JP2003343627A - Impact energy absorbing part - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an impact energy absorbing part having a high impact energy absorption capability. <P>SOLUTION: (1) The impact energy absorbing part comprising a molded component of thermoplastic resin foam sheet material, having an impact energy absorbing body using metal material. (2) The thermoplastic resin foam sheet material which is 2-10 times in expansion ratio and 2-10 mm in thickness. (3) A vehicle interior part having an impact energy absorbing part described either in (1) or (2). <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an impact energy absorbing component.

[0002]

2. Description of the Related Art In recent years, in vehicles such as automobiles, there is a tendency for high safety standards to be set for passenger protection measures.
For example, a pillar garnish that covers the interior side of various pillars such as front pillars, center pillars, rear pillars, and center pillar lowers, a door trim that covers doors, a roof side garnish that covers roof side rails, etc. Is required. On the other hand, in order to reduce vehicle manufacturing costs and improve fuel efficiency, vehicle weight reduction is required. For example, Japanese Patent Laid-Open No. 2001-2001
Japanese Patent No. 121561 discloses a vehicle interior component in which a thermoplastic resin rib is attached to a thermoplastic resin foam sheet substrate as an impact energy absorber. However, with the tightening of safety standards in vehicles such as automobiles, it has been desired to develop impact energy absorbing parts having higher impact energy absorbing performance.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide an impact energy absorbing component having high impact energy absorbing performance.

[0004]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies in order to find an impact energy absorbing component having a higher impact energy absorbing performance, and as a result, have formed a molded article made of a thermoplastic resin foam sheet base material. The inventors have found that an impact energy absorbing component provided with an impact energy absorbing body using a metal material has high impact energy absorbing performance, and completed the present invention. That is, the present invention is a molded article made of a thermoplastic resin foam sheet base material,
An impact energy absorbing component comprising a shock energy absorbing body using a metal material.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The impact energy absorbing component of the present invention comprises a molded article made of a thermoplastic resin foam sheet substrate and an impact energy absorber made of a metal material. The thermoplastic resin forming the thermoplastic resin foam sheet substrate can be appropriately selected from a wide range of thermoplastic resins. Examples of the thermoplastic resin include polyethylene resin, polypropylene resin, polystyrene resin, polyethylene terephthalate resin, polyvinyl alcohol resin, vinyl chloride resin, ionomer resin, acrylonitrile / butadiene / styrene resin (A
BS resin) and the like.

Of these, polypropylene resins are preferably used from the viewpoint of heat resistance and the like. As the polypropylene resin, a homopolymer of propylene, a copolymer containing 50 mol% or more of propylene units is preferably used. Examples of the monomer unit other than propylene in the copolymer include ethylene and α-olefin. Examples of α-olefins include α-olefins having 4 to 10 carbon atoms such as 1-butene, 4-methylpentene-1, 1-hexene and 1-octene. The content of the monomer unit other than propylene in the copolymer is preferably 50% by weight or less, and more preferably 30% by weight or less when the monomer unit is an α-olefin. 10% by weight when the monomer unit is ethylene
The following is more preferable.

As the polypropylene-based resin, a polypropylene resin having long-chain branching introduced by low-level electron beam cross-linking (disclosed in Japanese Patent Laid-Open No. 62-121704) or a polypropylene having an ultra-high molecular weight component introduced therein. Resin is also preferably used.

The thermoplastic resin foam sheet base material used in the present invention is made by heating the above-mentioned thermoplastic resin to plasticize it, adding a foaming agent such as carbon dioxide, kneading the mixture, extruding it from a die, foaming it, and collecting it. It can be manufactured by cooling with a machine. It is preferable to use carbon dioxide as a foaming agent from the viewpoint that a foamed sheet having a fine cell diameter can be obtained and the effects on the human body and the environment.
The thermoplastic resin foam sheet base material may be made of one kind of thermoplastic resin or two or more kinds of thermoplastic resins. As the thermoplastic resin foam sheet base material,
A polypropylene resin foam sheet base material is preferably used. The thermoplastic resin foamed sheet base material can be molded into a desired shape by heating it in an oven or the like to plasticize it and shaping it into a desired shape by a vacuum forming method in which female vacuum drawing is performed.

