Rear bumper structure

Abstract

A bumper reinforcement (20) comprises a frame member (21) having an open cross section that opens upward over the entire length, a center bracket (22) that is fixed to a front plate (21b) and a rear plate (21c) of the frame member (21) below a first step (11) and that supports the first step (11), and a support member (23) that supports a second step (12) and has leg plates (23a, 23b) fixed to the front plate (21b) and the rear plate (21c) at positions near one side of the vehicle width direction with respect to the center bracket (22).

Description

[Technical Field]

[0001] The present invention relates to a rear bumper structure provided on a vehicle. [Background technology]

[0002] Generally, a rear bumper structure includes a rear bumper fascia disposed at the rear end of a vehicle and a bumper reinforcement disposed inside the rear bumper fascia. The bumper reinforcement is connected to a side member of the vehicle body. Conventionally, the bumper reinforcement is configured by combining a frame member that is elongated in the vehicle width direction with multiple members.

[0003] For example, in the rear bumper structure disclosed in Patent Document 1, the bumper reinforcement is composed of a groove-shaped frame member that extends in the vehicle width direction and is open to the front side, and an arm fixed to the front end of this frame member. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 7-117591 Summary of the Invention [Problem to be solved by the invention]

[0005] In recent years, in order to improve the ease of access to the rear of the vehicle, a first step portion is provided in the center of the rear bumper fascia in the vehicle width direction, and higher second step portions are provided on both sides of the rear bumper fascia in the vehicle width direction, with these step portions being structured so that people can step on them. When this type of rear bumper fascia is used, it is preferable to support the first and second step portions, which are subject to tread load, but the rear bumper structure of Patent Document 1 does not take into consideration supporting the rear bumper fascia. When tread load acts on the upper plate portion of the groove-shaped frame member that is open forward, the upper plate portion is prone to bending, raising concerns about insufficient rigidity. Rigidity can be ensured by making the frame member a closed cross section over the entire length in the vehicle width direction, but This will increase the weight.

[0006] In view of the above background, the problem that this invention aims to solve is to ensure both the rigidity and weight reduction of the bumper reinforcement that supports the first step portion and the second step portion provided on the rear bumper fascia. [Means for solving the problem]

[0007] In order to solve the above problems, the present invention provides a rear bumper fascia having a first step portion formed in the center of the vehicle width direction and a second step portion formed higher than the first step portion at a position shifted to one side of the first step portion in the vehicle width direction, and a bumper reinforcement arranged inside the rear bumper fascia, The bumper reinforcement is configured as a rear bumper structure that includes a frame member that has a bottom plate portion that extends between the bottom of the second step portion and the bottom of the first step portion, a front plate portion that extends upward from the front side of the bottom plate portion, and a rear plate portion that extends upward from the rear side of the bottom plate portion, and has an open cross section that opens upward over the entire length in the vehicle width direction between the front plate portion and the rear plate portion, a central bracket that is fixed to the front plate portion and the rear plate portion so as to cover the open cross section below the first step portion and supports the first step portion, and a support member that has leg plate portions fixed to the front plate portion and the rear plate portion so as to cover the open cross section at a position shifted to one side of the central bracket and supports the second step portion.

[0008] In the above configuration, it is preferable that the support member includes a first leg plate portion that supports the end of the second step portion on the first step portion side, and a second leg plate portion that is located to one side of the first leg plate portion and supports the second step portion from below.

[0009] It is more preferable that the first and second leg plate portions each have a lower end plate portion extending in the vehicle width direction and an ascending plate portion bent upward from the lower end plate portion, and that the front plate portion and the rear plate portion each have a first upper end portion welded to the first leg plate portion and a second upper end portion welded to the second leg plate portion at a position shifted to one side of the first upper end portion, and that at least one upper end portion of the first and second upper end portions is formed in a notch shape that contacts the lower end plate portion and ascending plate portion of the corresponding leg plate portion.

[0010] It is also preferable that the bumper reinforcement further includes a side bracket connected to one end of the frame member in the vehicle width direction, and that the connection portion of the frame member to the side bracket is present only on the bottom plate portion.

