JP3734520B2 - Car rear bumper mounting structure - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to an automobile rear bumper mounting structure.
[0002]
[Prior art]
As a conventional rear bumper mounting structure for an automobile, for example, the structure shown in FIGS. 4 and 5 is known (refer to Japanese Utility Model Publication No. 64-48373 as a similar technique).
[0003]
Reference numeral 1 denotes a rear side member, which is disposed on both the left and right sides of the rear part of the vehicle body. The rear side member 1 has an inverted hat shape in cross section, and left and right rear end flanges 2 and a downward flange 3 are formed at the rear end thereof. Further, the rear side member 1 is provided with a bracket 4 provided between left and right side portions, and a pair of front and rear mounting holes 4a is formed in the bracket 4.
[0004]
A rear floor panel 5 is connected on the rear side member 1, and a working hole 5a corresponding to the mounting hole 4a is formed in the rear floor panel 5. The working hole 5 a is closed with a cap 6.
[0005]
A rear panel 7 is connected to the rear end flange 2 and the downward flange 3 of the rear side member 1. An opening 7 a is formed at a position corresponding to the bracket 4 of the rear panel 7.
[0006]
A rear bumper 8 is composed of a bumper reinforcement 9, a bumper fascia 10, and a stay 11. Stay 11 intended to be connected from the lower surface to the upper portion 9a of the bumper reinforcement 9, Kino mounting hole 11a with weld nuts corresponding to the mounting hole 4a of the bracket 4 is provided at its front end.
[0007]
Therefore, as a conventional method of attaching the rear bumper 8, the stay 11 is inserted into the rear side member 1 from the opening 7a, the stay 11 is overlapped under the bracket 4, and the mounting holes 4a and 11a of both are matched. The mounting holes 4a and 11a are fastened with bolts 12 inserted from the work holes 5a of the rear floor panel 5. By attaching the stay 11 to the bracket 4, the rear bumper 8 is attached to the rear side member 1. When the attachment work of the stay 11 is completed, the work hole 5a of the rear floor panel 5 is closed with a cap 6 and the opening 7a of the rear panel 7 is also closed with a filler (not shown) for waterproofing.
[0008]
[Problems to be solved by the invention]
However, in such a conventional technique, the load F when the automobile is subjected to a rear collision is transmitted from the bumper reinforcement 9 to the bracket 4 portion of the rear side member 1 only via the stay 11. When the load F is large, the load F may not be received. Therefore, as a countermeasure therefor, the bracket 4 thickness sufficiently increased, since the bracket 4 should Ru specially strongly connected to the inner surface of the rear side member 1, mounting work of the bracket 7 of the total assembly work It causes the efficiency to decrease.
[0009]
In addition, mounting the rear bumper 8 only with the stay 11 is disadvantageous in terms of mounting rigidity of the rear bumper 8, and there is a possibility that the rear bumper 8 may rattle due to vibration or the like when the vehicle is running. Therefore, as a countermeasure, it is necessary to add a rattling-preventing member to the rear bumper 8, which increases the number of parts and the number of work steps.
[0010]
Further, although the rear bumper 8 itself is mounted from the outside of the vehicle, the mounting work with the bolts 12 is performed from the work hole 5a of the rear floor panel 5 in the vehicle interior, so that the mounting work of the rear bumper 8 is very troublesome. .
[0011]
In addition, in order to ensure waterproofness to the rear side member 1 side, it is necessary to close the working hole 5a with the cap 6 and the opening 7a of the rear panel 7 with the filler. In addition, the work man-hours will increase.
[0012]
As a conventional structure, a “rear cross member” having a closed cross-sectional structure may be used instead of the plate-like rear panel 7, but the existence of the above-described problems does not change.
[0013]
The present invention has been made by paying attention to such a conventional technique, and can reliably receive a load, improve mounting rigidity and mounting workability, and ensure waterproofness without increasing parts and man-hours. It is an object of the present invention to provide a rear bumper mounting structure for an automobile that can obtain the above.
[0014]
[Means for Solving the Problems]
According to the first aspect of the present invention, the front end portion of the rear cross member having a closed cross-section structure is connected to the rear end flanges formed on the left and right sides of the rear end of the rear side member, and the rear end of the front portion of the rear cross member end portion is Each connecting part of the flange and each corresponding part in the rear surface part are connected by a pair of left and right braces, and a mounting hole is formed in the connecting part at the rear end of each brace in the rear surface part of the rear cross member, and the bumper reinforcement A mounting hole that matches the mounting hole on the rear surface of the rear cross member is formed in the bent flange on the left and right sides of the stay mounted on the stay, and the bumper reinforcement is connected to each brace in the rear cross member through the mounting holes. The rear side member, the brace, and the stay are attached to the rear end of the vehicle by connecting means, and are substantially straight along the longitudinal direction of the vehicle body. Placed at the rear position of the rear cross member of the mounting hole in the bumper reinforcement is obtained by forming a working opening for the coupling means.
