Shock absorbing material and vehicle bumper

Abstract

An elongated shock absorbing material having a base section extending lengthwise of the shock absorbing material and two, vertically spaced apart upper and lower ribs extending in the lengthwise direction of the shock absorbing material and also forwardly from one surface of the base section. A cut-away or indented portion extending in the lengthwise direction of the shock absorbing material is formed, for example, in each of the upper and lower ribs at outer side, distal ends thereof or each of edges of top and bottom faces of the base section. The elongated shock absorbing material may be used as a bumper core disposed between a fascia and a reinforcement.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects, features and advantages of the present invention will become apparent from the detailed description of the preferred embodiments of the invention which follows, when considered in the light of the accompanying drawings in which:

FIG. 1( a) is a perspective view diagrammatically illustrating one embodiment of a shock absorbing material according to the present invention;

FIG. 1( b) is a side view of FIG. 1(a);

FIG. 2( a) is a perspective view diagrammatically illustrating another embodiment of a shock absorbing material according to the present invention;

FIG. 2( b) is a side view of FIG. 2(a);

FIG. 3( a) is a side view explanatory of a manner of the buckling of ribs when a shock absorbing material of the present invention is applied with a collision impact;

FIG. 3( b) is a side view explanatory of a manner of the buckling of ribs when a shock absorbing material of the present invention having a different construction is applied with a collision impact;

FIG. 3( c) is a side view explanatory of a manner of the buckling of ribs when a shock absorbing material of Comparative Examples 1 to 3 is applied with a collision impact;

FIG. 4( a) is an enlarged fragmentary view of a shock absorbing material of the present invention, showing an example of a configuration of a cut-away portion;

FIG. 4( b) is an enlarged fragmentary view of a shock absorbing material of the present invention, showing another example of a configuration of a cut-away portion;

FIG. 5 is a side view diagrammatically illustrating a further embodiment of a shock absorbing material according to the present invention;

FIG. 6 shows compression curves of a shock absorbing material of the present invention (curve “a”) and a known shock absorbing material (curve “b”);

FIG. 7( a) is a front elevational view schematically illustrating a compression test method;

FIG. 7( b) is a side view of FIG. 7(a);

FIG. 8 is a fragmentary vertical cross-sectional view schematically illustrating a bumper according to the present invention; and

FIG. 9 is a perspective view diagrammatically illustrating a shock absorbing material in the form of a bumper core according to a further embodiment of the present invention.

Claims

1. An elongated shock absorbing material of a synthetic resin foam, comprising: a base section extending lengthwise of said shock absorbing material and having opposing front and rear surfaces and opposing top and bottom faces joining said front and rear surfaces, andtwo, longitudinally extending, vertically spaced apart upper and lower ribs extending forwardly from said front surface of said base section and terminating in upper and lower free end faces, respectively,said upper and lower ribs having top and bottom outer surfaces, respectively, said top and bottom outer surfaces meeting said top and bottom faces of said base section, respectively, so that said shock absorbing material has a U-shaped cross-section as taken along a plane perpendicular to the longitudinal direction,wherein said upper rib has such a thickness T1 (mm) in the vertical direction and a width H1 in a front-to-rear direction which is perpendicular to the lengthwise direction of said shock absorbing material as to provide a ratio H1/T1 of 3 to 5, while said lower rib has such a thickness T2 (mm) in the vertical direction and a width H2 in the front-to-rear direction as to provide a ratio H2/T2 of 3 to 5, andwherein said shock absorbing material satisfies at least one of the following conditions (A) and (C) and at least one of the following conditions (B) and (D):

2. A shock absorbing material as recited in claim 1, wherein said synthetic resin foam is a foamed molded article of expanded thermoplastic resin beads.

3. A shock absorbing material as recited in claim 2, wherein said expanded thermoplastic resin beads are expanded polyolefin resin beads.

4. A shock absorbing material as recited in claim 2, wherein said foamed molded article has an apparent density of 0.022 to 0.13 g/cm3.

5. A shock absorbing material as recited in claim 1, further comprising an auxiliary rib provided between said upper and lower ribs and extending forwardly from said front surface of said base section.

6. A bumper for attachment to a vehicle, comprising a bumper fascia, a reinforcement, and a shock absorbing material according to claim 1 disposed between said fascia and said reinforcement with the front to rear direction thereof in parallel with a running direction of said vehicle, said fascia being shaped so that spaces are defined between an inside periphery of said fascia and said top and bottom outer surfaces of said upper and lower ribs to receive parts of said upper and lower ribs buckled when the shock absorbing material is subjected to an external impact in the front to rear direction.

7. A bumper as recited in claim 6, wherein the shock absorbing material is disposed between said fascia and said reinforcement with the upper and lower free end faces of said upper and lower ribs facing said fascia.