JP3229568B2 - Bumper reinforcement - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bumper reinforcement disposed in a bumper face of a bumper of a vehicle such as an automobile.

[0002]

2. Description of the Related Art Conventionally, as a bumper structure for a vehicle such as an automobile, a bumper reinforcement as a reinforcing member is arranged inside a bumper face, and an impact energy absorber made of, for example, a urethane resin foam or the like is interposed between both. The arrangement is generally well known. In recent years, for the purpose of reducing the number of parts and simplifying the structure and reducing the manufacturing cost, the bumper reinforcement is made to have an impact energy absorbing property, and the bumper reinforcement is combined with the bumper face. It is considered to constitute a bumper. In this case, the bumper reinforcement is generally formed of a synthetic resin.

As a bumper of this type, for example, Japanese Utility Model Laid-Open Publication No. Sho 63-166855 discloses a bumper reinforcement in which the cross-sectional shape is formed into a U-shape and the open end side of the U-shape faces forward. There is disclosed an arrangement which is arranged on the rear side of the face and which is fixed to each other using an adhesive.

[0004]

However, when the bumper face and the bumper reinforcement are bonded and fixed as in the above-described conventional method, a bonding step that requires troublesome time management such as drying time of the adhesive is required. In addition, even if only the bumper face is damaged, it is necessary to replace the entire bumper including the bumper reinforcement, and generally, a metal bracket for mounting to the vehicle body side member must be installed inside the bumper reinforcement in advance. The metal bracket cannot be removed at the time of disposal, so if the bumper reinforcement is made of synthetic resin, there are disadvantages such as poor recyclability. .

With respect to bumper performance at the time of a vehicle collision, when a collision load is input to the bumper face, the smaller the amount of rearward displacement of the rear surface of the reinforcement (particularly, the rear surface of the central portion in the vehicle width direction), the smaller the vehicle body. Preferred for protection, for example, PART
581 defines the so-called pendulum test. Various structures for improving the performance have been considered, but it is required to achieve the structure while minimizing the complexity of the structure and the increase in the manufacturing cost.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a bumper reinforcement that can be detachably assembled to a bumper face and that can improve the bumper performance at the time of a vehicle collision with a relatively simple structure. It was done as.

[0007]

For this reason, the invention according to claim 1 of the present application (hereinafter referred to as a first invention) has a substantially reverse cross-section which constitutes a bumper in combination with a bumper face having a substantially U-shaped cross section. A U-shaped bumper reinforcement having a plurality of longitudinal reinforcing ribs extending in the vertical direction and connecting an upper surface portion and a lower surface portion of the bumper reinforcement, and a portion partitioned by the vertical reinforcing ribs. Of at least predetermined ones, diagonal reinforcing ribs extending in a diagonal direction within the part, and diagonally extending and connecting the vertical reinforcing ribs on both sides of the part are arranged inside and integrally molded, Each longitudinal reinforcing rib and each diagonal reinforcing rib are formed such that the end on the opening side of the bumper reinforcement is substantially concavely bowed, and the opening side having a substantially inverted U-shaped cross section is formed on the bumper face. Capable assembled removably in the opening of the U-shaped cross section of the bumper face in a state towards,
This is to constitute an assembly type bumper.

Further, the invention according to claim 2 of the present application (hereinafter referred to as the invention)
According to a second aspect of the present invention, in the bumper reinforcement according to the first aspect, at least predetermined portions among the portions partitioned by the vertical reinforcing ribs include the oblique reinforcing ribs one by one in the portions. Provided with a flexural modulus of 18500 kgf / cm ² or more and a flexural strength of 400
It is characterized by being molded using a synthetic resin material having mechanical properties of not less than kgf / cm ² and tensile elongation of not less than 80%. Here, the mechanical properties (flexural modulus, flexural strength and tensile elongation) of the synthetic resin material for forming the bumper reinforcement are defined as described above at least in the portion partitioned by the longitudinal reinforcing ribs. In the case of a bumper reinforcement in which predetermined diagonal reinforcing ribs are provided in the portion for a predetermined one,
If each of the characteristics is less than the above value, the bumper performance at the time of a vehicle collision cannot be sufficiently improved.

