JPH08175430A - Rear bumper fitting structure for automobile - Google Patents

Abstract

PURPOSE: To provide a rear bumper fitting structure for an automobile, which can surely receive a load and which can improve the fitting rigidity and the fitting workability and which can obtain the reliable water resistance without increasing the number of part items and the man-hours. CONSTITUTION: The front surface 20 of a rear cross member 15 is connected to a rear end flange 13a of a rear side member 13, and the front surface 20 and the rear surface 17 of the rear cross member 15 are connected by braces 21, 22, and the rear surface 17 is formed with fitting holes 24, and while a bumper reinforcement 29 is fitted to the rear end of each brace 21, 22 inside of the rear cross member 15 by connecting means 23, 32 through the fitting holes 24.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle rear bumper mounting structure.

[0002]

2. Description of the Related Art As a conventional vehicle rear bumper mounting structure, for example, those shown in FIGS. 4 and 5 are known (for a similar technique, see Japanese Utility Model Laid-Open No. 64-48373).

Reference numeral 1 denotes a rear side member, which is arranged on the left and right sides of the rear part of the vehicle body of the automobile. This rear side member 1
Has an inverted hat cross section, and left and right rear end flanges 2 and downward flanges 3 are formed at the rear ends thereof. Further, the rear side member 1 is provided with a bracket 4 which is installed between the left and right side surfaces, and the bracket 4 is formed with a pair of front and rear mounting holes 4a.

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 5a is closed by a cap 6.

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 7a is formed at a position of the rear panel 7 corresponding to the bracket 4.

The rear bumper 8 is composed of a bumper reinforcement 9, a bumper fascia 10, and a stay 11. Stay 11 is bumper reinforcement 9
Is connected to the upper surface portion 9a of the bracket from below, and a mounting hole 11a for thrusting a welding nut corresponding to the mounting hole 4a of the bracket 4 is provided at the front end thereof.

Therefore, as a conventional mounting method of the rear bumper 8, the stay 11 is opened from the opening 7a to the rear side member 1.
Inserting the stay 11 into the inside, stacking the stay 11 under the bracket 4, aligning the mounting holes 4a, 11a of the both, and using the bolt 12 inserted from the working hole 5a of the rear floor panel 5, the mounting holes 4a, 11a part Conclude This stay 1
1 to the bracket 4 allows the rear bumper 8
Is attached to the rear side member 1. When the work for attaching 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]

However, in such a conventional technique, the load F when the vehicle receives a rear-end collision is changed from the bumper reinforcement 9 to the stay 11.
Since it is transmitted to only the bracket 4 portion of the rear side member 1 via the, when the load F is large, the load F
You may not be able to accept it. Therefore, as a countermeasure for that, it is necessary to sufficiently increase the plate thickness of the bracket 4 and to connect the bracket 4 to the inner surface of the rear side member 1 with extra strength, so that the mounting work of the bracket 7 is efficient in the entire assembling work. Cause to decrease.

Further, the fact that the rear bumper 8 is mounted only by the stay 11 is disadvantageous in terms of mounting rigidity of the rear bumper 8, and there is a risk that the rear bumper 8 will rattle due to vibration or the like when the vehicle is running. Therefore, as a countermeasure against this, it is necessary to add a member for preventing rattling to the rear bumper 8, resulting in an increase in the number of parts and the number of working steps.

Further, although the rear bumper 8 itself is mounted from the outside of the vehicle, the mounting work of the rear bumper 8 with the bolt 12 is performed by the working hole 5 of the rear floor panel 5 in the vehicle interior.
Since it is performed from a, the mounting work of the rear bumper 8 is very troublesome.

In addition, in order to ensure the waterproofness of 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. However, this also leads to an increase in parts and man-hours.

As a conventional structure, a plate-shaped rear panel 7 is used.
In some cases, a "rear cross member" having a closed cross-section structure may be used instead of the above, but the existence of the above-mentioned problems remains.

