JPH10169686A - Resin-made shock absorbing member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin-made shock absorbing member formed in small size to lighten weight and display high energy absorbing power. SOLUTION: A plurality of molded units, molded by a resin of 500 to 6000kg/cm<2> bending elastic modulus to have a crest part and a trough part to display outward appearance of corrugated board shape, are layered, in a stress/compressibility curve at compression time in a height direction, a relation yield strength >=1000T/m<2> , energy absorbing amount per unit volume >=50T.m/m<3> is satisfied.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin shock-absorbing member which can be applied to a portion requiring shock absorption or mitigation, for example, a road or quay side wall, a building floor or wall, and a vehicle shock absorbing portion. .

[0002]

2. Description of the Related Art Conventionally, as a shock absorbing means, a metal spring, a friction type shock absorber, a hydraulic type shock absorber, a rubber molded body, and the like have been used, and when any of these is used in combination. is there. Although the metal spring has excellent shock absorbing performance, it hardly absorbs collision energy. Further, the friction type shock absorber and the hydraulic type shock absorber generally have complicated structures, and the spring constant has a very large deformation speed dependency, and has no restoring property.

[0003] A rubber molded article has a characteristic of good resilience, but since the elastic modulus of the material is low, the amount of the material used must be increased in order to secure a satisfactory amount of shock absorption. However, there is a disadvantage that the weight of the member increases and the size of the member increases.

Further, there has been disclosed a technique for manufacturing a resin molded article characterized in that a hollow molded article using a thermoplastic elastomer as a shock absorber made of a resin molded article is axially compressed to impart a permanent set. Yes
No. 79), however, there is a problem that the resin molded article according to this technique has excellent cushioning performance, but has poor ability to absorb collision energy.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above-mentioned problems of the conventional shock absorbing means, and has as its object a small and light-weight and simple structure which can be compared with the reaction force. Therefore, it is intended to provide a resin shock absorbing member having a large energy absorption amount and excellent energy absorbing ability.

[0006]

That is, according to the present invention, a resin molded body having a plurality of surfaces which become peaks and valleys with respect to the direction of impact is formed in a direction in which ridges and valleys have the same direction. A shock absorbing member having a laminated structure of a structure in which a plurality of layers are stacked so as to absorb impact energy by buckling deformation of the laminated structure and elastic properties of the resin of the structure; and A resin shock absorbing member characterized in that a reaction force / compression rate curve during compression satisfies the following (a) and (b). (A) The yield strength is 1000 T / m ² or more. (B) Compressed energy absorption per unit volume is 50T
m / m ³ or more. Further, the resin molded body is a corrugated plate having a trapezoidal peak and a valley in a height direction, and a strip having a predetermined width is connected in a plurality of rows in a planar direction with peaks and valleys being staggered. The bending elastic modulus is 5 in the gap between the overlapping portion of the resin shock absorbing member and the laminated structure, which is a molded body having the structure described above.
The above-mentioned resin shock absorbing member having a resin spacer of 100 to 6000 kg / cm ² inserted therein. In the resin shock absorbing member, the displacement amount of the reaction force generated in the entire compression region during the compression process is always positive, so that the shock absorbing effect can be further improved.

BEST MODE FOR CARRYING OUT THE INVENTION

In the present invention, the resin molded article is connected in a plurality of rows so that peaks or valleys are in the same direction when viewed from the direction of impact, and the slope intermediate portions, which are the contact portions, are connected. May be integrated.

[0008] The resin molded article may have a belt-shaped reinforcing frame.

The resin forming the resin structure of the present invention comprises:
A member having a laminated structure formed of a resin having a flexural modulus of 500 to 6000 kg / cm ² and a flexural modulus of 5
As a resin of 00 to 5000 kg / cm ² , thermoplastic polyester elastomer, polyolefin elastomer,
Polyurethane elastomer, polyamide elastomer,
Alternatively, a blend thereof, a curable resin such as cast polyurethane, and the like are exemplified. Of these, particularly preferred are thermoplastic polyester elastomers and polyolefin elastomers having excellent weather resistance and water resistance, but the types thereof are not particularly limited as long as the flexural modulus falls within the above specified range.

It is preferable to insert a resin spacer into the gap between the overlapping portions in the laminated structure of the present invention. The spacer has a flexural modulus of 500 to 600.
By using a resin of 0 kg / cm ² and changing the shape and quantity of the spacer to be inserted, the rise of the reaction force of the resin shock absorbing member can be accelerated and the yield reaction force can be increased as necessary. Therefore, it is possible to construct a small and lightweight resin shock absorbing member, and it is possible to prevent breakage at high compression.

Further, as a material of the spacer, a resin having a rebound resilience (JIS K6301) of 50% or more and a compression set (JIS K6301 at 70 ° C.) of 60% or less is preferable. These resins include thermoplastic polyester elastomers, polyamide elastomers, polyurethane elastomers, polyolefin elastomers, silicone elastomers and the like.

