JPH0410130Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to the rear body structure of an automobile, and more particularly to a rear bumper and its mounting structure.

Among rear bumpers, some are equipped with a shock absorber for shock absorption, especially as a measure against minor vehicle collisions. This is because the shock absorber also serves as a mounting stay for the bumper, and in the event of a light impact on the car, the shock absorber cushions the impact and does not cause discomfort to the occupants. When released, the bumper is returned to its original position, which has the advantage of preventing the bumper from deforming and deteriorating its appearance (``Complete Book of Automobile Engineering, Volume 13, Passenger Car Body'', April 20, 1982, Sankaido P. .184-188).

Prior Art Fig. 1 is a rear perspective view of an automobile, and Fig. 2 is a sectional view taken along the line A-A in Fig. 1 showing a conventional bumper and its mounting structure, in which the shock absorber 2 is joined to the lower surface of the floor panel 11. A bolt/nut 16 is fixed to the side member 15, and a back bar assembly 4 is fixed to the tip of the rod 3 of the shock absorber 2 with a bolt 5. This back bar assembly 4 serves as the aggregate of the rear bumper 1, and includes a back bar 6 having a U-shaped cross section, and a back bar 6 having a U-shaped cross section.
A closed section is formed with the reinforcement 7 joined to the back of the head. A bumper outer skin 8 made of an elastic material such as rubber or resin is disposed to cover the back bar assembly 4. This bumper outer skin 8 has its upper edge bolted to the rear panel top 9.
The nut 12 is fixed, and the lower edge is left free as shown, or the back bar assembly 4 is fixed to the lower side with a bolt and nut.

With the above structure, in the event of a light collision of a motor vehicle, the back bar assembly 4 of the rear bumper 1 moves backward and the bumper outer skin 8 is elastically deformed, and the shock absorber 2 absorbs the impact. When the external input is released, the shock absorber 2
As a result, the back bar assembly 4 is returned to its original state, and the bumper outer skin 8 is also returned to its original state due to its own elasticity, so that there is no change in appearance.

Problems to be Solved by the Invention By the way, in such a light collision of a car, when the back bar assembly 4 moves backward by the maximum stroke S, as shown by the chain line in FIG. It is necessary to ensure a predetermined clearance δ so that the assembly 4 does not interfere with the vehicle body B.

However, in the conventional configuration, the reinforcement 7 of the back bar assembly 4 is formed flat, and on the other hand, the rear panel upper 9, rear panel lower 10, The joint flange portion 13 of the floor panel 11 protrudes, and the rear panel lower 10 has a bulge portion 14 formed in accordance with the design requirements of the vehicle body and has an uneven shape, so that the clearance δ can be secured. However, if an attempt is made to ensure the stroke S, the protrusion amount l of the rear bumper 1 increases, which increases the overall length of the vehicle body, which is not only disadvantageous during transportation and conveyance, but also meets the demand for reducing the turning radius of the vehicle. This was a huge disadvantage, especially for small cars.

Therefore, in order to avoid an increase in the amount of protrusion of the rear bumper 1, it may be possible to make the back bar assembly 4 smaller, but this would reduce the area of the closed cross section of the back bar assembly 4 and reduce its strength. This creates a new problem of lowering the value.

In addition, in order to avoid an increase in the amount of protrusion of the rear bumper 1, the structure of the rear part of the vehicle body may be changed to offset the positions of the joint flange portion 13 and the back bar assembly 4 in the vertical direction of the vehicle, or the rear panel top may be offset. 9. It is conceivable to shift the rear panel lower 10 and floor panel 11 toward the front of the vehicle, but in the former case, not only would it be necessary to change the joint structure of each panel at the rear of the vehicle body, but the method of change would also require changes. In some cases, this may cause the problem of narrowing the vehicle space and worsening the comfort of the vehicle, and in the latter case, the only result is a narrowing of the vehicle interior space, which is not a good idea in any case.

Means for Solving the Problems In view of the conventional situation, the present invention is designed to improve the strength of the rear bumper without making any changes to the structure of the rear part of the vehicle body, without narrowing the cabin space, and while ensuring the strength of the rear bumper. It is possible to reduce the amount of protrusion from the vehicle body, and even when the impact of a vehicle collision is applied from the top or bottom of the rear bumper.
To provide a rear bumper capable of transmitting impact to a side member without rotating the rear bumper around a mounting rod, and a rear vehicle body structure related to its mounting structure.

Therefore, in order to achieve the above object, the present invention departs from the conventional technical idea of simply forming a concave portion in the part that interferes with the vehicle body when the rear bumper moves, and instead improves the rear bumper, especially the back bar assembly. It is a product with improvements in shape, structure, and installation, and the details of the structure are as shown in the claims of the utility model registration.