[0015]
According to the second aspect of the present invention, flanges are respectively formed at the upper end and the lower end of the brace, and the flanges are respectively connected to the upper surface portion and the lower surface portion of the rear cross member.
[0016]
According to a third aspect of the invention, the outer portion of the upper surface portion of the rear cross member is curved upward, and the upper portion of the outer brace is bent inward so as to be substantially perpendicular to the curved upper surface portion. It is connected to the.
[0018]
[Action]
According to the first aspect of the present invention, since the load applied to the rear bumper is linearly transmitted from the bumper reinforcement and the stay → the brace → the rear side member, an excessive load can be received by the entire rear side member.
[0019]
In addition, the rear cross member has a closed cross section formed by the front and rear surfaces of the rear cross member and left and right braces, and the bumper reinforcement is attached to the rear side member via the closed cross section. improves.
[0020]
Furthermore, since the rear bumper can be mounted from the outside of the vehicle, the mounting workability is better than the case where the rear bumper is mounted from the inside of the vehicle as in the prior art.
[0021]
In addition, it is not necessary to provide a work opening or the like at a position where there is a problem with waterproofing for mounting the rear bumper, and a mounting hole formed on the rear surface portion of the rear cross member is inevitably formed by the coupling means. Since it is blocked, the number of parts and the number of work steps are not increased for waterproofness.
[0022]
According to the second aspect of the present invention, since the upper and lower flanges of the brace are connected to the upper surface portion and the lower surface portion of the rear cross member, the mounting rigidity of the rear bumper is further increased.
[0023]
According to the third aspect of the present invention, the upper portion of the outer brace is bent inward, and the upper portion is connected to the curved upper surface portion of the rear cross member at a substantially right angle. When an inward-facing flange is formed at the upper end of the flange, the angle between the flange and the upper portion of the brace is substantially perpendicular, making it easy to connect the flange to the upper surface of the rear cross member. That is, when the angle is an acute angle, it is difficult to perform connection work by spot welding or the like, but when it is substantially right angle, the work becomes easy.
[0024]
According to the invention described in claim 4, since the working opening for the coupling means is formed at the rear position of the mounting hole of the rear cross member in the bumper reinforcement, the mounting direction of the rear bumper coincides with the working direction of the coupling means. The mounting workability is improved.
[0025]
【Example】
A preferred embodiment of the present invention will be described below with reference to FIGS. In addition, the description which overlaps with the former is abbreviate | omitted.
[0026]
A rear side member 13 has left and right rear end flanges 13a and a downward flange 13b. A rear floor panel 14 is connected on the rear side member 13. This rear floor panel 14 is not formed with any “work holes”.
[0027]
A rear cross member 15 includes a rear cross member main body 16 having a U-shaped cross section and a closing plate 17. A flange 18 a that is lowered by one step is formed at the rear end of the upper surface portion 18 of the rear cross member main body 16, and a downward flange 19 a is formed at the rear end of the lower surface portion 19. A rearward flange 17a is formed at the upper end of the closing plate 17, and the flange 17a is connected to the flange 18a of the rear cross member main body 16. The lower end of the closing plate 17 is a downward flange of the rear cross member main body 16. 19a is connected.
[0028]
By connecting the closing plate 17 to the rear cross member main body 16, the rear cross member 15 has a closed cross-sectional structure. Accordingly, the front surface portion 20, the upper surface portion 18, and the lower surface portion 19 of the rear cross member main body 16 are the “front surface portion”, “upper surface portion”, and “lower surface portion” of the rear cross member 15, respectively, and the closing plate 17 is the “rear surface portion”. It becomes. The outer portion of the upper surface 18 of the rear cross member 15 is curved upward, and the closing plate 17 has a corresponding shape.
[0029]
A pair of left and right braces 21 and 22 are provided in the end portion of the rear cross member 15. These braces 21 and 22 respectively have flanges 21a, 21b, 21c, 21d, 22a, 22b, 22c, and 22d that are inward (rightward in FIG. 1) in the front-rear and up-down directions. 17, connected to the upper surface portion 18 and the lower surface portion 19. The upper portion 21e of the outer brace 21 is bent inward at an angle θ so that the upper portion 21e and the flange 21c connected to the upper surface portion 18 are at right angles. That is, if the outer brace 21 is connected straight to the upper surface portion 18, the formation angle of the flange 21c becomes an acute angle, and spot welding between the flange 21c and the upper surface portion 18 becomes difficult. The outer brace 21 is bent as described above. Since the inner brace 22 is connected to the horizontal portion of the upper surface portion 18, it is not necessary to have such a bent shape.