The expansion ratio of the thermoplastic resin foam sheet substrate is not particularly limited, but considering the balance between the weight and strength of the product, the expansion ratio is preferably 2 to 10 times, and the expansion ratio is 2 to. It is more preferably 5 times. The foam cell diameter of the thermoplastic resin foam sheet base material is 0.
The thickness is preferably 1 μm to 2 mm, and more preferably 10 to 500 μm from the viewpoint of the strength and processability of the foamed sheet. The thickness of the thermoplastic resin foamed sheet base material is preferably 0.5 to 100 mm, and is 2 to 10 from the viewpoint of the strength of the sheet, ease of handling, and the like.
More preferably, it is mm.

The impact energy absorber using the metallic material used in the present invention is not particularly limited as long as the metallic material is used, and can be appropriately selected.
From the viewpoint of impact energy absorption performance, it is preferable that the impact energy absorber is a hybrid pipe composed of a core material of a metal foil and sheets of materials other than metal that are laminated on the front and back surfaces of the core material. Examples of the core material of the metal foil include core materials made of metal foil of iron, hard aluminum, stainless steel, or magnesium alloy, and from the viewpoint of impact energy absorption performance and weight reduction, the core material made of hard aluminum is preferable. As the material other than the metal laminated on the front and back sides of the core material, paper such as kraft paper is preferable in terms of impact energy absorption performance and price. The impact energy absorber has a continuous wavy shape in the axial direction to form a concave portion 22 and a convex portion 24. The concave and convex portions 22 and 24 are formed in a spiral shape as shown in FIG. Is preferable from the viewpoint of impact energy absorption performance. In addition, the impact energy absorber is preferably a flexible pipe having a substantially rectangular cross section, from the viewpoint of impact energy absorption performance and ease of attachment to the thermoplastic resin foam sheet base material. The quadrilateral shape means either a square shape or a rectangular shape.

In the impact energy absorbing component of the present invention, the position of the impact energy absorbing body made of a metal material, which is provided in the molded article made of the thermoplastic resin foam sheet substrate, is not particularly limited, but the molded article is The back surface is preferable in terms of appearance. Particularly when used as a vehicle interior component, a portion where the head, chest, abdomen and the like of an occupant collide upon impact is preferable. Also, the number of impact energy absorbers using a metal material is not particularly limited. The impact energy absorber can be provided on the thermoplastic resin foam sheet base material by a method such as fusion bonding, laminating with an adhesive or a double-sided tape, and attaching with a screw.

In the impact energy absorbing component of the present invention, the thermoplastic resin foam sheet base material may have a surface material on its surface. Such a skin material is disposed on the surface of the thermoplastic resin foam sheet base material, and functions to decorate, reinforce, protect, and the like. Examples of the skin material include woven cloth, non-woven cloth, knitted cloth, Sheet, film, foam,
Examples include reticulate materials. The material constituting the skin material is not particularly limited, but examples thereof include thermoplastic resins such as polyolefin resins, polyvinyl chloride resins, polystyrene resins, thermosetting resins such as polyurethane resins, and cis-1,4. -Rubber such as polybutadiene and ethylene / propylene copolymer, thermoplastic elastomer, cotton,
Examples include natural fibers such as cellulosic fibers such as hemp and bamboo. Further, paper or metal foil may be used as the skin material. Further, the skin material may be provided with an uneven pattern such as grain, printing or dyeing. The skin material may have a single-layer structure or a multi-layer structure composed of two or more layers. The skin material can be placed on the surface of the thermoplastic resin foam sheet base material by a method such as heating and fusion bonding, or laminating with an adhesive or solvent.

Since the impact energy absorbing component of the present invention thus obtained has excellent impact energy absorbing performance, the front pillar, the center pillar,
It is preferably used as a vehicle interior component such as a pillar garnish that covers the interior side of various pillars such as a rear pillar and a center pillar lower, a door trim that covers a door, and a roof side garnish that covers a roof side rail.

[0014]

EXAMPLES The present invention will be described below based on examples, but it goes without saying that the present invention is not limited to the examples. The impact test was carried out according to the following procedure to evaluate the impact energy absorption performance.

[Impact test] FMVSS201 (Federal Motor V)
The impact test was carried out by a method based on Vehicle Standard No. 201). A veneer plate was attached to a fixed base made of a rigid body and perpendicular to the striking direction, and the impact energy absorbing component was fixed. Impact tester (Manufactured by: Hodogaya Giken Co., Ltd.)
Using the model: HG-12132), the dummy doll's head (FWH: Vector Co., Ltd.) is made to fly freely at a speed of 24 km / hour by aerodynamic force.
It collided with the impact energy absorbing component. Then, the synthetic acceleration calculated from the triaxial acceleration sensor value in the head of the dummy was calculated, and the HIC (d) value was calculated from that value, which was used as a measure of the impact energy absorption performance. Regarding the calculation method of the HIC (d) value, the calculation method described in the above FMVSS201 was used. The smaller the value, the lesser the damage to the dummy doll head is.

