JP2006123892A - Impact absorbing body for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an impact absorbing body having excellent design property for a vehicle capable of not only absorbing a high impact (≥20 kN) at a collision and a contact with other vehicle or other object but also coping with a low impact (≤5 kN). <P>SOLUTION: The impact absorbing body 1 of the car is interposed between a bumper fascia 2 and a car body to absorb the impact, and includes a bumper beam 3 arranged on a car body side, and a hollow body arranged on the bumper fascia 2 side. A plurality of recessed ribs consisting of recessed ribs 5 and other recessed ribs 6 which are opposite to each other, recessed inwardly and fused to each other are formed in a first wall 8 on the bumper fascia 2 side of the hollow body 4 and a second wall 9 on the bumper beam side. A connection rib 26 rising in the advancing direction of the car is interposed between the adjacent recessed ribs. The recessed ribs are arranged on the imaginary line, and the connection ribs 26 are formed on the imaginary line. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention is an impact absorber that is mounted on at least one of the front and rear parts of an automobile, and is an automobile impact that can absorb and mitigate a wide range of impact values when colliding with or contacting other automobiles or other objects. It relates to an absorber.

  Bumpers as shock absorbing mechanisms for absorbing and mitigating shocks at the time of collision and contact with other automobiles or other objects are installed in the front and rear parts of the automobile. As a conventional bumper, a bent steel plate was used. However, in recent years, as the level of requirements for car design has increased and as safety performance has been improved and the grace of the outer shape has been pursued, bumpers have also been required to match body design in terms of shape, color, etc. It was.

  Such a bumper covers a bumper with a bumper fascia made of a thermoplastic plastic, and an impact absorber is disposed inside the bumper. The bumper fascia is formed by injection molding or stamping molding of polypropylene or other thermoplastics. In recent years, in consideration of recyclability at the time of disposal of automobiles, a polymer alloy of polypropylene with another composite resin has been proposed. And although many forms are employ | adopted for the impact absorber from the surface of performance and cost, a common form is a form centering on a bumper beam.

  As a bumper beam, a bent steel plate as disclosed in JP-A-6-255433 and JP-A-6-328988 has been used in many cases. Synthetic resin bumper beams reinforced with fibers such as glass fibers and carbon fibers as disclosed in Japanese Patent Nos. 344837, 11-34140, and 2-299947 are also beginning to be used.

  These bumper beams are mainly covered with a bumper fascia, and some of them are disclosed in Japanese Utility Model Publication Nos. 56-103349 and 57-32555. A foam for energy absorption may be interposed between the bumper fascia.

This blow-molded bumper is also proposed to be reinforced with a bumper beam as disclosed in Japanese Utility Model Publication No. 4-33165.
JP-A-6-255433 JP-A-6-328988 JP-A-6-344837 JP-A-11-34140 JP-A-2-299947 Japanese Utility Model Publication No. 56-103349 Japanese Utility Model Publication No.57-32555 Japanese Utility Model Publication 4-33165

  The conventional bumper system can absorb and mitigate a high impact value (20 kN or more) at the time of collision or contact with another automobile or another object, but absorbs and mitigates a low impact value (5 kN or less). I can't.

  Therefore, the present invention not only absorbs high impact values (20 kN or more) at the time of collision or contact with other automobiles or other objects, but also supports low impact values (5 kN or less, particularly 3 kN to 5 kN). An object of the present invention is to obtain an automobile shock absorber having excellent design.

  In order to achieve the above object, an automobile shock absorber according to claim 1 is an automobile shock absorber that is interposed between a bumper fascia and a vehicle body and absorbs an impact received by the bumper fascia. A bumper beam made of metal or plastic and a hollow body made of plastic arranged on the bumper fascia side, the hollow body facing the first on the bumper fascia side opposed to each other with a gap A wall, a second wall on the bumper beam side, and a peripheral wall connecting the peripheral portions of both walls, and the first wall and the second wall are inwardly opposed to each other and fused together. A concave rib is provided.

  According to a second aspect of the present invention, there is provided an automobile impact absorber according to the first aspect, wherein a connecting rib rising in a traveling direction is interposed between the adjacent concave rib and the concave rib. It is what.

  According to a third aspect of the present invention, there is provided the automobile impact absorber according to the second aspect, wherein the concave rib is disposed on a virtual straight line, and a connecting rib is formed on the virtual straight line. It is what.

  According to a fourth aspect of the present invention, there is provided the automobile impact absorber according to the third aspect, wherein the imaginary straight line has an angle within a range of 30 ° to 60 ° with respect to a horizontal line. is there.

  The automobile shock absorber according to claim 5 is the automobile shock absorber according to claim 4, wherein the total length of all the connecting ribs is 20% to 60% with respect to the total length of all virtual lines. It is within the range.

