JPH10169687A - Resinmade shock absorber and shock absorbing method using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance energy absorbing capacity of a resinmade shock absorber while aiming at downsizing and weight reduction thereof by forming the shock absorber in a honeycomb configuration by means of resin having a specific bending elastic modulus and securing the yield strength and a compression energy absorptive quantity owing to buckling deformation above specific values. SOLUTION: In an shock absorber integratedly molded with resin of its bending elastic modulus in a range from 500 to 5000kg/cm<2> , the cavity part 2 of a hexagonal shape sectional surface surrounded by a bulkhead 1 is pointed in same direction to be formed continuously and in plural layer-like. This cavity part 2 is formed in such a way as absorbing shock energy by placing the bulkhead 1 and the cavity part 2 in buckling deformation against longitudinal shock force applied to its sectional surface. It is necessary that the yield strength confirmed by a reaction-contraction rate curve is 100T/m<2> or more when this shock absorber is contracted in an arrow direction, and a compression energy absorptive quantity is 50T.m/m<3> or more. Accordingly, owing to the elastic characteristic of resin and buckling deformation of a molded body, excellent shock absorbing characteristic can be secured and downsizing and weight reduction can be planned.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a resin shock absorber which can be applied to a part which needs to absorb or mitigate a shock, for example, a side wall of a road or a quay, a floor or a wall of a building, and a shock buffer of a vehicle. The present invention relates to a method for absorbing and mitigating impact.

[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.
In addition, the above-mentioned friction type shock absorber and hydraulic type shock absorber generally have a complicated structure, have a very large dependency on a deformation speed in a spring constant, and have problems such as lack of restorability.

[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.

As a shock absorbing means using a resin molded article, the present inventors have made a resin molded article having a cushioning property in which a plurality of arch-shaped, dome-shaped or honeycomb-shaped compressed deformation portions are erected on a perforated or non-perforated flat plate. We have proposed a shock absorber consisting of a body. However, the shock absorber has a feature of exhibiting a uniform cushioning performance over a wide area such as a road side wall or a floor of a building, but is hardly applicable to a case where the shock absorber must be installed in a very limited space. There was a problem.

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 permanent strain. Yes (Japanese Patent Publication No. 61-127)
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.

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 has a large energy absorption compared with the reaction force. It is intended to provide a resin shock absorber excellent in energy absorption, characterized in that it has rust prevention, water resistance, weather resistance and can be used maintenance-free regardless of whether it is on the ground or in the sea. is there.

[0007]

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. Accordingly, it is intended to provide a resin shock absorber having a large energy absorption amount and excellent energy absorption ability.

[0008]

That is, according to the present invention, a cavity surrounded by a partition wall formed of a resin having a flexural modulus of 500 to 5000 kg / cm ² is continuously and multilayered in the same direction. A shock absorber having a formed and structured cross-sectional shape and having a honeycomb-like shape, wherein a cavity partition wall of the shock absorber is buckled and deformed, and a reaction force and a reaction force when the shock absorber is compressed in the longitudinal direction. A resin shock absorber characterized in that a compression ratio curve satisfies the following (a) and (b). (A) The yield strength is 100 T / m ² or more. (B) The compression energy absorption is 50 T · m / m ³ or more. When a step is provided at a part of the end of the partition wall, the reaction force generated with respect to the reaction force applied to the honeycomb-shaped cross section can be made uniform, and the impact relaxation effect can be further improved. Further, the resin shock absorber of the present invention must be used so as to absorb impact energy by compressive deformation in the length direction (buckling deformation of partition walls and hollow portions).

BEST MODE FOR CARRYING OUT THE INVENTION

The resin forming the resin shock absorber of the present invention is a resin having a flexural modulus of 500 to 5000 kg / cm ^{2, and} a thermoplastic resin having a flexural modulus of 500 to 5000 kg / cm ² is thermoplastic. Examples thereof include a polyester elastomer, a polyolefin elastomer, a polyurethane elastomer, a polyamide elastomer, a blend thereof, and a curable resin such as cast polyurethane. 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.

Incidentally, the flexural modulus is 500 kg / cm ^2.
With less than the resin, the spring constant of the obtained shock absorber is insufficient, so that the thickness of the components must be increased in order to have satisfactory energy absorption performance,
Since the shock absorber becomes large and heavy, it does not conform to the gist of the present invention.

On the other hand, the flexural modulus is 5000 kg / cm ²
If it exceeds, the obtained shock absorber becomes too rigid and lacks flexibility, and when subjected to compressive force, it becomes easy to burst at the time of buckling deformation of the cavity partition wall. I can't do it.