Means for connecting the resin shock absorbing member and the resin molded body include a method of applying an adhesive to the connecting portion and fixing the same, a method of fixing the connecting portion by heat fusion, a metal rivet and a plastic. A method of fixing using rivets made of resin, a method of fixing using bolts and nuts, a connecting hole and a fitting projection, a concave and convex for self-snap are provided in the connecting portion in advance, and a resin shock absorbing member and a resin There are a method of combining the shock absorbing pieces with one touch in the laminating direction, and a method of fixing using a belt.

Further, a shock absorbing block can be constructed in the same manner as described above by using a resin shock absorbing member having no belt-shaped reinforcing frame.

When the resin shock absorbing member of the present invention is put into practical use, the number of installation members can be arbitrarily set according to the degree of shock absorbing force required according to the application place. In order to achieve the above, the yield strength confirmed by a reaction force-compression rate curve when the resin shock absorbing member is compressed in the height direction is not less than 1000 T / m ² and per unit volume of the shock absorbing member. 5 compression energy absorption
It is necessary to be 0T · m / m ³ or more.

Here, a reaction force-compression ratio curve (hereinafter referred to as SS)
Curve) is a graph showing the correlation between the reaction force (compression force / pressure receiving area) and the compression ratio when the resin shock absorbing member is compressed in the direction of impact, for example. In, the SS curve rises sharply in proportion to the compression ratio, and then gradually becomes gentle (flat portion) to reach the yield point showing the maximum reaction force locally, where the resin shock absorption Although the member yields, the displacement of the reaction force generated in the entire compression region during the compression process is always positive, so that the impact relaxation effect can be further improved. Thereafter, when the compression is further continued, the SS curve rapidly rises again due to the decrease in the gap, and the reaction force suddenly rises with a slight increase in the compression ratio.

The yield strength of the SS curve of the present invention means the maximum reaction force at the flat portion after the first rise, and the compression energy absorption per unit volume is defined as a compression ratio of 80. % Means a value obtained by dividing the amount of compressed energy absorption indicated by the area surrounded by the SS curve (shaded region in FIG. 2) by the volume of the shock absorbing member.

The yield strength of the present invention is determined by the impact absorber S
Although it does not always match the maximum reaction force value in the entire -S curve, it is a value close to the maximum reaction force received by the impact object when the shock absorbing member receives the impact force, and is considered as a guideline of the maximum reaction force value. When the yield strength is insufficient, the function of the impact energy absorber is not substantially exerted. On the other hand, when the yield strength is too large, the reaction force generated at the time of impact becomes large and the impact cannot be satisfactorily reduced. In order to efficiently absorb impact energy, it is effective to make the first rise of the SS curve as sharp as possible and to minimize the decrease in the reaction force after passing the yield point.

As a result of various studies on the physical properties required of the resin shock absorbing member according to the present invention from such a viewpoint, it is necessary to sufficiently reduce the impact force without giving an excessive reaction force to the resin impact absorbing member. The yield strength of the absorbent
It is necessary that the absorption of compression energy be not less than 00 T / m ² and the amount of absorbed compression energy be not less than 50 T · m / m ³ per unit volume of the shock absorbing member. The resin shock absorbing member of the present invention sufficiently satisfies such required characteristics. Things.

By the way, in a conventionally known shock absorber such as a rubber molded product, the rise of the SS curve in FIG. 3 is slow. The amount of use must be increased, the weight of the member increases, and the size must be increased.

On the other hand, a hollow molded article using a thermoplastic elastomer disclosed in Japanese Patent Publication No. 61-12779 is axially compressed so that a resin molded article to which permanent deformation is imparted does not substantially undergo buckling deformation. Since it is a molded product, it exhibits an SS curve similar to that of a rubber molded product, and has poor ability to absorb collision energy.

However, according to the shock absorber of the present invention in which the bending elastic modulus of the resin is specified and its shape and structure are determined as described above, as shown in the schematic diagram of FIG. Not only steep, but also a moderate yield strength, and even if the compression ratio is further changed, it shows a substantially constant reaction force for a while, and then shows a final sudden rise, resulting in 80% compression. Has a very high compression energy absorption amount of 50 T · m / m ³ or more per unit volume.

As described above, the impact absorbing member of the present invention provides a dash pot and a spring-like energy absorbing behavior by a combination of the viscoelastic properties of the resin having an appropriate bending elasticity and its shape as described above. Can be absorbed very efficiently.

As a method for producing the resin molded article and the resin shock absorbing member according to the present invention, any method such as injection molding, extrusion molding or press molding can be adopted. Further, the resin shock absorbing member of the present invention can adopt a normal mounting method, for example, a method of mounting to another structure through a hole provided in a flat plate portion constituting the shock absorbing member. Is not limited at all.

The preferred types of the resin used in the present invention are as described above. These resins may be added to various stabilizers such as, for example, a thermal antioxidant and an ultraviolet absorber according to the application or purpose. , Fillers such as dyes and carbon black, talc and glass beads, fibrous reinforcing agents such as metal fibers, glass fibers and carbon fibers, antistatic agents, plasticizers, flame retardants, foaming agents, release agents, etc. It is also possible to modify by adding additives.