  The automobile impact absorber according to claim 6 is the automobile impact absorber according to any one of claims 2 to 5, wherein the connecting rib is formed only on the first wall.

  According to the present invention, the bumper beam made of metal or plastic is arranged on the vehicle body side, and the hollow body made of plastic is arranged on the bumper fascia side, so that it can be used at the time of collision or contact with other automobiles or other objects. In addition to absorbing a high impact value (20 kN or more), it is possible to obtain an automobile impact absorber excellent in design that can cope with a low impact value (5 kN or less).

  Embodiments of the present invention will be described with reference to the drawings.

  1 is a cutaway perspective view showing a part of a shock absorber of an automobile according to an embodiment of the present invention, FIG. 2 is a front view showing a part of a hollow body, FIG. 3 is a rear view of the same, and FIG. 2 is a cross-sectional view in the direction of arrows AA in FIG. 2, and FIG. 5 is a cross-sectional view in the direction of arrows BB in FIG.

  As shown in FIG. 1 to FIG. 5, an impact absorber 1 for an automobile according to the present embodiment is interposed between a bumper fascia 2 and a vehicle body (not shown) to absorb the impact. And a hollow body 4 arranged on the bumper fascia 2 side. The bumper fascia 2 and the hollow body 4 are made of plastic, and the bumper beam 3 is made of metal or plastic. The thickness of the hollow body 4 is preferably within a range of 30.0 to 100.0 mm from the viewpoint of moldability, and particularly preferably within a range of 30.0 to 70.0 mm. The wall thickness is preferably within the range of 0.3 mm to 6.0 mm, particularly preferably within the range of 0.5 mm to 1.5 mm.

  The hollow body 4 is constituted by a first wall 8 on the bumper fascia 2 side and a second wall 9 on the bumper beam 3 side, which are opposed to each other at an interval, and a peripheral wall 10 that connects the peripheral portions of both walls. The first wall 8 and the second wall 9 have a plurality of pairs of one concave rib 5 and the other concave rib 6 that face each other inwardly, and the one concave rib 5 and the other concave rib 6 that face each other. Are fused to each other in the welded portion 7. That is, the first wall 8 and the second wall 9 are provided with a plurality of concave ribs that are opposed inward and fused to each other.

  And, at least one of the adjacent concave ribs 5 and 5 and the other adjacent adjacent concave ribs 6 and 6 is provided with a concave groove-shaped connecting rib 26 rising in the traveling direction of the automobile. ing.

  In the present embodiment, one concave rib 5 and the other concave rib 6 are arranged on the imaginary straight line g so as to be spaced from each other, and a connecting rib 26 is formed on the imaginary straight line g. As shown in FIG. 2, the imaginary straight line g has an angle α within a range of 30 ° to 60 ° with respect to the horizontal line. Further, the total length of all the connecting ribs 26 is within a range of 20% to 60% with respect to the total length of all virtual straight lines g including the first wall 8, the second wall 9 and the peripheral wall 10. Is set. When the total length of all the connecting ribs 26 is less than 20% of the total length of the imaginary straight line g including the first wall 8, the second wall 9, and the peripheral wall 10, the shock absorber A so-called “bottoming phenomenon” occurs in which the first wall 8 and the second wall 9 come into contact with the impact load from the outside due to inferior rigidity. On the contrary, when it exceeds 60%, the rigidity increases excessively and the buffering property deteriorates.

  The one concave rib 5 and the other concave rib 6 are not limited to the projecting ribs whose projection surfaces are circular as shown in FIGS. 2 and 3, but the projection surfaces may be elliptical. Polygons such as hexagons and octagons may be used.

  Further, the connecting rib 26 is not limited to the concave groove shape shown in FIG. 5, but may be a V groove shape or a plate shape in which two walls are integrated.

  The bumper beam 3 is made of a metal or a plastic. In the case of a metal, a U-shaped plate material such as iron or aluminum is welded to form a structural member such as a cross-sectional box shape. In particular, if a highly rigid metal such as a high-strength steel plate is used, the plate material can be made as thin as possible, thus reducing the weight. The plastic preferably has a high rigidity with a flexural modulus of 4000 MPa or more mixed with carbon fiber or glass fiber. The bumper beam 3 is an elongated shape extending in the width direction of the vehicle body having a cross-sectional box shape or a U-shaped cross section, and has a mounting portion to be attached to the vehicle body.

  The bumper fascia 2 is formed by injection molding or stamping molding of polypropylene or other thermoplastics. The surface of the bumper fascia 2 is painted according to the body of the car, but considering the recyclability at the time of disposal of the car, the use of a resin that is a polymer alloy of other composite resin with polypropylene will result in painting. Resins can be processed simultaneously.