[0030]
A pair of upper and lower welding bolts 23 as "joining means" are attached to the rear flanges 21b and 22b of the braces 21 and 22 from the front side with the threaded portions facing the rear side. And the attachment hole 24 for making the thread part of the welding bolt 23 protrude in the position corresponding to each welding bolt 23 of the closing plate 17 is formed.
[0031]
With the braces 21 and 22 having the above-described structure, the front surface portion 20 of the rear cross member 15 and the closing plate 17 as the “rear surface portion” are connected in the front-rear direction, so that the overall rigidity of the rear cross member 15 is increased. Has been increased. The front portion 20 of the rear cross member 15 is connected to the rear end flange 13a and the downward flange 13b of the rear side member 13. The connecting portion of the rear cross member 15 to the front portion 20 is shown in FIG. As shown, the rear side member 13 matches the connection portion of each rear end flange 13a.
[0032]
Reference numeral 25 denotes a stay, which has a rear-facing hat shape having front end flanges 26 on the left and right sides, and flanges 27 that are bent from both the left and right sides. Further, the front end flange 26 is formed with upper and lower mounting holes 26 a corresponding to the mounting holes 24 of the closing plate 17. The upper and lower flanges 278 of the stay 25 and the upper surface portion 29 a and the lower surface portion 29 b of the bumper reinforcement 29 of the rear bumper 28 are spot welded at each spot point S, and the stay 25 is integrated with the bumper reinforcement 29. Further, by welding the stay 25 to the bumper reinforcement 29, the front end surface 25a of the stay 25 is brought into contact with the rear surface portion 29c of the bumper reinforcement 29. Further, work openings 30 are formed on both the left and right sides of the portion of the rear surface portion 29c of the bumper reinforcement 29 where the front end surface 25a is abutted. Reference numeral 31 denotes a bumper fascia.
[0033]
Therefore, as a method of attaching the rear bumper 28, the front end flange 26 of the stay 25 integrated with the bumper reinforcement 29 is set on the closing plate 17 of the rear cross member 15 and protrudes from the attaching hole 24 of the closing plate 17. The threaded portion of the welding bolt 23 is passed through the mounting hole 26a of the front end flange 26 of the stay 25, and a nut 32 as a “joining means” inserted from the work opening 30 of the bumper reinforcement 29 is fastened to the welding bolt 23. The force 29 is attached to the rear cross member 15. After the bumper reinforcement 29 is attached, a bumper fascia 31 is attached to the bumper reinforcement 29, and the bumper reinforcement 29 is covered with the bumper fascia 31.
[0034]
Since this embodiment has the above structure, it has the following advantages.
[0035]
Installation workability [0036]
Furthermore, since the mounting direction of the nut 32 and the mounting direction of the rear bumper 28 coincide with each other and the mounting operation with the nut 32 can be performed on the outside of the vehicle, the operation is performed on the inside of the vehicle as in the conventional case. Good installation workability. Also, when the bumper reinforcement 29 is exchanged, the bumper fascia 31 is removed from the rear bumper 28 and the nut 32 can be easily removed from the work opening 30.
[0037]
Load transmission [0038]
The load F applied to the rear bumper 28 due to the rear collision of the automobile is linearly transmitted from the bumper reinforcement 29 → the stay 25 → the braces 21 and 22 → the rear side member 13, so that the excessive load F is also received by the entire rear side member 13. be able to. Therefore, a sufficient reaction force against the load F can be generated, and deformation of the vehicle body can be suppressed. In particular, in this embodiment, the front end surface 25a of the stay 25 is in a state of abutting against the rear surface portion 29c of the bumper reinforcement 29, so that the burden on the welding spot point S can be reduced.
[0039]
Mounting rigidity 【0040】
As shown in FIG. 3, a closed cross section H is formed in the rear cross member 15 by a front surface portion 20 of the rear cross member 15, a closing plate 17 as a “rear surface portion”, and left and right braces 21, 22. Since the stay 25 of the rear bumper 28 is attached to the rear side member 13 via the portion H, the attachment rigidity of the rear bumper 28 is improved. Therefore, it is possible to prevent the rear bumper 28 from rattling due to vibration during traveling, and the resistance to lateral and vertical loads applied to the bumper reinforcement 29 is increased.
