JP4060979B2 - Vehicle bumper - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vehicular bumper that is attached to the front or rear of a passenger car or the like.
[0002]
[Prior art]
A bumper for a vehicle such as a passenger car includes at least a beam portion that exhibits rigidity as a bumper, a fascia portion that is exposed to the outside of the vehicle body, and a bracket that is attached to the vehicle body. Conventionally, these are separate component configurations. It was the target.
However, in recent years, such a bumper for a vehicle has been studied in which these components are integrally formed by blow molding with the aim of reducing the number of components and reducing the weight, as disclosed in JP-A-6-247237. The gazette technique is integrally molded by thermoplastic resin blow molding, has a bumper body and a bracket for mounting the bumper body to a vehicle, and includes a beam part and a facer part in the bumper body. .
[0003]
[Problems to be solved by the invention]
However, the hollow blow molded vehicle bumper disclosed in the above publication has a drawback that the body is deformed due to the impact being applied to the vehicle lower back even in a small collision. For light collisions, it is desirable that it can be absorbed by the bumper without affecting the vehicle body. For a certain degree of impact (light collision), it is economical if it is sufficient to replace the bumper. Otherwise, not only the bumper but also the vehicle must be repaired for every light collision. The conventional vehicle bumper has a tendency that the load input to the lower back becomes high even during a light collision, and the lower back tends to be deformed.
[0004]
SUMMARY OF THE INVENTION An object of the present invention is to provide a vehicular bumper that solves the above-described problems and that does not lead to deformation of the vehicle body during a light collision while maintaining excellent shock absorption.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, the gist of the invention described in claim 1 is a vehicle bumper in which a bumper shell body (P) is integrally formed by blow molding having a hollow portion (O) , and the bumper shell body. The back surface portion (2 ) of (P) forms a flat surface (21) at a position facing the pair of members (5) on both sides of the vehicle, and between the two points of the facing portions of the vehicle member (5). Is divided into a lower half (2b) located in the part facing the vehicle member (5) and an upper half (2a) located in the part facing the vehicle lower back (6). A concave portion is formed from the vehicle side toward the surface portion (1) of the bumper, and the concave bottom is joined to the surface portion (1) to form a joint portion (g ₁ ). recessed V-shape in cross section when viewed toward the shell body surface portion from the vehicle bumper while the rear surface portion to secure the hollow section (O) of (P) (1) Standing rib portion (23a) is provided by forming a separate joint part (g ₂₎ of the surface portion (1), and a hollow portion (O) is lower while leaving the upper half (2a) The vehicle bumper is characterized in that the hollow part (O ) of the half part (2b) is filled with the foam (3) .
The bumper for a vehicle according to a second aspect of the present invention is the bumper for a vehicle according to the first aspect , wherein a bolt (4) or a nut is insert-molded on the flat surface (21) , and the upper half (2a) is connected to the vehicle lower back (6) . The opposing surface is a flat surface (25) and has a substantially rectangular shape in cross section.
[0006]
As in the vehicle bumper of the present invention, when the hollow portion is formed and divided into the upper half portion and the lower half portion, and only the lower half portion is filled with foam and the upper half portion remains the hollow portion, the upper half portion Is less rigid and easily deforms at low loads, and does not damage the lower back in light impacts. If the hollow part (O) of the upper half part (2a) is left as it is, the rigidity is kept low, and it is deformed with a low load so that no load is applied to the vehicle lower back. If it is a certain amount of impact, it can be repaired by replacing the bumper without damaging the lower back. On the other hand, the lower half portion is recessed not only from the joint portion with the upper half portion but also from the vehicle side toward the surface portion of the bumper to form another joint portion with the surface portion. Exerts rigidity and increases power in absorbing shock. In particular, the rear surface portion of the bumper shell body (P) has a hollow portion (O) and is recessed from the vehicle side toward the surface portion (1) of the bumper in a V-shape in a cross-sectional view and the surface portion (1) . If the standing rib portion (23a) is provided by forming another joint portion (g ₂ ) , the standing rib increases the cross-sectional rigidity comparable to that of a conventional bumper beam, and most of the load input to the bumper is here. You will be able to accept it. In the case of a large collision, it provides stable deformation characteristics and exhibits excellent shock absorption, effectively transmitting the impact load to vehicle members. Since the standing rib of the recess is V-shaped in cross-section, it acts as a standing wall and exerts the above-mentioned rigidity, while mitigating the impact load up to a certain level by elastic deformation and strives to maintain the shape of the bumper body. Furthermore, since the hollow part of the lower half is filled with the foam, the impact can be further alleviated. In addition, when the flat surface (21) is formed at a position facing the pair of members (5) on both sides of the vehicle , the flat surface serves as a conventional mounting bracket.
