallel to one another.

[0019] 2(A) shows three cross members 7 that reinforce the portion of the floor panel 3 sandwiched between the pair of left and right wheel houses 4, one cross member 7 that reinforces the floor panel 3 forward of the wheel houses 4, and one cross member 7 that reinforces the floor panel 3 rearward of the wheel houses 4. Each cross member 7 may be formed in a curved shape so that both ends in the vehicle width direction are joined to the outer surfaces of the inner panel 5 and the wheel houses 4, as shown in FIG.

[0020] Each cross member 7 has a rail-like shape with a hat-shaped cross section. The cross member 7 shown in Figure 4 has a lower surface 13, a pair of side surfaces 14, and a pair of flanges 15. The lower surface 13 is a planar portion corresponding to the top of the hat shape (the lower bottom portion in Figure 4), and is the portion that forms the lowest part of the cross member 7. The side surfaces 14 are planar portions that extend upward from both end edges of the lower surface 13 in the vehicle's fore-and-aft direction. The flanges 15 are planar portions that extend from the upper edges of the side surfaces 14 approximately parallel to the lower surface 13, and are fixed to the floor panel 3 by fasteners, spot welding, etc.

[0021] As shown in Figure 4, holes 8 are provided in the cross member 7. The holes 8 are openings such as drainage holes, component mounting holes, positioning holes, and painting holes. The shape of the holes 8 is determined depending on the application and purpose, and may be circular, elliptical, polygonal, star-shaped, slit-shaped, or the like. The number and positions of the holes 8 are also determined depending on the application and purpose. The cross member 7 shown in Figure 4 has multiple holes 8 on each of the underside 13, side surfaces 14, and flange 15.

[0022] In the example shown in Fig. 2, holes 8 are arranged in three locations on the underside 13 of each cross member 7: in the center in the vehicle width direction, on the left side thereof, and on the right side thereof. These holes 8 are arranged, for example, in a straight line in the fore-and-aft direction of the vehicle. In the example shown in Fig. 4, multiple holes 8 are arranged on each of the side surfaces 14 and flanges 15 so that their positions in the vehicle width direction differ from those of the holes 8 formed on the underside 13.

[0023] A reinforcing structure for reinforcing the plate surface can be applied around each hole 8. In this embodiment, the cross member 7 is provided with a first reinforcing portion 9A and a second reinforcing portion 9B as reinforcing portions 9 for reinforcing the areas around the holes 8. FIGS. 5A to 5C are diagrams showing the configuration of the first reinforcing portion 9A, and FIGS. 6A to 6C are diagrams showing the configuration of the second reinforcing portion 9B. It is not necessary to provide reinforcing portions 9 around all holes 8; for example, reinforcing portions 9 may be provided only in areas where strength or rigidity is critical.

[0024] The first reinforcing portion 9A includes a first region 11, which is a region surrounding the periphery of the hole 8, and a second region 12, which is a region surrounding the periphery of the first region 11, on a predetermined surface (the lower surface 13 in FIGS. 5(A) to 5(C)). The predetermined surface here refers to the surface on which the hole 8 is formed. In the following description, the lower surface 13 shown in FIGS. 5(A) to 5(C) is the predetermined surface. Note that, because the hole 8 is also formed on the side surface 14 and the flange 15, the predetermined surface (lower surface 13) in the following description may be understood as either the side surface 14 or the flange 15.

[0025] The first region 11 is formed in a shape recessed toward one side of the predetermined surface (lower surface 13) in the plate thickness direction (the lower side in FIGS. 5B and 5C ) relative to the second region 12. The first region 11 may be recessed entirely toward one side of the second region 12, or may be recessed partially toward one side of the second region 12. Furthermore, the first region 11 may be recessed almost entirely uniformly (a planar shape with a constant recess dimension) or gradually recessed (a curved shape with a gradually changing recess dimension). By making the first region 11 recessed relative to the second region 12, the second moment of area in the plate thickness direction at the predetermined surface (lower surface 13) increases, and bending rigidity is enhanced.

[0026] The outer edge of the first region 11 is formed in an elongated shape extending in one direction. That is, the shape of the region surrounded by the boundary between the first region 11 and the second region 12 is formed in a non-circular shape. The term "elongated shape (non-circular shape)" here refers to a shape in which, when two mutually perpendicular X- and Y-axes are defined on a predetermined surface (lower surface 13), the maximum dimension in the X-axis direction is greater than the maximum dimension in the Y-axis direction. Specifically, this includes elliptical shapes, track shapes, egg shapes, rectangular shapes, diamond shapes, polygonal shapes, etc. By forming the outer edge of the first region 11 in an elongated shape, stress distribution around the hole 8 is more easily dispersed in one direction, thereby mitigating local stress concentration. The outer edge of the first region 11 shown in FIG. 5(A) is a track shape formed by smoothly connecting two semicircles with two parallel lines.