The present invention has been made by paying attention to such a conventional technique, can reliably receive a load, improves the mounting rigidity and the mounting workability, and can increase the number of parts and man-hours without fail. Provided is a rear bumper mounting structure for an automobile, which can obtain excellent waterproofness.

[0014]

According to the first aspect of the present invention,
The front end of the rear cross member having a closed cross-section is connected to the rear end flanges formed on the left and right sides of the rear end of the rear side member. The corresponding portions on the surface portion are connected to each other by a pair of left and right braces, and mounting holes are formed at the connection portions at the rear ends of the braces on the rear surface portion of the rear cross member, and the bumper reinforcement is attached to the rear portion through the mounting holes. It is attached to the rear end of each brace in the cross member by a coupling means.

According to a second aspect of the present invention, flanges are formed at the upper and lower ends of the brace, and the flanges are connected to the upper surface and the lower surface of the rear cross member, respectively.

According to the third aspect of the present invention, the outer portion of the upper surface of the rear cross member is curved upward, and the upper portion of the outer brace is bent inward to the curved upper surface. Are connected at approximately right angles.

According to a fourth aspect of the present invention, at the rear position of the mounting hole of the rear cross member in the bumper reinforcement,
A working opening for the coupling means is formed.

[0018]

According to the first aspect of the present invention, the load applied to the rear bumper is linearly transmitted to the bumper reinforcement → the brace → the rear side member, so that the entire rear side member can receive an excessive load. .

Further, a closed cross-section portion is formed in the rear cross member by front and rear surface portions 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 portion. Mounting rigidity is improved.

Further, since the rear bumper mounting work can be performed from the outside of the vehicle, the workability of mounting is better than that in the conventional case where the rear bumper is mounted inside the vehicle.

In addition, for mounting the rear bumper,
It is not necessary to provide a work opening or the like at a position that poses a problem in terms of waterproofing, and the mounting hole formed in the rear surface of the rear cross member is inevitably blocked by the coupling means. The number of points and work man-hours will not increase.

According to the second aspect of the present invention, since the flanges at the upper end and the lower end of the brace are connected to the upper surface portion and the lower surface portion of the rear cross member respectively, the mounting rigidity of the rear bumper is further enhanced.

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 of the rear cross member at a substantially right angle. When the flange facing inward is formed at the upper end of the outer brace, the angle between the flange and the upper portion of the brace becomes substantially right angle, which facilitates connection work of the flange to the upper surface of the rear cross member. That is, when the angle is an acute angle, it becomes difficult to perform connection work by spot welding or the like, but when the angle is substantially right, the work becomes easy.

According to the fourth aspect of the present invention, 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 are uniform. The workability of mounting the rear bumper is improved.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to FIGS.
It will be described based on. It should be noted that the description overlapping with the conventional one is omitted.

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. No "working hole" or the like is formed in the rear floor panel 14.

Reference numeral 15 denotes a rear cross member, which is a rear cross member body 16 having a U-shaped cross section and a closing plate 17.
And consists of. On the rear end of the upper surface 18 of the rear cross member body 16, there is formed a flange 18a that is lowered by one step, and on the rear end of the lower surface 19, a downward flange 19a is formed. A rearward facing flange 17a is formed on the upper end of the closing plate 17, and the flange 17a is formed on the flange 18 of the rear cross member body 16.
The lower end of the closing plate 17 is connected to the downward flange 19a of the rear cross member body 16.

By connecting the closing plate 17 to the rear cross member body 16, the rear cross member 15 has a closed cross-section structure. Therefore, the front surface portion 20, the upper surface portion 18, and the lower surface portion 19 of the rear cross member body 16 become the “front surface portion”, the “upper surface portion”, and the “lower surface portion” of the rear cross member 15, respectively, and the closing plate 17 becomes the “rear surface portion”. Becomes The outer portion of the upper surface portion 19 of the rear cross member 15 is curved upward, and the closing plate 17 also has a shape corresponding thereto.