[0011] It is also preferable that the frame member has a fastening seat surface at the lower end of a bulge portion that partially pushes the bottom plate portion downward, and the rear bumper fascia has a lower end wall portion fastened to the fastening seat surface.

[0012] It is also preferable that the rear bumper fascia has the second step portion on both sides of the first step portion in the vehicle width direction, and the bumper reinforcement has the support member on both sides of the central bracket in the vehicle width direction. [Effects of the Invention]

[0013] By adopting the above-mentioned configuration, this invention can ensure both the rigidity and weight reduction of the bumper reinforcement that supports the first step portion and the second step portion provided on the rear bumper fascia. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a perspective view showing a rear bumper structure according to an embodiment of the present invention; [Figure 2] FIG. 2 is a perspective view showing the exterior of the rear bumper structure shown in FIG. 1. [Figure 3] FIG. 1 is a perspective view of a frame member according to an embodiment; [Figure 4] FIG. 4 is a plan view of the frame member of FIG. [Figure 5] A side view of the frame member of Figure 3 [Figure 6] FIG. 3 is a perspective view showing the vicinity of the lower end wall portion of the rear bumper fascia of FIG. [Figure 7] Enlarged view of the bracket on one side of Figure 1 [Figure 8] Cross section of line AA in Figure 7 [Figure 9]Cross section of line BB in Figure 7 [Figure 10] Cross section of line CC in Figure 7 [Figure 11] Cross section of line DD in Figure 7 [Figure 12] Cross section of line EE in Figure 7 [Figure 13] A perspective view of the side bracket and its surroundings in Figure 1 DETAILED DESCRIPTION OF THE INVENTION

[0015] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A rear bumper structure according to an embodiment of the present invention will now be described with reference to the accompanying drawings.

[0016] 1 and 2, the rear bumper structure according to the embodiment includes a rear bumper fascia 10 disposed at the rear end of a vehicle 1, and a bumper reinforcement 20 disposed inside the rear bumper fascia 10. Hereinafter, the concepts of front-rear direction, vehicle width direction, and up-down direction refer to the front-rear direction, vehicle width direction, and up-down direction of the vehicle 1.

[0017] The vehicle 1 in the illustrated example has rear doors 2 and 3 in the center in the vehicle width direction, and tail lamps 4 and 5 on both sides of the rear doors 2 and 3 in the vehicle width direction.

[0018] The overall structure of each of the rear bumper fascia 10 and the bumper reinforcement 20 is plane-symmetrical with respect to an imaginary plane extending in the longitudinal and vertical directions and passing through the center of the overall length of each of the rear bumper fascia 10 and the bumper reinforcement 20 in the vehicle width direction.

[0019] The rear bumper fascia 10 is open toward the front and has a shape that covers the bumper reinforcement 20 from behind, above, and both sides in the vehicle width direction. The entire rear bumper fascia 10 is made of a resin part that is integrally formed from synthetic resin. However, it is also possible to change the rear bumper fascia to one made of sheet metal.

[0020] The rear bumper fascia 10 has a first step portion 11 formed in the center of the rear bumper fascia 10 in the vehicle width direction, a second step portion 12 on one side formed higher than the first step portion 11 at a position closer to one side in the vehicle width direction with respect to the first step portion 11 (hereinafter, this one side will be simply referred to as "one side"), a third step portion 13 on one side formed higher than the second step portion 12 on one side at a position closer to one side with respect to the second step portion 12 on one side, a second step portion 14 on the other side formed higher than the first step portion 11 at a position closer to the opposite side in the vehicle width direction with respect to the first step portion 11 (hereinafter, this one side will be simply referred to as "the other side"), and a third step portion 15 on the other side formed higher than the second step portion 14 on the other side at a position closer to the other side with respect to the second step portion 14 on the other side.

[0021] Anti-slip pads 16, 17, and 18 are fixed to the upper surfaces of the first step portion 11 and the second step portions 12 and 14, respectively.