[0027] The outer edge of the first region 11 shown in Fig. 5(A) is formed in an elongated shape extending in the vehicle width direction of the vehicle 1. In other words, the outer edge of the first region 11 shown in Fig. 5(A) is formed in an elongated shape extending along the vehicle width direction, which is the extension direction of the cross member 7. This makes it easier to distribute stress concentrated at positions around the hole 8 adjacent in the vehicle fore-and-aft direction due to flexural deformation of the cross member 7 in the vehicle width direction, and efficiently alleviates local stress concentration.

[0028] The second region 12 is formed in a shape that protrudes at least further in the thickness direction than the first region 11 (upper side in FIGS. 5B and 5C). In this embodiment, the second region 12 is formed in a shape that protrudes further in the thickness direction than the predetermined surface (lower surface 13) (upper side in FIGS. 5B and 5C). This further increases the second moment of area in the thickness direction at the predetermined surface (lower surface 13), thereby increasing bending rigidity. The second region 12 may be formed in a shape that protrudes uniformly over almost the entire surface (a planar shape with a constant protrusion dimension), or may be formed in a shape that protrudes gradually (a curved shape with a gradually changing protrusion dimension).

[0029] By making the second region 12 protrude toward the other side in the plate thickness direction, the downward protrusion dimension of the first region 11 from the predetermined surface (lower surface 13) is reduced. Therefore, for example, when another component (not shown) is disposed below the cross member 7, interference between the cross member 7 and the other component is prevented. Note that with regard to the relationship in size between the protrusion dimension of the second region 12 from the predetermined surface (lower surface 13) and the recess dimension of the first region 11 from the second region 12, the former may be set larger than the latter, the former may be set smaller than the latter, or the former and the latter may be set to the same value.

[0030] The outer edge of the second region 12 may be formed in an elongated shape extending in one direction, similar to the first region 11. Alternatively, it may be formed in a square or circular shape. The outer edge of the second region 12 shown in Fig. 5(A) is elongated in the vehicle width direction of the vehicle 1, forming a rectangular shape. This makes it easier to distribute stress acting on the first region 11 in the vehicle width direction in response to flexural deformation of the cross member 7, and efficiently alleviates local stress concentration.

[0031] Like the first reinforcing part 9A, the second reinforcing part 9B also includes a first region 11, which is a region surrounding the periphery of the hole 8, and a second region 12, which is a region surrounding the periphery of the first region 11, on a predetermined surface (the lower surface 13 in FIGS. 6A to 6C). However, in the second reinforcing part 9B, the second region 12 is provided so as to be flush with the predetermined surface (the lower surface 13). If the second region 12 and the lower surface 13 are considered to be the same, the first region 11 is formed in a shape recessed toward one side of the predetermined surface (the lower surface 13) in the plate thickness direction (the lower side in FIGS. 6B and 6C). This increases the second moment of area in the plate thickness direction on the predetermined surface (the lower surface 13), thereby increasing bending rigidity.

[0032] In the cross-sectional shape of the cross member 7 shown in Figure 5(C), when water, coating liquid, etc. accumulates inside the cross member 7, the second region 12 acts like a levee surrounding the hole 8, which may result in poor drainage and liquid drainage. On the other hand, the cross-sectional shape of the cross member 7 shown in Figure 6(C) provides good drainage and liquid drainage. Therefore, it is preferable to apply the second reinforcing portion 9B rather than the first reinforcing portion 9A around the drain holes and coating holes.

[0033] With respect to the position of the hole 8 in the vehicle width direction, the central portion of the cross member 7 in the vehicle width direction is subject to greater flexural deformation than the left and right ends in the vehicle width direction. Therefore, it is preferable to apply reinforcing portions 9 such as a first reinforcing portion 9A and a second reinforcing portion 9B around the hole 8 provided in the central portion of the cross member 7 in the vehicle width direction. On the other hand, reinforcing portions 9 do not need to be applied to the holes 8 provided in the left and right ends in the vehicle width direction of the cross member 7.

[0034] [2. Effects] (1) The cross member structure according to the present invention is a cross member 7 structure that extends in the vehicle width direction along a floor panel 3 of a cargo bed 2 of a vehicle 1 and is joined to the floor panel 3. This structure includes a hole 8 formed in a predetermined surface of the cross member 7, a first region 11 that is an area surrounding the periphery of the hole 8 on the predetermined surface, and a second region 12 that is an area surrounding the periphery of the first region 11 on the predetermined surface. The first region 11 is formed in a shape that is recessed toward one side of the predetermined surface in the plate thickness direction relative to the second region 12. Furthermore, the outer edge of the first region 11 is formed in an elongated shape that extends in one direction.