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 are flanges 21a, 21b, 21c, 2 that face inward (frontward in FIG. 1) in the front, rear, upper, and lower directions, respectively.
1d, 22a, 22b, 22c, 22d, each of which corresponds to the front surface portion 20, the closing plate 17,
It is 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 a right angle.
In other words, 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. Then, the outer brace 21 is formed into a bent shape 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.

A pair of upper and lower welding bolts 23 as "coupling means" are attached to the rear flanges 21b and 22b of each of the braces 21 and 22 from the front side with their threaded portions facing the rear side. ing. Then, a mounting hole 24 for projecting a threaded portion of the welding bolt 23 is formed at a position of the closing plate 17 corresponding to each welding bolt 23.

The braces 21, 2 having the above structure
Due to 2, 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, and the overall rigidity of the rear cross member 15 is enhanced. 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, and 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
Of each of the rear end flanges 13a are connected to each other.

Reference numeral 25 denotes a stay, which has a cross-section rearward-facing hat shape having front end flanges 26 on the left and right, and flanges 27 formed by bending from the left and right sides at the upper and lower sides. Further, a mounting hole 26a corresponding to the mounting hole 24 of the closing plate 17 is vertically formed in the front end flange 26. The upper and lower flanges 27 of the stay 25,
The upper surface 29a and the rear surface 29b of the bumper force 29 of the rear bumper 28 are spot welded at each spot point S, and the stay 25 is integrated with the bumper force 29. Further, by welding the stay 25 to the bumper reinforcement 29, the stay 2
The front end surface 25a of No. 5 is in contact with the rear surface portion 29c of the bumper reinforcement 29. Further, the work openings 30 are provided on both 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.
Is formed. Incidentally, 31 is a bumper facia.

Therefore, as a method of mounting the rear bumper 28, the stay 2 integrated with the bumper reinforcement 29 is used.
The front end flange 26 of No. 5 is set in the closing plate 17 of the rear cross member 15, and the threaded portion of the welding bolt 23 protruding from the mounting hole 24 of the closing plate 17 is attached to the mounting hole 26a of the front end flange 26 of the stay 25.
Through the work opening 30 of the bumper reinforcement 29, a nut 32 as a "coupling means" is fastened to the welding bolt 23, and the bumper reinforcement 29 is attached to the rear cross member 15. After attaching the bumper reinforcement 29, a bumper fascia 31 is attached to the bumper reinforcement 29, and the bumper reinforcement 29 covers the bumper reinforcement 29.

Since this embodiment has the above structure, it has the following advantages.

Installation workability

Furthermore, since the mounting direction of the nut 32 and the mounting direction of the rear bumper 28 are the same, and the mounting work of the nut 32 can be performed on the outside of the vehicle, the conventional work is performed on the inside of the vehicle. Installation workability is better than. Also, when performing the replacement work of the bumper reinforcement 29, the rear bumper 28 to the bumper fascia 31
Can be removed to easily remove the nut 32 from the work opening 30.

Load transferability

The load F applied to the rear bumper 28 due to the rear collision of the automobile is the bumper reinforcement 29 → stay 2
Since it is linearly transmitted to 5 → braces 21, 22 → rear side member 13, an excessive load F can be received by the entire rear side member 13. Therefore, the load F
It is possible to generate a sufficient reaction force against, and to suppress the deformation of the vehicle body. In particular, in this embodiment, since the front end surface 25a of the stay 25 is in contact with the rear surface portion 29c of the bumper reinforcement 29, the load applied to the welding spot point S can be reduced.

[ Mounting rigidity ]

As shown in FIG. 3, inside the rear cross member 15, the front surface portion 20 and the "rear surface portion" of the rear cross member 15 are provided.
Closing plate 17, left and right brace 2
Since the closed cross-section portion H is formed by 1 and 22, and the stay 25 of the rear bumper 28 is attached to the rear side member 13 via the closed cross-section portion H, the rear bumper 28 is formed.
The mounting rigidity of is improved. Therefore, rattling of the rear bumper 28 due to vibration during traveling can be prevented, and the resistance against lateral and vertical loads applied to the bumper reinforcement 29 is increased.