[0022] 1 includes a frame member 21 extending between the lower portion of the second step portion 12 on one side and the lower portion of the second step portion 14 on the other side, a central bracket 22 fixed to the center of the frame member 21 in the vehicle width direction, a one-side support member 23 fixed to one side of the frame member 21, an other-side support member 24 fixed to the other side of the frame member 21, a first side bracket 25 connected to one end of the frame member 21 in the vehicle width direction, a second side bracket 26 fixed to the other end of the frame member 21 in the vehicle width direction, and an attachment bracket 27 connected to the central bracket 22. Note that in each of the brackets 22 to 27, holes, recesses, etc. used for connection to other members or for attaching other members are omitted from the illustration as appropriate.

[0023] As shown in Figures 3 to 5, the frame member 21 integrally comprises a bottom plate portion 21a, a front plate portion 21b extending upward from the front side of the bottom plate portion 21a, and a rear plate portion 21c extending upward from the rear side of the bottom plate portion 21a. The bottom plate portion 21a, the front plate portion 21b, and the rear plate portion 21c form an open cross section that opens upward over the entire length of the bottom plate portion 21a in the vehicle width direction. The frame member 21 is made of a single metal plate. The overall shape of the frame member 21 is formed by press molding.

[0024] 3 to 6, the bottom plate portion 21a has a bulge portion 21d that is formed by pushing a portion of the bottom plate portion 21a downward in the vehicle width direction. Since the frame member 21 is press-molded into a shape having an open cross section that opens above the bottom plate portion 21a, the bulge portion 21d can be punched out during the above-mentioned press molding.

[0025] A through hole 21e is formed in the bulging portion 21d. A flat fastening seat surface 21f is formed around the through hole 21e at the lower end of the bulging portion 21d. The bulging portions 21d are formed at multiple locations on the bottom plate portion 21a in the vehicle width direction.

[0026] As shown in FIG. 6, the rear bumper fascia 10 has a lower end wall portion 19 that overlaps with the fastening seat surface 21f. The lower end wall portion 19 is a protruding piece that extends partially forward from the front lower edge of the rear bumper fascia 10. A through hole 19a is formed in the lower end wall portion 19. A clip (not shown) for fixing the lower end wall portion 19 to the bulging portion 21d is inserted into the through hole 19a in the lower end wall portion 19 and the through hole 21e in the bulging portion 21d. This fixation fastens the lower end wall portion 19 to the fastening seat surface 21f. The portions of the lower surface of the frame member 21 other than the fastening seat surface 21f are in a position that does not contact the rear bumper fascia 10, but because the fastening seat surface 21f is formed at the lower end of the bulging portion 21 that is pushed downward, there is no difference in height between the fastening seat surface 21f and the lower end wall portion 19. Therefore, no gap is created between lower end wall portion 19 and fastening seat surface 21f when fastened, and there is no significant deflection of lower end wall portion 19. As a result, the area near lower end wall portion 19 is less likely to deflect when an external force is applied, improving the rigidity of the lower portion of rear bumper fascia 10 against external forces.

[0027] 1, the center bracket 22 is disposed below the first step portion 11. The entire center bracket 22 is made of a single metal plate.

[0028] The front side of center bracket 22 is welded to mounting bracket 27. Mounting bracket 27 is provided for attaching a license plate (number plate) and for securing and fixing the surface rigidity of rear bumper fascia 10 in this vicinity.

[0029] The center bracket 22 is welded to the front plate portion 21b and the rear plate portion 21c. The front plate portion 21b and the rear plate portion 21c have flat upper center portions 21g and 21h that are aligned along the vehicle width direction and the front-rear direction, respectively (see FIGS. 3 to 5), and these upper center portions 21g and 21h are welded to the center bracket 22. In FIGS. 7 to 10, the positions of the welds W1 to W4 are indicated by black dots. Compared to the weld W1 between the center bracket 22 and the front plate portion 21b, the welds W2 to W4 between the center bracket 22 and the rear plate portion 21c are intermittently arranged so that their positions in the vehicle width direction differ from each other.