Embodiment Hereinafter, an embodiment of the present invention will be described based on FIG. 3, with the same reference numerals attached to the same target parts as in the prior art.

That is, in the present invention, as shown in Fig. 3,
A shock absorber 2 is attached to the side member 15 on the lower surface of the floor panel 11 and the rear panel lower 1.
A back bar assembly 4 is attached via an attachment plate 19 to the rear end 3a of the rod 3, which is fixed to the rear end 3a of the rod 3 by bolts and nuts 16 and is capable of moving in and out of the shock absorber 2. Further, the joint flange 13 between the rear panel upper 9 and the rear panel lower 10 and the lower bulge 14 of the side member 15 of the rear panel lower 10 protrude rearward from the rear end 2a of the shock absorber 2, and the bumper outer skin 8 They are attached to the rear panel upper 9 by bolts and nuts 12 and to the back bar 6c by bolts and nuts 18 so as to cover the back bar assembly 4, respectively.

The mounting plate 19 is formed in a cross-sectional shape that expands toward the bumper outer skin 8 side, and its total width L1
is smaller than the distance L between the joining flange 13 and the bulge 14 and larger than the height of the side member 15.

Further, the back bar assembly 4 has a rear surface portion 6a having a length L2 larger than the distance L, and has a back bar 6 formed in a cross-section shape that widens toward the rear panels 9 and 10. The rain force 7 has a shape that matches the shape of the mounting plate 19 and has a cross section that expands toward the bumper outer skin 8 side. 7
c are respectively attached to the rear surface portion 6a of the back bar 6 to form a substantially trapezoidal closed cross section S1.

Further, when the back bar assembly 4 moves forward, in order not to interfere with the joining flange 13 and the bulging portion 14, the tapered upper surface portion 7b of the reinforcement 7 and the upper surface portion 6b bent toward the front side of the back bar 6, and the rear surface portion 6a, and the tapered lower surface portion 7c of the rain force 7 and the back bar 6.
The lower surface part 6c bent to the front side and the rear surface part 6a
and form a recess 20, respectively.

Furthermore, when attaching the mounting plate 19 to the back bar assembly 4, the tapered upper surface portion 19b of the mounting plate 19 and the tapered upper surface portion 7b of the reinforcement 7 are connected, and the tapered lower surface portion of the mounting plate 19 is 19c and the tapered lower surface portion 7c of the reinforcement 7 are each connected by bolts and nuts 5, which are connecting members.

Note that the bridge 17 includes an upper surface portion 6b of the back bar 6 and a tapered upper surface portion 7b of the reinforcement 7.
This is a member that connects the back bar 6 and prevents the upper surface 6b of the back bar 6 from expanding.

According to the above embodiment structure, when the back bar assembly 4 moves forward, the mounting plate 19 and the front part of the reinforcement 7 enter between the joining flange 13 and the bulging part 14, and the joining flange 13 and the bulge 14 enter the recess 20, so that the mounting plate 19 and the back bar assembly 4 are attached to the joint flange 13.
The back bar assembly 4 can be brought closer to the vehicle body B as a whole, thereby ensuring a predetermined clearance δ and maximizing the movement of the back bar assembly 4 by the stroke S. When the position is set, the protrusion amount _l1 of the bumper 1 can be reduced by the above-mentioned overlap.

Further, since the rain force 7 is formed so that its upper surface portion 7b and lower surface portion 7c are each formed into a substantially tapered cross-sectional shape, and is joined to the back bar 6 to form a substantially trapezoidal closed cross-section S1, it is limited to the inside of the bumper outer skin 8. A sufficient closed cross-sectional area of the back bar assembly 4 can be secured within the space provided,
It is possible to sufficiently secure the strength required for the bumper 1 frame member.

Furthermore, the cross sections of the mounting plate 19 and the reinforcement 7 are formed into substantially matching shapes, so that the tapered upper surface portion 19b of the mounting plate 19 and the tapered upper surface portion 7b of the reinforcement 7 are
The tapered lower surface part 19c of the mounting plate 19 and the tapered lower surface part 7c of the reinforcement 7 are mounted with bolts 5 so that the mounting plate 19 covers the reinforcement 7, so that the impact at the time of a collision is reduced. Even if the impact is applied from above or below the bumper 1, the back bar assembly 4 can reliably transmit the impact to the side member 15 without rotating around the rod 3. In addition, since the mounting plate 19 and the reinforcement 7 are connected at their upper and lower surfaces, respectively, the connecting parts can be moved further rearward, making it possible to further reduce the amount of protrusion _l1 of the bumper 1 and improving the workability of the connection. improves.