Waterproof

It is not necessary to form a work opening at a position which is a problem in terms of waterproofness for the mounting work of the rear bumper 28, and the mounting hole 24 formed in the closing plate 17 is also mounted by the welding bolt 23 and the nut 32. It is inevitable that the rear cross member 15 is blocked and water can be surely prevented from entering the rear cross member 15. Therefore, it is not necessary to use a cap or a filler for waterproofing, and the number of parts and the number of working steps can be reduced.

In the above embodiment, the working opening 30 is formed in the bumper reinforcement 29. However, the working opening 30 does not necessarily have to be formed, and depending on the shape of the bumper reinforcement 29, the bumper reinforcement 29 may be used. From the gap between the force 29 and the rear cross member 15, the mounting work can be performed by the bolt / nut means.

[0044]

According to the first aspect of the present invention, the load applied to the rear bumper is linearly transmitted to the bumper reinforcement → the brace → the rear side member, so that the entire rear side member can also receive an excessive load. You can

In addition, since the front cross section of the rear cross member and the closed cross section formed by the left and right braces are formed in the rear cross member, and the bumper reinforcement is attached to the rear side member through the closed cross section, the rear bumper of the rear bumper is attached. Mounting rigidity is improved.

Further, since the rear bumper mounting work can be performed from the outside of the vehicle, the workability of mounting is better than that in the conventional case where the inside of the vehicle is mounted.

In addition, for mounting the rear bumper,
It is not necessary to provide a work opening or the like at a position that poses a problem in terms of waterproofing, and the mounting hole formed in the rear surface of the rear cross member is inevitably blocked by the coupling means. The number of points and work man-hours will not increase.

According to the second aspect of the invention, since the flanges at the upper end and the lower end of the brace are connected to the upper surface portion and the lower surface portion of the rear cross member respectively, the mounting rigidity of the rear bumper is further enhanced.

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 of the rear cross member at a substantially right angle. When the flange facing inward is formed at the upper end of the outer brace, the angle between the flange and the upper portion of the brace becomes substantially right angle, which facilitates connection work of the flange to the upper surface of the rear cross member. That is, when the angle is an acute angle, it becomes difficult to perform connection work by spot welding or the like, but when the angle is substantially right, the work becomes easy.

According to the fourth aspect of the present invention, since the working opening for the coupling means is formed at the rear 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 are different. Match and
The workability of mounting the rear bumper is improved.

[Brief description of 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 vertical cross-sectional view showing a mounted state of a brace in a rear cross member.

FIG. 3 is a cross-sectional view taken along the line SA-SA shown 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 surface part) 20 front surface part 21, 22 brace 23 welding bolt (coupling means) 24 mounting hole 29 bumper reinforcement 32 nut (coupling means)

Claims (4)

[Claims] 1. A front end portion of a rear cross member having a closed cross-section structure is connected to rear end flanges formed on both left and right sides of a rear end portion of a rear side member, and each of the rear end flanges at the front end portion of the rear cross member end portion is connected. The connection part and each corresponding part on the rear surface part are connected by a pair of left and right braces, and a mounting hole is formed at the connection part at the rear end of each brace on the rear surface part of the rear cross member, and the bumper reinforcement is installed as described above. A rear bumper mounting structure for an automobile, characterized in that the rear bumper is mounted through a hole to each rear end of each brace in the rear cross member by a coupling means. 2. A rear bumper mounting structure for an automobile according to claim 1, wherein flanges are formed on the upper and lower ends of the brace, and the flanges are connected to the upper surface and the lower surface of the rear cross member, respectively. 3. An outer portion of an upper surface portion of the rear cross member is curved upward, and an upper portion of the outer brace is bent inward to be connected at a substantially right angle to the curved upper surface portion. The rear bumper mounting structure for an automobile according to claim 2. 4. The vehicle rear bumper mounting structure according to claim 1, wherein a working opening for a coupling means is formed at a position rearward of the mounting hole of the rear cross member in the bumper reinforcement.