As in the second aspect of the invention, when the upper half (2a) has a flat surface (25) facing the vehicle lower back (6) and has a substantially rectangular cross section, the cross-sectional rigidity of the upper half When the load is low, the low-profile section is deformed and the load is not applied to the vehicle lower back. Reduce the load on the vehicle lower back at the time of collision, and concentrate the load on the vehicle members. When a low load is applied to the bumper, the lower half is filled with foam while the upper half remains hollow and has a cross-sectionally R shape, so that the rigidity is low and the lower back is not damaged. Only bumper damage and only bumper replacement can be done.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of a vehicle bumper according to the present invention will be described in detail. 1 to 5 show an embodiment of a vehicle bumper according to the present invention. FIG. 1 is an overall perspective view of the rear portion of the vehicle and the vehicle bumper. FIG. 2 is a cross-sectional view of a portion A in FIG. 4 is a cross-sectional view of a portion different from the cross-sectional view of FIG. 1B, and FIG. 5 is a schematic vertical cross-sectional view of the vehicle bumper in FIG. This is applied to the rear bumper of passenger cars.
[0008]
The bumper for a vehicle has a bumper shell main body P formed by blow molding, and includes a front surface portion 1 that serves as a design surface of the bumper and a rear surface portion 2 on the vehicle side, and is further attached to the vehicle member 5 on the rear surface portion 2. The bolt 4 is insert-molded.
The bumper shell main body P includes a front surface portion 1 and a back surface portion 2. The surface portion 1 has a uniform cross section having an arc shape as shown in FIG. 1 and forms a facer portion 1a exposed to the outside of the vehicle body.
[0009]
The back surface 2 of the bumper shell main body P is a rectangular flat surface 21 at a position facing both members 5 so that the bumper shell main body P can be stably applied to the pair of members 5 and 5 on both sides of the vehicle. , 21 are formed (FIG. 2). The flat surface 21 serves as a conventional mounting bracket. Reference numeral 51 denotes an insertion hole of the member 5 provided in the body 8. Bolts 4 for attaching the bumper shell body P to the member 5 are inserted and implanted in the flat surface 21 during blow molding. Here, the bolt 4 is insert-molded, but a nut may be substituted for the bolt 4.
[0010]
The back surface portion 2 of the bumper shell main body is joined to the front surface portion 1 while forming the hollow portion O while forming the hollow portion O with the front surface portion 1. A region in the vehicle width direction connecting two points of the facing portions (flat surface 21) of the vehicle members 5 and 5 and positioned at a portion facing the lower half 2b located at a portion facing the vehicle member 5 and the vehicle lower back 6. The upper half 2a is recessed into the upper and lower parts 2a from the vehicle side toward the surface 1 of the bumper, and the bottom of the bump is joined to the surface 1 to form a joint part g1. As shown in FIG. 2, even at the position facing the member 5 (part A), the flat surface 21 is formed and the upper half 2a and the lower half 2b are divided into almost equal halves. The back surface portion 2 is formed by joining the groove bottom of the recess 23 to the surface portion 1 at the time of blow molding and partitioning it into two hollow portions O with the surface portion 1 and dividing it into an upper half portion 2a and a lower half portion 2b. Yes. Further, the back surface portion 2 is a vehicle width region connecting the flat surface 21 and is recessed in the lower half region from the vehicle side toward the surface portion 1 of the bumper in addition to the joint portion g1. Are formed (FIG. 3). The back surface portion 2 is recessed in a V shape in a cross-sectional view toward the surface portion 1 while securing the hollow portion O between the surface portion 1 and the raised rib portion 23a of these recesses exhibits rigidity as a bumper. Play the role of the beam part.