[0041]
Waterproof [0042]
For mounting the rear bumper 28, it is not necessary to form a working opening at a position that is a problem in terms of waterproofing, and the mounting hole 24 formed in the closing plate 17 is inevitably attached by the welding bolt 23 and the nut 32. Therefore, it is possible to reliably prevent water from entering the rear cross member 15. Therefore, it is not necessary to use a cap or a filler for waterproofness, and the number of parts and work man-hours can be reduced.
[0043]
In the above embodiment, the working opening 30 is formed in the bumper reinforcement 29. However, the working opening 30 is not necessarily formed, and depending on the shape of the bumper reinforcement 29, the bumper reinforcement 29 may be The attachment work by the bolt / nut means can be performed from the gap with the rear cross member 15.
[0044]
【The invention's effect】
According to the first aspect of the present invention, since the load applied to the rear bumper is linearly transmitted from the bumper reinforcement and the stay → the brace → the rear side member, an excessive load can be received by the entire rear side member.
[0045]
In addition, the rear cross member has a closed cross section formed by the front and rear surfaces of the rear cross member and left and right braces, and the bumper reinforcement is attached to the rear side member via the closed cross section. improves.
[0046]
Furthermore, since the rear bumper can be mounted from the outside of the vehicle, the mounting workability is better than the case where the rear bumper is mounted inside the vehicle as in the prior art.
[0047]
In addition, it is not necessary to provide a work opening or the like at a position where there is a problem with waterproofing for mounting the rear bumper, and a mounting hole formed on the rear surface portion of the rear cross member is inevitably formed by the coupling means. Since it is blocked, the number of parts and the number of work steps are not increased for waterproofness. In addition, since the working opening for the coupling means is formed at the rear position of the mounting hole of the rear cross member in the bumper reinforcement, the mounting direction of the rear bumper and the working direction of the coupling means coincide with each other, and the mounting workability of the rear bumper is improved. .
[0048]
According to the second aspect of the present invention, since the upper and lower flanges of the brace are connected to the upper surface portion and the lower surface portion of the rear cross member, the mounting rigidity of the rear bumper is further increased.
[0049]
According to the third aspect of the present invention, the upper portion of the outer brace is bent inward, and the upper portion is connected to the curved upper surface portion of the rear cross member at a substantially right angle. When an inward-facing flange is formed at the upper end of the flange, the angle between the flange and the upper portion of the brace is substantially perpendicular, making it easy to connect the flange to the upper surface of the rear cross member. That is, when the angle is an acute angle, it is difficult to perform connection work by spot welding or the like, but when it is substantially right angle, the work becomes easy.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view showing a rear bumper mounting structure for an automobile according to an embodiment of the present invention.
FIG. 2 is a longitudinal cross-sectional view showing a brace attached state in a rear cross member.
3 is a cross-sectional view taken along the line SA-SA in FIG.
4 is an exploded perspective view showing a rear bumper mounting structure of a DA portion in FIG. 5 in a conventional automobile.
FIG. 5 is a perspective view of an automobile showing a conventional example.
[Explanation of symbols]
13 Rear side member 13a Rear end flange 15 Rear cross member 17 Closing plate (rear part)
20 Front part 21, 22 Brace 23 Welding bolt (coupling means)
24 Mounting hole 29 Bumper reinforcement 32 Nut (coupling means)

Claims (3)

Connect the front part of the closed cross-section rear cross member to the rear end flanges formed on the left and right sides of the rear end of the rear side member,
Connecting each connection part of the rear end flange in the front part of the rear cross member end part and each corresponding part in the rear face part with a pair of left and right braces,
A mounting hole is formed in the connection part of the rear end of each brace on the rear surface of the rear cross member, and the mounting holes on the left and right sides of the stay mounted on the bumper reinforcement are aligned with the mounting holes on the rear surface of the rear cross member. A mounting hole is formed, and a bumper reinforcement is attached to the rear end of each brace in the rear cross member via each mounting hole by a coupling means, and the rear side member, the brace, and the stay are connected to the vehicle body. and arranged substantially linearly along the longitudinal direction of,
A rear bumper mounting structure for an automobile, wherein a work opening for a coupling means is formed at a rear position of a mounting hole of a rear cross member in the bumper reinforcement. 2. A rear bumper mounting structure for an automobile according to claim 1, wherein flanges are respectively formed at the upper end and the lower end of the brace, and the flanges are respectively connected to the upper surface portion and the lower surface portion of the rear cross member. The outer portion of the upper surface portion of the rear cross member is bent upward, and the upper portion of the outer brace is bent inward and connected at a substantially right angle to the curved upper surface portion. The rear bumper mounting structure of the described automobile.

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