Further, the invention according to claim 3 of the present application (hereinafter referred to as “the invention”)
According to a third aspect of the present invention, in the bumper reinforcement according to the first aspect of the invention, at least a predetermined one of the portions partitioned by the longitudinal reinforcing ribs has two obliquely intersecting portions intersecting each other within the portion. It is provided that the reinforcing ribs are provided, and the bending elastic modulus is 18000 kgf / cm ² or more, the bending strength is 260 kgf / cm ² or more, and the tensile elongation is 80% or more. It is a characteristic. Here, the mechanical properties (flexural modulus, flexural strength and tensile elongation) of the synthetic resin material for forming the bumper reinforcement are defined as described above at least in the portion partitioned by the longitudinal reinforcing ribs. In the case of a bumper reinforcement in which two oblique reinforcing ribs intersecting each other are provided in the corresponding portion, for each characteristic, if each of the characteristics is less than the above value, the bumper performance at the time of a vehicle collision is improved. This is because it cannot be achieved sufficiently.

[0010]

[0011]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. First, a first embodiment will be described. As shown in FIG. 1, a bumper 1 according to a first embodiment of the present invention is a bumper face 10 forming a skin of the bumper 1 and a reinforcing body of the bumper 1, and also has an impact energy at the time of a vehicle collision. And a bumper reinforcement 20 to be absorbed. That is, in the bumper 1 according to the present embodiment, an impact energy absorber made of, for example, a urethane resin foam or the like is not particularly provided, and the bumper reinforcement 20 is configured as follows.
It plays the role of both a reinforcing body and an impact energy absorber, reducing the number of parts and simplifying the structure.

As shown in FIG. 2, the bumper face 1
Reference numeral 0 denotes a substantially U-shaped cross section of the upper surface 11, the lower surface 12, and the front 13 by, for example, injection molding using a synthetic resin material. On the other hand, the bumper reinforcement 20 includes an upper surface 21, a lower surface 22, and a rear surface 2.
3 and a substantially U-shaped cross section, and is formed by using, for example, an injection molding method using a predetermined synthetic resin material as described in detail later.

This bumper reinforcement 20 is:
The opening side of the substantially inverted U-shaped cross section corresponds to the bumper face 10.
The bumper face 10 is assembled into the opening of the U-shaped cross section of the bumper face 10 with the side faced. Note that a plurality of support ribs 27 are provided above the upper surface portion 21 of the bumper reinforcement 20 to prevent sagging deformation of the upper surface portion 11 of the bumper face 10 when the bumper face 10 is assembled.
In order to prevent the support ribs 27 from falling down, a horizontal rib 28 connecting the support ribs 27 is provided. Then, the upper flange 21f of the bumper reinforcement 20 and the upper flange 1 of the bumper face 10
1f and the lower flange 12f of the bumper face 10 is connected to the bumper reinforcement 20.
After being in contact with the lower surface portion 22, the two members 10, 20 are fastened and fixed to each other by the screw members 6, 7.

The bumper 1 assembled as described above
Can be easily removed by unscrewing the screw members 6 and 7 and the bumper face 10 and the bumper reinforcement 2.
It can be decomposed into zero. That is, the bumper reinforcement 20 is removably assembled to the bumper face 10 to form the assembled bumper 1. The bumper 1 assembled as described above
The rear surface 23 of the bumper reinforcement 20 abuts on a vehicle body-side member (not shown) at both ends in the vehicle width direction, and is fastened and fixed to the vehicle body-side member using, for example, a screw member. Fixed for. At this time, when the screw member is applied, a metal bracket (not shown) for attachment to the vehicle body side member is used, and this metal bracket is detached inside the bumper reinforcement 20 (inside the rear surface portion 23). It is provided as possible.

By assembling the bumper 1 in this manner, the need for a troublesome bonding process requiring time management as in the case where the two 10, 20 are conventionally bonded and fixed is not required, and only the bumper face 10 is used. In the case of damage, only the face 10 needs to be replaced with a new one without replacing the entire bumper 1. Also, a metal bracket (not shown) for attachment to the vehicle body side member can be detachably provided inside the bumper reinforcement 20, and the metal bracket can be removed at the time of disposal. Even if the reinforcement 20 is made of a synthetic resin, it is possible to prevent metal from being mixed into the waste material, and to improve the recyclability.