[0030] The central bracket 22 is also fixed to the lower end of the first step portion 11 shown in Fig. 1. When a downward load from a person's legs (hereinafter, this load will be referred to as "stepping load") is applied to the first step portion 11, the central bracket 22 can support the first step portion 11 from below. At this time, the stepping load acts on the front plate portion 21b and the rear plate portion 21c via the central bracket 22, and even if the front plate portion 21b and the rear plate portion 21c try to tip in a direction separating from each other in the front-to-rear direction (hereinafter, this behavior will be referred to as "opening"), the resistance of the central bracket 22 fixed to the front plate portion 21b and the rear plate portion 21c prevents the opening.

[0031] One support member 23 has a first leg plate 23a and a second leg plate 23b fixed to the front plate 21b and the rear plate 21c, a top plate 23c spanning the upper parts of the first leg plate 23a and the second leg plate 23b, and an extension plate 23d fixed to one side of the top plate 23c. Each of the first leg plate 23a to the extension plate 23d is made of a single metal plate.

[0032] As shown in Figures 1 and 7, the first and second leg plate portions 23a, 23b each have a lower end plate portion 23e, 23f extending in the vehicle width direction and an ascending plate portion 23g, 23h bent upward from the lower end plate portion 23e, 23f. The lower end plate portion 23e of the first leg plate portion 23a and the lower end plate portion 23f of the second leg plate portion 23b (hereinafter referred to as the "first lower end plate portion 23e" and the "second lower end plate portion 23f") each have a shape that follows the vehicle width direction. The ascending plate portion 23g of the first leg plate portion 23a and the ascending plate portion 23h of the second leg plate portion 23b (hereinafter referred to as the "first ascending plate portion 23g" and the "second ascending plate portion 23h") are bent in an arc shape at corners that connect to the corresponding first lower end plate portion 23e or second lower end plate portion 23f.

[0033] The first lower end plate portion 23e and the first upper end plate portion 23g are welded to the front plate portion 21b and the rear plate portion 21c at positions closer to one side of the center bracket 22. The positions of the welds W5 and W6 are indicated by black dots in Figures 7 and 11. The first lower end plate portion 23e is welded to a first upper end portion 21i formed on one side of the front plate portion 21b and a first upper end portion 21j formed on one side of the rear plate portion 21c. The closed cross section formed by the first lower end plate portion 23e and the frame member 21 is generally rectangular tubular, as shown in Figure 11.

[0034] As shown in FIGS. 3 and 7, the first upper end 21i of the front plate portion 21b and the first upper end 21j of the rear plate portion 21c are lower than the upper center portions 21g and 21h, respectively. The first upper end 21i of the front plate portion 21b is formed in a notch shape that contacts the front side of the first lower end plate portion 23e and the front side of the ascending plate portion 23g along an arc-shaped portion. The first upper end 21j of the rear plate portion 21c is formed in a notch shape that contacts the rear side of the first lower end plate portion 23e and the rear side of the ascending plate portion 23g along an arc-shaped portion. The adoption of such a notch shape makes it possible to weld not only the lower ends of the first lower end plate portion 23e and the second lower end plate portion 23f but also the side ends in the vehicle width direction of the first ascending plate portion 23g and the second ascending plate portion 23h to the front plate portion 21b and the rear plate portion 21c. For this reason, as shown in FIG. 7, the welded portions W5 and W6 are provided along the notched shape, which allows the welded portions W5 and W6 to have a long weld length.

[0035] The second lower end plate portion 23f is welded to the front plate portion 21b and the rear plate portion 21c at a position closer to one side than the first leg plate portion 23a. The positions of the welds W7 and W8 are indicated by black dots in FIGS. 7 and 12. The second lower end plate portion 23f is welded to a second upper end portion 21k formed on one side of the front plate portion 21b and a second upper end portion 21l formed on one side of the rear plate portion 21c. As shown in FIGS. 3 and 5, the second upper end portion 21k of the front plate portion 21b and the second upper end portion 21l of the rear plate portion 21c are each formed flat along the vehicle width direction and the front-rear direction. The closed cross section formed by the second lower end plate portion 23f and the frame member 21 is generally rectangular tubular, as shown in FIG. 12.