[0011]
In forming the joint portion g1 by recessing the back surface portion 2, the upper half portion 2a has a flat surface 25 facing the lower back 6 and has a substantially cross-sectional shape in cross section. Lowering the cross section stiffness of the upper half 2a, because the load on the vehicle lower back 6 is deformed section B-shaped portion at a low load so not much whether al.
On the other hand, the lower half 2b has a substantially B-shaped cross section as shown in FIG. By forming a B shape having a plurality of (two) hollow portions O, the standing ribs 23a of the recesses 23 have a cross-sectional rigidity comparable to that of a conventional bumper beam, so that most of the load input to the bumper can be received here. It becomes like this. In the case of a large collision, stable deformation characteristics are obtained and excellent shock absorption is exhibited, and the impact load is effectively transmitted to the vehicle member 5. Since the standing rib 23a of the recess 23 is V-shaped in cross-section, the impact load up to a certain level is reduced by elastic deformation while maintaining the rigidity as a standing wall, and the shape retention of the bumper body P is maintained. Strive.
Two joint portions g2 in the lower half region can be provided as shown in FIG. 4 to further increase the cross-sectional rigidity. A connecting portion 22 that connects the two flat surfaces 21 in the vehicle width direction is formed, a concave portion 23 is provided with the two connecting portions as two ridges, and a bumper from the vehicle side is provided at a vertical position in contact with both the flat surfaces 21 and the connecting portion 22. A concave portion 23 and a joint portion g2 are provided toward the front surface portion 1 of the substrate. Of course, as the joining portion g2 increases, blow molding becomes difficult, so the number of joining portions g2 remains at most about 2 to 3.
[0012]
By the way, with respect to the upper half 2a, in order to make the load input to the lower back 6 as low as possible, it is preferable to make the thickness of the cross-sectionally R-shaped part thinner than that of the lower half 2b. However, the bumper shell main body P can use the circumferential parison or the eccentric core at the time of blow molding to make the thickness of the upper half 2a smaller than the thickness of the lower half 2b. is there. When the thickness of the B-shaped section is reduced, the bumper shell body P is integrally formed by blow molding, so the overall thickness of the bumper also decreases, and the cross section that must serve as a bumper beam is almost The thickness of the B-shaped part is also reduced. The B-shaped part must increase the rigidity.
Therefore, in the present invention, the foam 3 is filled in the B-shaped portion, that is, the hollow portion O of the lower half 2b.
[0013]
The foam 3 is filled only in the hollow part O of the lower half part 2b while leaving the hollow part O of the upper half part 2a as it is.
For the foam 3, for example, hard urethane, foam beads such as polypropylene, polystyrene, polyphenylene oxide (modified PPO) are used. In view of recyclability, foamed polypropylene is preferable. The filling of the foam 3 into the hollow portion O is (1) a method of filling urethane or polypropylene beads from the blow pin hole of the finished bumper, or (2) molding the bumper shell body and cooling the foam during the cooling. 3 is carried out using known means such as a method of filling 3 (for example, JP-A-6-166112).