In this embodiment, a plate-shaped vertical rib 24 as a vertical reinforcing rib extending in the vertical direction is provided inside the bumper reinforcement 20 (ie, in the opening having a substantially inverted U-shaped cross section). A plate-shaped oblique rib 25 as an oblique reinforcing rib extending in an oblique direction is provided integrally with the bumper reinforcement 20. The above vertical rib 2
4 (e.g., about 3 to 4 mm) is provided at predetermined intervals (e.g., about 100 mm) in a range excluding both ends of the bumper reinforcement 20 (e.g., about 3 to 4 mm).
mm) and bumper reinforcement 2
The upper surface 21, the lower surface 22, and preferably the rear surface 23 are connected to each other. The oblique rib 25
Are arranged in a portion partitioned by each vertical rib 24,
The longitudinal ribs 24 on both sides are provided so as to extend diagonally, and are connected to the longitudinal ribs 24 and preferably to the rear surface portion 23. The pattern of the slanted ribs 25 in the direction of inclination is not limited to the example of FIG. 1, and the slanted ribs 25 may be inclined in accordance with other appropriate patterns.

As described above, by providing the reinforcing ribs 24 and 25 in the bumper reinforcement 20, the vertical ribs 24 allow the bumper reinforcement 20 to be provided.
The rearward displacement of the rear surface can be suppressed.
0 can be suppressed, and the longitudinal ribs 24 can be prevented from falling down. That is, the integrally formed reinforcing rib 2
With a relatively simple configuration having only 4, 25, the bumper performance at the time of a vehicle collision can be improved.

The vertical ribs 24 and the oblique ribs 25 are more preferably formed so that the opening-side end of the bumper reinforcement 20 is substantially bowed, so that the bumper 1 can be mounted on the bumper 1 from the front. When a collision load is applied, it is possible to effectively prevent the ribs 24 and 25 from being first cracked and the reinforcing effect from being reduced.

In the present embodiment, when the bumper reinforcement 20 is manufactured, a machine made of a synthetic resin material used for molding the bumper reinforcement 20 so that good bumper performance at the time of a vehicle collision can be obtained. A test to evaluate the mechanical properties was performed. Hereinafter, this evaluation test will be described. The test was performed on various materials having different characteristic values for each item of flexural modulus, flexural strength and tensile elongation. Using each of these materials, a bumper reinforcement 20 as shown in FIG. 1 was formed, and the above three items of the mechanical characteristic values were measured. The test of the mechanical property values was performed in accordance with ASTM D790 for the flexural modulus and the flexural strength, and in accordance with ASTM D638 for the tensile elongation.
Then, each formed bumper reinforcement 20
For example, a pendulum test was performed under the condition that the vehicle weight was 1200 kg, and the quality was determined. Table 1 shows the test results. The main dimensions of the bumper reinforcement 20 used in this test were as follows.・ Length: L ≒ 1400mm ・ Width: W ≒ 130mm ・ Height: H ≒ 230mm

[0020]

[Table 1]

In the above test, the examples of the present invention have a flexural modulus of 18500 kgf / cm ² or more and a flexural strength of 4
As a material satisfying the conditions of mechanical properties of 00 kgf / cm ² or more and a tensile elongation of 80% or more, polycarbonate /
Polybutylene terephthalate (PC / PBT) resin (sample 1) and polypropylene (PP) resin (sample 2) were used. As comparative examples, polyethylene (PE) resin (sample 3) and polypropylene (P
P) Resin (sample 5) and glass reinforced fiber (GF)
Was used (Sample 4).

From the test results in Table 1, it was confirmed that good (も の) results were obtained in the pendulum test for those satisfying the above conditions of mechanical properties. on the other hand,
Materials that did not satisfy the above-mentioned requirements for mechanical properties were found to be unsatisfactory (△) or poor (×) in the pendulum test.

As described above, in the case where the oblique ribs 25 are provided one by one in the portion partitioned by the vertical ribs 24, the mechanical characteristics (the flexural modulus is 18500 kg)
f / cm ² or more, bending strength 400 kgf / cm ² or more,
By molding a bumper reinforcement using a synthetic resin material having a tensile elongation of 80% or more), good results can be achieved in the pendulum test, and bumper performance at the time of a vehicle collision can be improved. In the above example, the diagonal ribs 25 are provided for all of the parts partitioned by the vertical ribs in a range excluding both end portions of the bumper reinforcement 20,
When the strength characteristics required for the bumper reinforcement are relatively low, the oblique rib 25 is provided only for one or more predetermined parts among the parts partitioned by the vertical ribs. Is also good.