  The hollow body 4 is a resin that can be blow-molded, and is particularly composed of a thermoplastic plastic having a flexural modulus of 800 to 2500 MPa. In consideration of recyclability, polypropylene, polyethylene, polymer alloys or blends based on these, etc. Polyolefin resins are preferred.

  Next, the results of a comparative experiment between one example of an automobile shock absorber according to the present invention and a comparative example will be described below.

  An automobile impact absorber composed of a bumper beam, a bumper fascia and a hollow body similar to those shown in FIGS. 1 to 5 as described below was used.

Bumper beam: Bumper beam with a box-shaped section made of high-tensile steel plate Bumper fascia: Injection molded product made of polypropylene Hollow body: The one shown in FIGS. 1 to 5 was blow-molded. The dimensions were 100 mm × 40 mm × 1200 mm, and the average wall thickness was 1.0 mm. The inner diameter of the concave rib is φ20 mm on the surface side and 10 mm on the fused portion side in both the first wall 8 and the second wall 9. The connecting rib 26 has a concave groove shape, and the ratio of the total length of all the connecting ribs to the total length of all the imaginary straight lines g including the first wall 8, the second wall 9, and the peripheral wall 10 is 25%. It is. As the synthetic resin, polypropylene “AD571” (flexural modulus 1050 MPa) manufactured by Sumitomo Mitsui Chemicals, Inc. was used.

(Comparative example)
In the comparative example, instead of the hollow body of the example, a polyurethane foam is interposed between the bumper fascia and the bumper beam.

Bumper beam: same as the example Bumper fascia: the same as the example Foam: 2.5 kg / cm ³ urethane foam Next, the evaluation is shown in FIG.

  FIG. 6 is a graph obtained as a result of applying the impact absorbers of the above examples and comparative examples to a collision test machine. This collision tester was a collision tester manufactured by Hodogaya Giken Co., Ltd., and collided a columnar collider having a mass of 20 kg, a tip shape of φ70 mm, and a length of 160 mm at a speed of 20 km / hour.

  As is apparent from FIG. 6, the comparative example has a smaller shock absorption than the example. The shock absorption value is the area of the portion surrounded by the curve below the curve and the horizontal axis, but the comparative example has a lower absorption force than the example because the first inclination is gentler. Moreover, since the comparative example uses foamed polyurethane as the foam, the foamed polyurethane is broken apart by collision. For this reason, the broken piece generates a rattling noise in the bumper, and once it receives an impact, it cannot be used again, so it must be replaced. It returns to its original shape and can be used repeatedly.

  Since the impact absorber 1 of the automobile according to the present invention has a hollow body 4 made of plastic interposed between the bumper beam 3 and the bumper fascia 2 on the vehicle body side, the automobile equipped with the impact absorber 1 A high impact value (20 kN or more) when the vehicle collides or comes into contact with another automobile or another object is absorbed by the bumper beam 3. Further, a low impact value (5 kN or less) when the automobile collides or comes into contact is absorbed by the hollow body 4.

1 is a cutaway perspective view showing a part of a shock absorber of an automobile according to an embodiment of the present invention. It is a front view which shows a part of hollow body. It is a rear view same as the above. It is sectional drawing of the AA arrow direction of FIG. It is sectional drawing of the BB arrow direction of FIG. It is a graph which shows the characteristic of the shock absorber of the motor vehicle based on one Example of this invention, and the characteristic of a comparative example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Car shock absorber 2 Bumper fascia 3 Bumper beam 4 Hollow body 5 One concave rib 6 The other concave rib 7 Welded part 8 First wall 9 Second wall 10 Peripheral wall 26 Connecting rib

Claims (6)

A shock absorber for an automobile that is interposed between a bumper fascia and a vehicle body and absorbs an impact received by the bumper fascia,
A bumper beam made of metal or plastic arranged on the vehicle body side, and a hollow body made of plastic arranged on the bumper fascia side,
The hollow body is composed of a first wall on the bumper fascia side and a second wall on the bumper beam side that are opposed to each other at an interval, and a peripheral wall that connects peripheral edges of both walls. A shock absorber for an automobile, wherein the wall is provided with a plurality of concave ribs facing each other inwardly and fused together.   2. The automobile shock absorber according to claim 1, wherein a connecting rib rising in the traveling direction is interposed between the adjacent concave ribs.   The automobile shock absorber according to claim 2, wherein the concave rib is arranged on a virtual straight line, and a connecting rib is formed on the virtual straight line.   4. The shock absorber according to claim 3, wherein the virtual straight line has an angle within a range of 30 [deg.] To 60 [deg.] With respect to the horizontal line.   5. The automobile impact absorber according to claim 4, wherein a total length of all the connecting ribs is within a range of 20% to 60% with respect to a total length of all virtual lines.   6. A shock absorber for an automobile according to claim 2, wherein the connecting rib is formed only on the first wall.

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