Example 1 As a thermoplastic resin foam sheet, a polypropylene foam sheet (manufactured by Sumika Plus Tech Co., Ltd., trade name: Sumiceller foam PP sheet 3030, expansion ratio = 3 times, thickness = 3 mm) and olefin series A foamed sheet obtained by laminating a thermoplastic elastomer sheet (manufactured by Sanvic Co., Ltd., thickness = 1.2 mm) with hot air was used. The foamed sheet is heated in the oven to a temperature in the range of 145 ° C. to 150 ° C., and vacuum vacuum forming is performed while assisting with a plug to shape the laminated foamed sheet into a door trim shape and to form a grain pattern on the surface of the vacuum forming female mold. It was transferred to an olefinic thermoplastic elastomer sheet. After vacuum suction and shaping, the product was cooled for 30 seconds to obtain a door trim-shaped molded product. The obtained door trim shaped molded product is placed in a pair of male and female molds, the temperature of which is adjusted to 30 ° C., the molds are clamped, the door trim molded product is sandwiched between the male and female molds, and the resin temperature is 230 ° C. An injection machine cylinder The rib-molding resin melt-kneaded inside was supplied to the ribs provided on the male die product surface and the recesses for clip seat molding through a molten resin supply passage provided in the male die, and filling and shaping were performed. As a thermoplastic resin, Sumitomo Noblen AX568 (Polypropylene manufactured by Sumitomo Chemical Co., Ltd., melt index = 65 g
/ 10 minutes) and Smithtran PG003 were blended to 80/20 and used. After cooling for 20 seconds in this state,
The male and female molds were opened and the molded product was released from the mold, and a foam sheet made of a thermoplastic resin was obtained in which ribs and clip seats were integrally molded on the back surface of the door trim molded product.

As the impact energy absorber, O-EA manufactured by Otsuka Co., Ltd. was used. The structure is shown in FIG. The impact energy absorber is a quadrangle with a side of 30 mm, and the surface is kraft paper or hard aluminum foil (3
Layer) and kraft paper have a laminated structure of 5 layers. The thickness of each layer is 0.2 mm for kraft paper, 0.09 mm for each hard aluminum foil, and 0.2 mm for kraft paper. These layer materials are wavy in the axial direction, and are formed with concave portions and convex portions. An impact energy absorber having a length of 20 cm in the axial direction was fused to a predetermined portion of a thermoplastic resin foam sheet to obtain an impact energy absorbing component.

An impact test was conducted by setting the impact point of the dummy doll head at the center of the impact energy absorber welded to the thermoplastic resin foam sheet. The relationship between the obtained displacement and the resultant acceleration is shown in FIG. 3, and the results are shown in Table 1.

Comparative Example 1 An impact test was conducted in the same manner as in Example 1 except that the impact energy absorber was not used. The relationship between the obtained displacement and the resultant acceleration is shown in FIG. 3, and the results are shown in Table 1.

[0020]

[Table 1]

[0021]

According to the present invention, it is possible to provide an impact energy absorbing component having high impact energy absorbing performance.

[Brief description of drawings]

FIG. 1 is a drawing showing the shape of an impact energy absorber used in Examples.

FIG. 2 is a conceptual diagram showing an outline of the entire configuration of a collision test.

FIG. 3 is a drawing showing displacement-load curves of collision tests of Example 1 and Comparative Example 1.

Claims (5)

[Claims] 1. An impact energy absorbing component comprising a molded article made of a thermoplastic resin foam sheet base material and an impact energy absorber made of a metal material. 2. The impact energy absorbing component according to claim 1, wherein the thermoplastic resin foam sheet base material is a base material having an expansion ratio of 2 to 10 and a thickness of 2 to 10 mm. 3. The impact energy absorbing component according to claim 1, wherein the thermoplastic resin foam sheet base material is a polypropylene resin foam sheet base material. 4. An impact energy absorber using a metal material is a hybrid pipe comprising a core material of a metal foil and sheets of a material other than metal which are respectively laminated on the front and back of the core material. The impact energy absorbing component according to any one of 3 above. 5. A vehicle interior component comprising the impact energy absorbing component according to any one of claims 1 to 4.