Next, a second embodiment of the present invention will be described. The second embodiment is different from the first embodiment in that the diagonal ribs 25 are provided one by one in a portion partitioned by the vertical ribs 24, 24. At least a predetermined one is provided with two oblique ribs intersecting each other inside thereof. In the following description, the same components as those in the first embodiment are denoted by the same reference numerals, and further description is omitted.

As shown in FIG. 3, in the bumper reinforcement 50 of the bumper 41 according to the present embodiment, in the portion (segment) partitioned by the vertical ribs 24, 24, the vertical ribs 24 on both sides of the portion are provided. Are connected diagonally so as to be connected to both the vertical ribs 24 and preferably to the rear surface portion 23. The first slanted ribs 55 have the same slanting direction as that shown in FIG. Are arranged, and of the portions separated by the vertical ribs in the range excluding both end portions of the bumper reinforcement 50, the remaining portions except for the two central ones intersect with the first oblique ribs 55. A second oblique rib 56 is provided.
That is, these portions are provided with two oblique ribs 55 and 56 that cross each other.

As described above, in addition to the first oblique rib 55,
By providing the second oblique rib 56 intersecting with this, the bumper reinforcement 50 is more effectively reinforced than in the case of the first embodiment.
Note that the second oblique ribs 56 may be provided for all the parts partitioned by the vertical ribs. Further, the first and second oblique ribs 55 and 56 and the vertical rib 24 are more preferably formed such that the ends on the opening side of the bumper reinforcement 50 are substantially arcuate as in the case of the first embodiment. It is formed so as to dent into a shape,
When a collision load acts on the bumper 41 from the front, the rib 2
4, 55, 56 can be effectively prevented from first being cracked and the reinforcing effect being reduced.

The bumper reinforcement 50 having the rib structure as described above was molded using the same resin material as that used in the evaluation test (pendulum test) in the first embodiment. Then, using each of the obtained samples (samples 6 to 10), a pendulum test was performed under the same conditions as those in the first embodiment, and the quality was determined. The main dimensions of the bumper reinforcement were the same as those in the first embodiment. Table 2 shows the test results.

[0028]

[Table 2]

From the results shown in Table 2, the same materials (Samples 6 and 7) as Samples 1 and 2 which showed good (○) results in the pendulum test in the first embodiment were also used. Good results were also obtained in this test, and samples using the same materials as those of Samples 4 and 5 which had poor results (×) in the pendulum test in the first embodiment (Samples 9 and 10) ) Was also poor (x) in this test. However, in the pendulum test in the first embodiment, the sample 8 molded using a polyethylene (PE) resin, which was unsatisfactory (△) as the material of the sample 3, was excellent in the second embodiment. It was found that (を) results were obtained.

As described above, when two oblique ribs 55 and 56 intersecting with each other are provided inside a predetermined one of the portions partitioned by the vertical ribs 24, the oblique reinforcing ribs 25 are provided one by one. , A higher reinforcing effect is obtained and mechanical properties lower than those in the first embodiment (the flexural modulus is 18000 kgf / cm ² or more,
Flexural strength of 260 kgf / cm ² or more, tensile elongation of 80
% Or more) of the synthetic resin material, good results can be achieved in the pendulum test, and the bumper performance at the time of a vehicle collision can be improved. Therefore, a commercially available and relatively inexpensive polyethylene (PE) resin can be used as the material resin of the bumper reinforcement 50.

The present invention is not limited to the above-described embodiment, but may be modified without departing from the scope of the invention.
It goes without saying that various improvements or design changes are possible.

[0032]

According to the first aspect of the present invention, the above-mentioned bumper reinforcement is removably assembled in the opening of the U-shaped cross section of the bumper face to form an assembling type bumper. In addition to eliminating the need for a time-consuming bonding process that requires time management, such as the case where the adhesive is fixed, if the bumper face is damaged, only the face needs to be replaced with a new one without replacing the entire bumper. Also, a metal bracket for mounting to the vehicle body side member can be detachably provided inside the bumper reinforcement, and this metal bracket can be removed at the time of disposal, so that the bumper reinforcement is made of synthetic resin. When made, it is possible to enhance the recyclability. In addition, the vertical reinforcing ribs extending in the vertical direction and the diagonal reinforcing ribs extending in the diagonal direction are arranged inside and integrally molded, so that the rearward displacement of the rear surface of the bumper reinforcement is suppressed by the vertical reinforcing ribs. In addition, the torsion of the bumper reinforcement can be suppressed by the reinforcing ribs in the oblique direction, and the reinforcing ribs in the vertical direction can be prevented from falling down. That is, the bumper performance at the time of a vehicle collision can be improved with a relatively simple configuration in which only the integrally formed reinforcing rib is provided.
Furthermore, since the above-mentioned longitudinal reinforcing ribs and diagonal reinforcing ribs are formed so that the end on the opening side of the bumper reinforcement is substantially concavely bent, when a collision load is applied to the bumper from the front, these are formed. It is possible to effectively prevent the first generation of cracks in the reinforcing ribs and the reduction of the reinforcing effect.