[0036] As shown in FIG. 1, the top plate portion 23c is disposed below the second step portion 12 on one side. As shown in FIGS. 1 and 13, the top plate portion 23c overlaps the upper portions of the first ascending plate portion 23g and the second ascending plate portion 23h and is welded to these upper portions. In FIG. 13, the positions of welds W9 to W10 on the rear side of the top plate portion 23c relative to the first ascending plate portion 23g and the second ascending plate portion 23h are indicated by black dots. Welds are also disposed in a similar manner on the front side of the top plate portion 23c. The top plate portion 23c is also fixed to the lower end of the second step portion 12 on one side shown in FIG. 1.

[0037] When a tread load is applied to one side of the second step portion 12, the support member 23 on one side can support the one side of the second step portion 12 from below. At this time, the first leg plate portion 23a supports the end portion on the other side (i.e., the first step portion 11 side) of the one side of the second step portion 12, and the second leg plate portion 23b supports the one side of the second step portion 12 from below. Even if the tread load acts on the front plate portion 21b and the rear plate portion 21c via the support member 23 on one side, the opening is prevented from opening due to the resistance of the first and second leg plate portions 23a, 23b fixed to the front plate portion 21b and the rear plate portion 21c.

[0038] 13, the rear end of the bumper arm 28 is disposed between the upper portion of the second leg plate portion 23b and one end of the frame member 21. The rear end of the bumper arm 28 is fixed to the second ascending plate portion 23h. The bumper arm 28 is used to connect a side member (not shown) of the vehicle body to the bumper reinforcement 20.

[0039] The extension plate portion 23d is disposed below the third step portion 13 on one side as shown in FIG. 1. As shown in FIGS. 1 and 13, the extension plate portion 23d has a shape that opens downward over the entire length of the extension plate portion 23d in the vehicle width direction. The other side of the extension plate portion 23d sandwiches one side of the top plate portion 23c in the front-rear direction and is welded to the top plate portion 23c at this sandwiching portion. One side of the extension plate portion 23d is welded to the first side bracket 25. In FIG. 13, the positions of welds W11 to W13 of the top plate portion 23c relative to the top plate portion 23c and the first side bracket 25 are indicated by black dots. When a pedestrian load is applied to the third step portion 13 on one side, the extension plate portion 23d can support the third step portion 13 on one side from below.

[0040] First side bracket 25 is connected to frame member 21 by welding. First side bracket 25 is provided to support extension plate portion 23d relative to frame member 21, to secure rear bumper fascia 10, to attach a side radar (not shown) for collision avoidance at the rear of the vehicle, and to ensure the rigidity of one side surface of plastic rear bumper fascia 10. If rear bumper fascia 10 is made of sheet metal, the side bracket can be omitted.

[0041] The connection portion of the frame member 21 to the first side bracket 25 is welded portion W14, the position of which is indicated by black ink in Figure 13. Welded portion W14 exists only on the underside of the bottom plate portion 21a. The entire portion of the frame member 21 on one side of the second lower end plate portion 23f remains as an open cross-section that is open upward. The reason why the connection portion of the first side bracket 25 and the frame member 21 is limited to the underside of the bottom plate portion 21a is to suppress vibration of the first side bracket 25 in the vehicle width direction.

[0042] The support member 24 on the other side shown in FIG. 1 has a structure that has the above-mentioned plane symmetry with respect to the support member 23 on one side, so only an outline will be given.

[0043] The other support member 24 has first and second leg plate portions 24a, 24b fixed to the front plate portion 21b and the rear plate portion 21c at a position closer to the other side of the central bracket 22, and is able to support the other side of the second step portion 14. These first and second leg plate portions 24a, 24b each have lower end plate portions 24c, 24d extending in the vehicle width direction, and ascending plate portions 24e, 24f bent upward from the lower end plate portions 24c, 24d.