[0035] This configuration allows the stress distribution around the hole 8 to be dispersed in one direction, mitigating local stress concentration. This suppresses deformation of the cross member 7 and reduces fatigue at the joint between the cross member 7 and the floor panel 3. Furthermore, even if the cross member 7 and the floor panel 3 have small plate thicknesses, the possibility of fracture at the joint can be reduced. Furthermore, since the rigidity of the cross member 7 is improved, deformation of the cross member 7 and the floor panel 3 can be suppressed, improving vibration damping and suppressing, for example, differential noise and vibration.

[0036] (2) The first region 11 may be formed in a shape that is recessed entirely to one side (e.g., downward) relative to the second region 12. This configuration increases the moment of inertia in the thickness direction in a predetermined plane compared to when only a portion of the first region 11 is recessed, thereby enhancing the effect of alleviating stress concentration around the hole 8 of the cross member 7.

[0037] (3) The first region 11 may have an outer edge formed in an elliptical or track shape, as shown in FIG. 5A , for example. This configuration allows the first region 11 to bear stress over a wide range in the major axis direction, thereby reducing local stress concentration in the major axis direction compared to, for example, a case in which the outer edge of the first region 11 is a perfect circle. Furthermore, this simple shape can enhance the effect of reducing stress concentration around the hole 8. Furthermore, the processing for forming the first region 11 is relatively easy, and the effect of reducing stress concentration can be enhanced while reducing the manufacturing time and manufacturing costs.

[0038] (4) As shown in Fig. 5A, the outer edge of the first region 11 can be formed in a narrow shape extending in the width direction of the vehicle 1. This configuration allows the stress that tends to concentrate around the hole 8 in the fore-and-aft direction of the vehicle due to the flexural deformation of the cross member 7 to be efficiently dispersed in the width direction of the vehicle. This reduces the localized stress concentration.

[0039] (5) As shown in Figures 5 and 6, the predetermined surface on which the hole 8 is formed is, for example, the underside 13 of the cross member 7. In this way, by providing the reinforcing portion 9 (first region 11 and second region 12) around the hole 8 formed on the underside 13 of the cross member 7, the effect of alleviating stress concentration during downward bending deformation of the cross member 7 can be enhanced. Note that deformation of the cross member 7 occurs not only on the underside 13 but also on the side surfaces 14 and flanges 15. Therefore, even when the reinforcing portion 9 (first region 11 and second region 12) is provided around the hole 8 formed on the side surfaces 14 and flanges 15, the effect of alleviating stress concentration can be enhanced.

[0040] (6) As shown in Figures 2 and 3, a hole 8 and a reinforcing portion 9 (first region 11 and second region 12) are provided in the center of the cross member 7 in the vehicle width direction. In this way, by providing the reinforcing portion 9 (first region 11 and second region 12) around the hole 8 formed in the portion where bending deformation is large, the effect of mitigating stress concentration in bending deformation can be further enhanced.

[0041] (7) As shown in Figures 5(B) and 5(C), the second region 12 can be formed in a shape that protrudes from a predetermined surface (e.g., the lower surface 13) toward the other side (e.g., the upper side) in the plate thickness direction of the predetermined surface. This configuration can further increase the second moment of area in the plate thickness direction at the predetermined surface (lower surface 13), thereby increasing the bending rigidity of the cross member 7. In addition, the downward protrusion dimension of the first region 11 from the predetermined surface (lower surface 13) can be reduced, preventing interference between the cross member 7 and other components.

[0042] (8) As shown in Figures 2 and 3, the cross member 7 can be disposed adjacent to the wheel house 4 of the vehicle 1. In this way, by providing the reinforcing portion 9 (first region 11 and second region 12) for the hole 8 of the cross member 7 disposed near the wheel house 4 where the rigidity of the side gate tends to be low, the effect of alleviating stress concentration can be enhanced.

[0043] [3. Other] The above-described embodiments are merely illustrative and are not intended to exclude various modifications or applications of techniques not explicitly described in the present embodiments. Each configuration of the present embodiments can be modified in various ways without departing from the spirit of the present embodiments. Furthermore, each configuration of the present embodiments can be selected as needed, or can be appropriately combined with various configurations included in known techniques.