Further, according to the second aspect of the present invention, basically the same effects as those of the first aspect can be obtained. In particular, for at least a predetermined portion of the portions partitioned by the longitudinal reinforcing ribs, when the oblique reinforcing ribs are provided one by one in the portion, the mechanical characteristics (the bending elastic modulus is 18500 kgf / cm ^2). As described above, by forming the bumper reinforcement using a synthetic resin material having a bending strength of 400 kgf / cm ² or more and a tensile elongation of 80% or more, the bumper performance at the time of a vehicle collision can be improved. .

Further, according to the third aspect of the present invention, basically the same effects as those of the first aspect can be obtained. In particular, at least a predetermined portion of the portion partitioned by the vertical reinforcing ribs is provided with two diagonal reinforcing ribs intersecting each other in the portion. Thus, a higher reinforcing effect can be obtained. In this case, bumper reinforcement is performed using a synthetic resin material having the above-mentioned mechanical properties (a flexural modulus of 18000 kgf / cm ² or more, a flexural strength of 260 kgf / cm ² or more, and a tensile elongation of 80% or more). By molding the bumper, it is possible to improve the bumper performance at the time of a vehicle collision.

[0035]

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a bumper according to a first embodiment of the present invention.

FIG. 2 is an explanatory longitudinal sectional view taken along the line AA of FIG. 1;

FIG. 3 is an exploded perspective view of a bumper according to a second embodiment of the present invention.

[Explanation of symbols]

 1,41 ... Bumper 10 ... Bumper face 20,50 ... Bumper reinforcement 24 ... Vertical rib 25,55,56 ... Diagonal rib

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-227750 (JP, A) JP-A-3-224850 (JP, A) JP-A 8-164805 (JP, A) JP-A 8- 2351 (JP, A) JP-A-7-172253 (JP, A) JP-A-4-252754 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B60R 19/18 B60R 19 / 04

Claims (3)

(57) [Claims] 1. A bumper reinforcement having a substantially inverted U-shaped cross section which is combined with a bumper face having a substantially U-shaped cross section to form a bumper, wherein the upper surface and the lower surface of the bumper reinforcement extend vertically. A plurality of vertical reinforcing ribs are provided to connect the vertical reinforcing ribs, and at least a predetermined one of the portions partitioned by the vertical reinforcing ribs extends diagonally in the portion, and the vertical reinforcing ribs on both sides of the portion are provided. Diagonal reinforcing ribs that are diagonally spanned and connected are provided inside and integrally molded, and each of the vertical reinforcing ribs and each diagonal reinforcing rib has a substantially arcuate end on the opening side of the bumper reinforcement. The bumper face is formed so as to be recessed, and is removably assembled in the U-shaped cross-section opening of the bumper face with the opening side of the substantially inverted U-shaped section facing the bumper face side. And a bumper reinforcement, which constitutes an assembling type bumper. 2. The oblique reinforcing ribs are provided one by one in at least predetermined portions of the portions partitioned by the longitudinal reinforcing ribs, and the bending elastic modulus is 18,500.
kgf / cm ² or more, a bending strength of 400 kgf / cm ² or more, a tensile elongation according to claim 1, characterized by being molded using a synthetic resin material having 80% or more of the mechanical properties bumper reinforcement Force. 3. At least a predetermined portion of the portion partitioned by the longitudinal reinforcing ribs is provided with two oblique reinforcing ribs crossing each other in the portion, and has a flexural modulus of 18000 kgf / cm ² or more, Flexural strength 260k
The bumper reinforcement according to claim 1, wherein the bumper reinforcement is molded using a synthetic resin material having mechanical properties of gf / cm ² or more and a tensile elongation of 80% or more.