[0044] The front plate portion 21b and the rear plate portion 21c each have a first upper end portion 21m, 21n welded to the first leg plate portion 24a and a second upper end portion 21o, 21p welded to the second leg plate portion 24b at a position closer to the other side of the first upper end portions 21m, 21n. The first upper end portion 21m formed on the other side of the front plate portion 21b and the first upper end portion 21n formed on the other side of the rear plate portion 21c are each formed in a notch shape that contacts the lower end plate portion 24c and the ascending plate portion 24e of the first leg plate portion 24a (see FIG. 3).

[0045] When a tread load is applied to the other-side second step portion 14, the other-side support member 24 can support the other-side second step portion 14 from below. At this time, the other-side first leg plate portion 24a supports the end portion of one side (i.e., the first step portion 11 side) of the other-side second step portion 14, and the second leg plate portion 23b supports the other-side second step portion 14 from below. Even if the tread load acts on the front plate portion 21b and the rear plate portion 21c via the other-side support member 24, the resistance of the first and second leg plate portions 24a, 24b fixed to the front plate portion 21b and the rear plate portion 21c prevents the opening from occurring.

[0046] Further, the second side bracket 26 shown in FIG. 1 has a structure that is plane symmetrical with respect to the first side bracket 25 as described above, and therefore a description thereof will be omitted.

[0047] As described above, this rear bumper structure comprises a rear bumper fascia 10 having a first step portion 11 formed in the center of the vehicle width direction, second step portions 12, 14 formed higher than the first step portion 11 at a position closer to one side (one side or the other) of the first step portion 11 in the vehicle width direction, and a bumper reinforcement 20 arranged inside the rear bumper fascia 10.

[0048] The bumper reinforcement 20 includes a frame member 21 that integrally includes a bottom plate portion 21a extending between the lower portions of the second step portions 12, 14 and the lower portion of the first step portion 11, a front plate portion 21b extending upward from the front side of the bottom plate portion 21a, and a rear plate portion 21c extending upward from the rear side of the bottom plate portion 21a, and that has an open cross section that is open upward between the front plate portion 21b and the rear plate portion 21c over the entire length in the vehicle width direction. This makes the frame member 21 lighter than a frame with a closed cross section over the entire length, and since the pedestrian load acts on the front plate portion 21b and the rear plate portion 21c that face upward, the front plate portion 21b and the rear plate portion 21c are less likely to bend under the action of the pedestrian load compared to when the open opening of the frame member 21 faces in the fore-and-aft direction, which is effective in improving the rigidity of the bumper reinforcement 20 against the pedestrian load. Furthermore, the bumper reinforcement 20 is provided with a central bracket 22 that is fixed to the front plate portion 21b and the rear plate portion 21c so as to cover the open cross section below the first step portion 11 and supports the first step portion 11, and support members 23, 24 that have first and second leg plate portions 23a, 23b, 24a, 24b fixed to the front plate portion 21b and the rear plate portion 21c at a position closer to one side (one side or the other) of the central bracket 22 and cover the open cross section, and support members 23, 24 that support the second step portions 12, 14. Therefore, by utilizing the rigid central bracket 22 and support members 23, 24 for supporting the first step portion 11 and second step portions 12, 14 on which the tread load acts, the open cross-section frame member 21 is made into a closed cross-section at key points where the tread load acts, and the frame member 21 can be prevented from opening over a wide range in the vehicle width direction, thereby ensuring sufficient rigidity of the bumper reinforcement 20 against the tread load while avoiding an increase in the weight of the bumper reinforcement 20. Therefore, this rear bumper structure can achieve both ensuring rigidity and weight reduction of the bumper reinforcement 20 that supports the first step portion 11 of the first stage and the second step portions 12, 14 of the second stage provided on the rear bumper fascia 10.