On the other hand, the flexural modulus is 500 to 500.
When a resin of 0 kg / cm ² is used, the rise of the reaction force of the shock absorber can be accelerated and the yield reaction force can be increased as required, so that the resin can be used as in a conventionally used rubber molded body. Small size without extremely thick wall
It is possible to use a lightweight shock absorber, and it is not easy to break when compressed. A preferred range of flexural modulus, 500~3500kg / cm ^2, more preferably 900~2000kg / cm ^2.

The shock absorber of the present invention is formed so as to be able to absorb shock as a whole by molding into a shape and a structure as described in detail below using a resin satisfying the above-mentioned requirements of the flexural modulus. I do. That is, FIG. 1 illustrates an example of the structure of the shock absorber according to the present invention, which is a resin shock absorber integrally formed of a resin having a flexural modulus of 500 to 5000 kg / cm ² and surrounded by a partition wall 1. The hollow portion 2 having a hexagonal cross section is formed continuously and in multiple layers in the same direction.

In a shock absorber having a honeycomb-shaped cross section having a structure as shown in the drawing, a cavity 2 surrounded by a partition 1 is provided with a partition wall and a cavity against a longitudinal impact force applied to the cross section. The impact energy is absorbed by the buckling deformation of the portion, and the cross-sectional shape and dimensions of the resin shock absorber are set as necessary, and the shape is not limited at all, and various shapes and structures are provided. Can be molded into

Further, when the shock absorber of the present invention is put into practical use, the number of installations can be arbitrarily set according to the degree of shock absorbing power required according to the application place, but the object of the present invention is achieved. In order to achieve this, the yield strength confirmed by the reaction force-compression ratio curve when this shock absorber is compressed in the direction of the arrow (length direction) in FIG. 1 is 100 T / m ² or more, and the compression energy absorption amount is 50 T - it is necessary that the m / m ² or more.

Here, a reaction force-compression ratio curve (hereinafter referred to as SS)
Is a graph showing the correlation between the reaction force (compression force / pressure receiving area) and the compression ratio when the resin shock absorber is compressed in the direction of impact, for example, and the initial stage of compression. In the above, the SS curve rises sharply in proportion to the compression ratio, and then gradually becomes gentle and gradually reaches the yield point where the maximum reaction force is locally exhibited. After yielding and buckling of the cavity, the reaction force remains at a substantially constant level (independent of the increase in the compressibility) until the SS curve rises sharply again due to the decrease in the air gap. Flat part) is maintained. As shown in FIG. 1, when the partition wall of the resin shock absorber is formed into a shape having a step by partially cutting the partition wall, the yield reaction force is reduced and the flat portion reaction force is reduced. This is preferable because it can be adjusted to a substantially constant level, and the reaction force generated with respect to the reaction force applied to the honeycomb-shaped surface can be made uniform.

The yield strength of the SS curve of the present invention means a reaction force value which shows the maximum in the flat portion after the first rise, and the compression energy absorption means the compression ratio of 8
It means a value obtained by dividing the absorbed energy indicated by the area (shaded region in FIG. 2) surrounded by the SS curve up to 0% by the volume of the shock absorber.

In the present invention, the yield strength is determined by the impact absorber S
-The value does not always match the maximum reaction force value in the entire area of the S curve, but is a value close to the maximum reaction force received by the impact object when the shock absorber receives the impact force, and is considered as a guide 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.

From these viewpoints, various studies have been made on the physical properties required of the resin shock absorber according to the present invention. As a result, it is necessary to reduce the impact force sufficiently without giving an excessive reaction force to the impact force. The yield strength of the absorber is 100T /
m ² or more and the compression energy absorption amount must be 50 T · m / m ³ or more, and preferably, the yield strength is 150 T / m ²
As described above, the compression energy absorption is 200 T · m / m ³ .
According to the resin shock absorber of the present invention, such required characteristics are sufficiently satisfied.

Incidentally, in a conventionally known shock absorber such as a rubber molded product, since the rise of the SS curve is slow as shown in FIG. 3, it is necessary to secure a satisfactory shock absorption amount. You have to use a lot of materials,
The weight of the member is increased, and the size must be increased.

On the other hand, the resin shock absorber of the present invention, in which the bending elastic modulus of the resin is specified and the shape and structure of the resin are determined as described above, as shown in the schematic diagram of FIG. After the initial rise is not only steep but also shows a moderate yield strength, it shows a substantially constant reaction force for a while even if the compression ratio is further changed, and then shows the final sudden rise, resulting in 50T It comes to have a very high compression energy absorption of · m / m ² or more.