Moreover, the structure of the rear part of the vehicle body is the same as the conventional structure (Fig. 2), so there is no need to make any changes, and the practicality of the conventional structure, which does not narrow the cabin space, is not compromised in any way.

Effects of the invention As described above, according to the invention, the closed cross-sectional area of the back bar assembly can be secured sufficiently, and the back bar assembly can be secured while maintaining sufficient strength required as a bumper frame member. When moving forward, the back bar assembly can be brought closer to the vehicle body as a whole. Therefore, if the specified clearance is secured and the maximum travel position of the back bar assembly is set, the bumper The amount of protrusion can be made as small as possible. As a result, the overall length of the vehicle body can be shortened, which is advantageous for transportation and conveyance, and the turning radius can be reduced to improve turning ability.

In addition, even if the impact of a collision is applied from the top or bottom of the bumper, the back bar assembly will not rotate around the rod, and the impact will be reliably transmitted to the side members, and the mounting plate and reinforcement will The connecting portion can be moved further rearward, the amount of protrusion of the bumper can be further reduced, and the connecting workability is improved.

Furthermore, as the amount of protrusion of the bumper is reduced, the outer skin of the bumper can be made smaller, which has a great practical effect of reducing weight and cost.

[Brief explanation of the drawing]

Figure 1 is a rear perspective view of a car, and Figure 2 shows a conventional rear bumper and its mounting structure.
A sectional view taken along the line, FIG. 3, is a sectional view similar to FIG. 2 showing an embodiment of the present invention. 1... Rear bumper, 2... Shock absorber, 2a... Rear end of shock absorber 2, 3
... Rod, 3a ... Rear end of rod, 4 ... Back bar assembly, 5 ... Connection member, 6 ...
Back bar, 6a... Rear part of back bar 6, 7
...Rainforce, 7b...Rainforce 7
Upper surface part, 7c... lower surface part of rain force 7,
8...Bumper outer skin, 9...Rear panel upper, 10...Rear panel lower, 11...Floor panel, 13...Joint flange, 14...Bulging portion,
15...Side member, 19...Mounting plate,
19b...Top surface of mounting plate 19, 19c...
...Lower surface of mounting plate 19, 20...Recess, L
1...Full width of mounting plate 19, L2...Width of back bar 6, L...Joint flange 13 and bulge 1
4 interval, S1...Closed sectional view.

Claims (1)

[Scope of claim for utility model registration] A bumper outer skin 8 disposed at the rear of the rear panel upper 9 and rear panel lower 10, and a back bar assembly 4 disposed inside the bumper outer skin 8.
a shock absorber 2 connected to the back bar assembly 4 and fixed to the side member 15 on the lower surface of the floor panel 11; a rod 3 provided on the shock absorber 2 and capable of moving in and out of the shock absorber 2; a mounting plate 19 attached to the rear end portion 3a to which the back bar assembly 4 is attached;
The joint flange 13 between the side member 15 and the bulge 14 below the side member 15 in the rear panel lower 10 is connected to the rear end 2 of the shock absorber 2.
In the rear body structure that protrudes rearward from point a, the mounting plate 19 is formed in a cross-sectional shape that expands toward the bumper outer skin 8 side, and its full width L1
is formed to be smaller than the distance L between the joining flange 13 and the bulge 14 and larger than the height of the side member 15, while the back bar assembly 4 has a rear surface portion 6a having a length L2 larger than the distance L. The back bar 6 is formed in the shape of a cross section that expands toward the rear panels 9 and 10, and the rain force 7 is located in the front of the back bar 6, matches the mounting plate 19, and expands toward the bumper skin 8. and a tapered upper surface 7b and a tapered lower surface 7c of the reinforcement 7 are respectively attached to the rear surface 6a of the back bar 6 to form a substantially trapezoidal closed cross section S1, and the tapered upper surface of the reinforcement 7 A recess 20 is formed by the portion 7b, the upper surface 6b and the rear surface 6a of the back bar 6, and by the tapered lower surface 7c of the reinforcement 7, the lower surface 6c and the rear surface 6a of the back bar 6, and a mounting plate 19 is formed. The tapered upper surface portion 19b of the reinforcement 7 and the tapered upper surface portion 7b of the reinforcement 7,
Also, the tapered lower surface portion 19c of the mounting plate 19
and a tapered lower surface part 7c of the reinforcement 7 are connected and fixed by a connecting member 5, respectively.