[0049] Further, the support members 23, 24 include first leg plate portions 23a, 24a that support the ends of the second step portions 12, 14 on the first step portion 11 side, and second leg plate portions 23b, 24b that are located on the one side (one side or the other side) of the first leg plate portions 23a, 24a and support the second step portions 12, 14 from below. This makes it possible to support the second step portions 12, 14 widely in the vehicle width direction, and to use the first and second leg plate portions 23a, 24a, 23b, 24b for this purpose to widely reinforce the one side (one side or the other side) of the frame member 21 in the vehicle width direction, thereby preventing the frame member 21 from opening open on the one side (one side or the other side).

[0050] The first and second leg plate portions 23a, 23b, 24a, 24b each have lower end plate portions 23e, 23f, 24c, 24d extending in the vehicle width direction, and upper plate portions 23g, 23h, 24e, 24f bent upward from the lower end plate portions 23e, 23f, 24c, 24d, and the front plate portion 21b and the rear plate portion 21c each have first upper end portions 21i, 21j, 21m, 21n welded to the first leg plate portion 23a. and second upper ends 21k, 21l, 21o, 21p welded to the second leg plate 23b at a position closer to the first upper ends 21i, 21j. At least one of the first and second upper ends 21i, 21j, 21m, 21n is formed with a notch that contacts the lower end plate 23e, 24c and the ascending plate 23g, 24e of the corresponding leg plate 23a, 24a. This allows for a longer weld length. The longer the overall weld length of the center bracket 22 and the support members 23, 24 to the front plate 21b and the rear plate 21c, the more effective it is in preventing gaping. Therefore, this rear bumper structure can increase the welding length between the leg plate portions 23a, 24a and the front plate portion 21b and rear plate portion 21c by using the aforementioned notch shape, making it easier to ensure the rigidity of the bumper reinforcement 20 against pedestrian loads.

[0051] In this embodiment, sufficient rigidity can be ensured simply by increasing the welding length of the first leg plate portions 23a, 24a, so the welding length of the second leg plate portions 23b, 24b is not increased, but if further improvement in rigidity is desired, the welding length of the second leg plate portions 23b, 24b can also be increased.

[0052] The bumper reinforcement 20 further includes side brackets 25, 26 connected to one end of the frame member 21 in the vehicle width direction, and the welded portion W14, which serves as the connection portion of the frame member 21 to the side brackets 25, 26, is present only on the bottom plate portion 21a. This makes it possible to suppress vibration of the side brackets 25, 26 in the vehicle width direction.

[0053] Furthermore, frame member 21 has fastening seat surface 21f at the lower end of bulging portion 21d, which is formed by partially pushing bottom plate portion 21a downward, and rear bumper fascia 10 has lower end wall portion 19 fastened to fastening seat surface 21f. This reduces the difference in height between fastening seat surface 21f and lower end wall portion 19 from the bottom plate portion 21a side, preventing a gap from occurring between lower end wall portion 19 and fastening seat surface 21f when fastened, and ultimately makes the area near lower end wall portion 19 less likely to bend when an external force is applied, improving the rigidity of the lower portion of rear bumper fascia 10 against external forces.

[0054] Additionally, the rear bumper fascia 10 has second step portions 12, 14 on both sides (one side and the other side) in the vehicle width direction relative to the first step portion 11, and the bumper reinforcement 20 has support members 23, 24 on both sides (one side and the other side) in the vehicle width direction relative to the central bracket 22. This allows the structures of the rear bumper fascia 10 and the bumper reinforcement 20 to be balanced on both sides in the vehicle width direction, while ensuring the rigidity and reducing the weight of the bumper reinforcement 20 that supports both second step portions 12, 14.

[0055] In this embodiment, the support members 23, 24 are constructed on the frame member 21 using multiple brackets, including brackets with first leg plate portions 23a, 24a and brackets with second leg plate portions 23b, 24b. However, the structure of the support members is not particularly limited in the present invention, and the frame member may be formed into a closed cross-section using components arranged on the frame member as components of the support members. For example, depending on the widthwise length of the second step portion, it is possible to omit the second leg plate portion, or to add a leg plate portion different from the first and second leg plate portions and use it to form a closed cross-section of the frame member. It is also possible to employ a bracket integrally including the first and second leg plate portions. In addition, in this embodiment, the second step portions 12, 14 are provided on both widthwise sides of the vehicle 1, and the support members 23, 24 are provided corresponding to these second step portions. However, the scope of the present invention also includes an embodiment in which the second step portion and the support member are provided on only one widthwise side of the vehicle.