[0014]
By filling the lower half 2b with the foam 3, the lower half 2b is hard to be deformed and the rigidity is easily maintained, and the impact absorbing power of the bumper is increased. The foam itself also has the characteristic of mitigating impact as an energy absorber. The reason why the foam 3 is not inserted into the hollow portion O of the upper half 2a is to keep the rigidity low and to deform it with a low load so that no load is applied to the vehicle lower back 6. If the impact is to some extent, the aim is to complete the repair by simply replacing the bumper without damaging the lower back 6. In recent years, the upper half 2a of the bumper has a strong design element, and if it is established as a design, the bumper's upper half 2a has a structure in which the shock absorbing capacity of the bumper is obtained in the lower half 2b.
[0015]
The vehicular bumper configured in this way suppresses the load on the vehicle lower back 6 at the time of a collision and concentrates the load on the vehicle member 5.
When a low load is applied to the bumper, the lower half 2b is filled with the foam 3 and the upper half 2a remains hollow and has a square cross section. Absent. Only bumper damage and only bumper replacement can be done.
On the other hand, when a large impact is applied to the bumper, the standing rib 23a of the recess 23 exhibits rigidity and serves as a beam portion. When the bumper receives an impact, the impact load is reliably transmitted to the vehicle member 5 via the standing rib 23a and the flat surface 21 which are beam portions. In the present invention, since the foam 3 is filled in the hollow portion O of the lower half 2b, the shock absorbing power by the foam 3 is further increased.
[0016]
In addition, in this invention, it is not restricted to what is shown to the said embodiment, According to the objective and a use, it can change variously in the range of this invention. The shape, size, and the like of the front surface portion 1, the back surface portion 2, the flat surface 21, the concave portion 23, the bolt 4, and the like can be appropriately selected according to the application.
[0017]
【The invention's effect】
As described above, the vehicular bumper of the present invention has excellent shock absorbing power and improves safety, but at the time of a light collision, it only damages the bumper and does not cause deformation of the vehicle body such as the lower back. It will be beneficial.
[Brief description of the drawings]
FIG. 1 is an overall perspective view of a vehicle bumper according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view of part A in FIG.
3 is a cross-sectional view of a portion B in FIG.
4 is a cross-sectional view of an aspect different from the B cross-sectional view of FIG.
FIG. 5 is a schematic longitudinal sectional view of the vehicle bumper of FIG. 4;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Front surface part 2 Back surface part 2a Upper half part 2b Lower half part
21 Flat surface 23 Recess
23a Standing rib part (standing rib)
25 Flat surface 3 Foam
4 Bolt 5 member (vehicle member)
6 Vehicle lower back O Hollow part P Bumper shell body g1, g2 Joint part

Claims (2)

Bumper shell body (P) is a vehicle bumper formed integrally by blow molding having a hollow portion (O) ,
The back surface portion (2) of the bumper shell main body (P) forms a flat surface (21) at a position facing the pair of members (5) on both sides of the vehicle, and the opposite portion of the vehicle member (5) . In the region in the vehicle width direction connecting two points, a lower half (2b) located at a portion facing the vehicle member (5) and an upper half (2a) located at a portion facing the vehicle lower back (6) So as to be divided into a bumper surface (1) so that the bottom of the bumper is joined to the surface portion (1) to form a joined portion (g ₁ ) , and the lower half region on the surface portion recessed into a V-shape in cross section view the backside portion toward the vehicle while securing a hollow section (O) to the surface portion of the bumper (1) of the bumper shell body (P) and (1) By forming another joint portion (g ₂ ) , the standing rib portion (23a) is provided, and the hollow portion (O) of the upper half portion (2a ) is left as it is, while the lower half portion (2b) hollow portion (O) Vehicle bumper, characterized in that so as to fill foam (3). Flat surface (twenty one) To bolt (Four) Or the nut is insert molded and the upper half (2a) Vehicle lower back (6) The surface facing the flat surface (twenty five) The vehicular bumper according to claim 1, which has a substantially rectangular shape in cross section.

Images