[0044] In the above-described embodiment, the outer edge of the first region 11 is shaped like a track, but the shape of the outer edge of the first region 11 is not limited to this. For example, the outer edge of the first region 11 may be elliptical as shown in Fig. 7(A) or rectangular as shown in Fig. 7(B). By making the outer edge of the first region 11 at least elongated and extending in one direction, the same effects as those of the above-described embodiment can be achieved.

[0045] In the above-described embodiment, the first region 11 is entirely recessed toward one side of the second region 12, but the shape of the first region 11 is not limited to this. For example, as shown in Fig. 7(C), the second region 12 may be partially recessed into the first region 11, or as shown in Fig. 7(D), a portion of the first region 11 may remain unrecessed.

[0046] In the above-described embodiment, the outer edge of the second region 12 is rectangular, but the shape of the outer edge of the second region 12 is not limited to this. For example, the outer edge of the second region 12 may be elliptical as shown in Fig. 7(E), or may be track-shaped as shown in Fig. 7(F).

[0047] In the above-described embodiment, the outer edges of the first region 11 and the second region 12 are formed in a narrow shape extending in the vehicle width direction of the vehicle 1. That is, the direction in which the outer edges of the first region 11 and the second region 12 extend is the vehicle width direction. However, the "one direction" referred to here is not limited to the vehicle width direction. For example, as shown in FIG. 7(G), the outer edges of the first region 11 and the second region 12 may be formed in a narrow shape extending in the vehicle front-rear direction. Alternatively, as shown in FIG. 7(H), the outer edges may be formed in a narrow shape extending in a diagonal direction (for example, a diamond shape or a parallelogram shape).

[0048] 5B and 5C, the first region 11 has a uniformly recessed shape (a planar shape with a constant recess size) across the entire region, but the cross-sectional shape of the first region 11 is not limited to this. For example, the first region 11 may have a gradually recessed shape (a curved surface shape with a gradually changing recess size) as shown in FIG.

[0049] Similarly, in the above-described embodiment, as shown in Figures 5(B) and 5(C), the second region 12 has a shape that protrudes uniformly over almost the entirety (a planar shape with a constant protrusion dimension), but the cross-sectional shape of the second region 12 is not limited to this. For example, as shown in Figure 8(B), the second region 12 may have a shape that protrudes gradually (a curved shape with a gradually changing protrusion dimension).

[0050] In the above embodiment, as shown in Figure 2(A), the layout of the holes 8 provided on the underside 13 of the cross member 7 is aligned in the fore-and-aft direction of the vehicle, but the layout of the holes 8 is not limited to this. The holes 8 provided on each cross member 7 do not need to be aligned in the fore-and-aft direction of the vehicle, and even if they are aligned, the row does not need to be centered in the vehicle width direction, and may be offset to the left or right. The layout of the holes 8 may be set as appropriate depending on the conditions of the vehicle 1 and the cargo bed 2.

[0051] The present invention is applicable to the manufacturing industry of cross members joined to floor panels of vehicle cargo beds, and to the manufacturing industry of vehicles equipped with such cross members.

[0052] REFERENCE SIGNS LIST 1 vehicle 2 cargo bed 3 floor panel 4 wheel house 5 inner panel 6 outer panel 7 cross member 8 hole 9 reinforcing portion 9A first reinforcing portion 9B second reinforcing portion 11 first region 12 second region 13 underside (predetermined surface) 14 side surface (predetermined surface) 15 flange (predetermined surface)

Claims

1. A cross member structure extending in the vehicle width direction along a floor panel of a vehicle bed and joined to the floor panel, a hole formed on a predetermined surface of the cross member; a first region that is a region surrounding the hole on the predetermined surface; a second region that is a region surrounding the first region on the predetermined plane, The first region is formed in a shape recessed toward one side of the predetermined surface in the plate thickness direction relative to the second region, The outer edge of the first region is formed in an elongated shape extending in one direction, The second region is formed in a shape that protrudes from the predetermined surface to the other side in the plate thickness direction of the predetermined surface. A cross member structure characterized by:

2. The first region has a shape recessed toward the one side relative to the second region. The cross member structure according to claim 1 .

3. The outer edge of the first region is elliptical or track-shaped. The cross member structure according to claim 1 .

4. The outer edge of the first region is formed in an elongated shape in the vehicle width direction. The cross member structure according to claim 1 .

5. The predetermined surface forms the lower surface of the cross member. The cross member structure according to claim 1 .

6. The hole, the first region, and the second region are disposed in the center of the cross member in the vehicle width direction. The cross member structure according to claim 1 .

7. The cross member is disposed adjacent to a wheel house of the vehicle. The cross member structure according to claim 1 .