[0056] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. Therefore, the scope of the present invention is defined by the claims rather than the above description, and it is intended to include all modifications within the meaning and scope of the claims.

[0057] Although various embodiments have been described above, it goes without saying that the present invention is not limited to such examples. It is clear that a person skilled in the art can conceive of various modifications or alterations within the scope of the claims, and it is understood that these also naturally fall within the technical scope of the present invention. Furthermore, the components of the above embodiments may be combined in any manner as long as they do not deviate from the spirit of the invention.

[0058] This application is based on a Japanese patent application (Patent Application No. 2022-058045) filed on March 31, 2022, the contents of which are incorporated herein by reference. [Explanation of symbols]

[0059] 10 Rear bumper fascia 11 First Step 12,14 Second step section 19 Lower end wall 20 Bumper Reinforcement 21 Frame members 21a Bottom plate part 21b Front plate part 21c Rear plate part 21d bulge 21f Fastening seat 21i, 21j, 21m, 21n First upper end 21k, 21l, 21o, 21p Second upper end 22 Center bracket 23,24 Support member 23a,24a First leg plate part 23b,24b Second leg plate part 23e, 23f, 24c, 24d Lower end plate part 23g,23h,24e,24f Ascending plate part 25,26 Side bracket W14 Welded section (connection)

Claims

1. a rear bumper fascia having a first step portion formed in a center portion in a vehicle width direction and a second step portion formed higher than the first step portion at a position shifted to one side in the vehicle width direction with respect to the first step portion; a bumper reinforcement disposed inside the rear bumper fascia, The bumper reinforcement a frame member having an open cross section that is open upward over the entire length in the vehicle width direction between the front plate portion and the rear plate portion, the frame member integrally including a bottom plate portion extending between the lower part of the second step portion and the lower part of the first step portion, a front plate portion extending upward from the front side of the bottom plate portion, and a rear plate portion extending upward from the rear side of the bottom plate portion; a central bracket fixed to the front plate portion and the rear plate portion so as to cover the open cross section below the first step portion and support the first step portion; a support member that supports the second step portion and has a leg plate portion fixed to the front plate portion and the rear plate portion so as to cover the open cross section at a position shifted to one side of the central bracket.

2. The support member is A first leg plate portion supporting an end portion of the second step portion on the first step portion side; a second leg plate portion located on the one side of the first leg plate portion and supporting the second step portion from below; The rear bumper structure according to claim 1 , comprising:

3. The first and second leg plate portions each have a lower end plate portion extending in the vehicle width direction and an ascending plate portion bent upward from the lower end plate portion, the front plate portion and the rear plate portion each have a first upper end portion welded to the first leg plate portion and a second upper end portion welded to the second leg plate portion at a position shifted to the one side relative to the first upper end portion, 3. The rear bumper structure according to claim 2, wherein at least one of the first and second upper end portions is formed as a notch that contacts the lower end plate portion and the upper plate portion of the corresponding leg plate portion.

4. The bumper reinforcement further includes a side bracket connected to one end of the frame member in the vehicle width direction, 3. The rear bumper structure according to claim 1, wherein the connection portion of the frame member to the side bracket is present only at the bottom plate portion.

5. 3. The rear bumper structure according to claim 1, wherein the frame member has a fastening seat surface at the lower end of a bulge portion formed by partially pushing the bottom plate portion downward, and the rear bumper fascia has a lower end wall portion fastened to the fastening seat surface.

6. the rear bumper fascia has the second step portions on both sides of the first step portion in the vehicle width direction, 3. The rear bumper structure according to claim 1, wherein the bumper reinforcement has the support members on both sides of the central bracket in the vehicle width direction.

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