[0025]

The present invention is configured as described above.
By using a resin with a specified flexural modulus and by specifying its shape and structure, it has excellent shock absorption properties due to the elastic properties of the resin and the buckling deformation of the molded product, and is compact and lightweight. In spite of this, it has become possible to provide an impact absorbing member exhibiting high impact energy absorbing ability. The shock absorbing member can be widely applied to, for example, a side wall of a road or a quay, a floor or a wall of a building, and a shock absorbing portion of a vehicle by utilizing its excellent characteristics.

[0026]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. However, the present invention is not limited to the following Examples and is not limited to the following Examples. Any of the modifications is included in the technical scope of the present invention.

Example 1 Using a polyester elastomer "Perprene P-150B" manufactured by Toyobo Co., Ltd., a cross-sectional shape shown in FIG. 1 was trapezoidal and had a cell structure consisting of six sides as viewed from the front. Body block (20cm × 5
0 cm × 4 cm and an average thickness of 2 mm) were obtained by the injection molding method, and five molded bodies were obtained. The upper surface (peak) of the cell structure became a pressure receiving surface and the lower surface (valley) became a fixed surface. A resin shock absorbing member was obtained by stacking the pressure receiving surfaces so as to be in the same direction to form a five-layer laminate (height: 10 cm).
Table 1 shows the evaluation results.

Example 2 A five-layer laminate was obtained in the same manner as in Example 1. A cylindrical (8 mm × 10 mm, 1.4 mm thick) spacer was inserted into the gap between the overlapped portions of this laminate of the same material as above to obtain the resin shock absorbing member of the present invention. Table 1 shows the evaluation results.

Example 3 A resin shock absorbing member of the present invention was obtained in the same manner as in Example 2 except that the resin was changed to Perprene 120B. Table 1 shows the evaluation results.

Example 4 A resin shock absorbing member of the present invention was obtained in the same manner as in Example 2, except that the resin was changed to Perprene 280B. Table 1 shows the evaluation results. [Comparative Example] A resin shock absorbing block having five layers of resin shock absorbing blocks so that the pressure receiving surface (upper surface) and the fixed surface (lower surface) of the cell structure of the resin shock absorbing block obtained in Example 1 overlap each other. A shock absorbing member was obtained (height 20 cm). Table 1 shows the evaluation results.

[Evaluation Method] Flexural modulus of resin: commonly used ASTM-D
790. Impact force receiving surface area: Refers to the flat plate contact area at the end of the large deformable portion. Yield strength: When compressed at a constant speed of 50 mm / min, the reaction force-compression curve rises almost in proportion to the compression ratio at the beginning of compression, and then gradually becomes gentle (flat portion) to become the maximum reaction force. Means the strength per unit area of the impact receiving surface. Compressive energy absorption: The area surrounded by the reaction force-compression curve up to a maximum compression ratio of 80% in a curve in which the vertical axis represents the reaction force and the horizontal axis represents the compression amount. Compression energy absorption per unit volume: A value obtained by dividing the compression energy absorption by the volume of the shock absorber.

[0032]

[Table 1]

[Brief description of the drawings]

FIG. 1 is a perspective view showing an external appearance of an example of a resin molded block which is a constituent member of a resin shock absorbing member.

FIG. 2 is an explanatory diagram showing a reaction force-compression ratio curve of the shock absorbing member according to the present invention.

FIG. 3 is an explanatory diagram showing a reaction force compression ratio curve of a conventional shock absorber.

FIG. 4 is an explanatory diagram showing a reaction force-compression ratio curve of the shock absorbing member according to the present invention.

Continued on the front page (72) Inventor Yujiro Matsuyama 2-1-1 Katata, Otsu City, Shiga Prefecture Inside Toyobo Co., Ltd. Research Laboratory

Claims (3)

[Claims] 1. A plurality of resin molded bodies each having a plurality of surfaces that become peaks and valleys with respect to the direction of impact are stacked so that the ridges and valleys have the same direction. A shock absorbing member having a laminated structure having a laminated structure, wherein the buckling deformation of the laminated structure and the elastic properties of the resin of the structure absorb the impact energy, and a reaction force / compression rate curve at the time of compression Characterized in that they satisfy the following requirements (a) and (b): (A) The yield strength is 1000 T / m ² or more. (B) Compressed energy absorption per unit volume is 50T
m / m ³ or more. 2. A resin molded article is a corrugated sheet having a trapezoidal peak and a valley in a height direction, and a strip having a predetermined width is formed in a planar direction with peaks and valleys being staggered. The resin-made shock absorbing member according to claim 1, which is a molded body having a structure in which a plurality of rows are connected. 3. The resin shock absorbing member according to claim 1, wherein a resin spacer having a bending elastic modulus of 500 to 6000 kg / cm ² is inserted into a gap between the overlapping portions of the laminated structure.