The shock absorber according to the present invention provides a dash pot and a spring-like energy absorbing behavior by combining the viscoelastic properties of the resin having an appropriate bending elasticity and its shape, as described above, to provide an impact energy. Can be absorbed very efficiently, and damage to the collision object due to impact can be suppressed to a minimum.

As a method for producing the resin shock absorber according to the present invention, any method such as injection molding, extrusion molding or press molding can be employed. In addition, the resin shock absorber of the present invention can adopt a normal mounting method, for example, a method of mounting the shock absorber on another structure through a hole provided in a flat plate portion forming the shock absorber. 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.
Use a resin with a specified flexural modulus, and
By specifying the structure, we provide a shock absorber that has excellent shock absorption characteristics due to the elastic properties of the resin and the buckling deformation of the molded body, and that has high impact energy absorption capacity while being compact and lightweight. I got it. The shock absorber 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 A polyester elastomer "Perprene P-90B" manufactured by Toyobo Co., Ltd. was used.
A shock absorber having a hexagonal cross section shown in FIG. 1 (thickness t = 5 m)
m, side length 1 = 10 mm, thickness H = 100 mm) were injection molded (overall dimensions; W = 500 mm × D = 200 m)
m). Table 1 shows the results of evaluation by compressing the shock absorber in the vertical direction (length direction).

Example 2 Using a polyester elastomer "Perprene P-70B" manufactured by Toyobo Co., Ltd.
A shock absorber having a hexagonal cross section shown in FIG. 1 (thickness t = 5 m)
m, side length 1 = 10 mm, thickness H = 100 mm) were injection molded (overall dimensions; W = 500 mm × D = 200 m)
m). Table 1 shows the results of evaluation by compressing the shock absorber in the vertical direction (length direction).

[Comparative Example 1] A shock absorber 21 cm x 21 cm x height 3 using a polyester elastomer "Perprene P-280B" manufactured by Toyobo Co., Ltd. and having eight large arch-shaped deformable portions. 3 cm was injection molded.
The absorber was able to compress substantially up to 80% vertically. The shock absorber 101c is assembled by joining the absorber in vertical and horizontal directions and in the height direction with resin rivets.
m × 101 cm × 99 cm were produced. Table 1 shows the evaluation results obtained by compressing the shock absorber in the vertical direction.

[Evaluation method] Flexural modulus of resin: commonly used ASTM-D
790. Yield strength: When compressed at a constant speed of 50 mm / min, the reaction-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. Compressed energy absorption: refers to the amount of energy absorbed per unit volume of the shock absorber when compressed to a compression ratio of 80% in the reaction force-compression ratio curve.

[0031]

[Table 1]

COMPARATIVE EXAMPLE 2 A commercial rubber mass having a hardness of 63 A was cut to obtain an impact absorber having the same shape as in Example 1. The weight of this shock absorber was 4.5 kg, the yield strength was 30 T / m ² , and the amount of compressed energy absorbed per unit volume was 45 T · m / m ³ , but the reaction force increased as the compression ratio increased. Because of the rapid rise, the effect of suppressing damage to the collision object is low.

As is clear from the above, the shock absorber of the present invention can absorb a larger impact energy than the conventional shock absorber. Therefore, the effect of suppressing damage to the collision object is great. Moreover, it can be used in the air and in the sea without any trouble, and has excellent rust prevention, water resistance and weather resistance, and is maintenance-free.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an example of a shape of a shock absorber according to the present invention.

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

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Partition wall 2 Cavity part 3 Step part

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[Procedure amendment]

[Submission date] September 16, 1997

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0027

[Correction method] Change

[Correction contents]

Example 1 A polyester elastomer "Perprene P-90B" manufactured by Toyobo Co., Ltd. was used.
A shock absorber having a hexagonal cross section shown in FIG. 1 (wall thickness t = 4.3)
mm, side length 1 = 25 mm, thickness H = 100 mm) were injection molded (overall dimensions; W = 500 mm × D = 200).
mm). Table 1 shows the results of evaluation by compressing the shock absorber in the vertical direction (length direction).

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0028

[Correction method] Change

[Correction contents]

Example 2 Using a polyester elastomer "Perprene P-70B" manufactured by Toyobo Co., Ltd.
A shock absorber having a hexagonal cross section shown in FIG. 1 (wall thickness t = 4.3)
mm, side length 1 = 25 mm, thickness H = 100 mm) were injection molded (overall dimensions; W = 500 mm × D = 200).
mm). Table 1 shows the results of evaluation by compressing the shock absorber in the vertical direction (length direction).

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0032

[Correction method] Deleted

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Seiji Negishi 2-1-1 Katata, Otsu City, Shiga Prefecture Inside Toyobo Co., Ltd. Research Institute (72) Inventor Chisato Nonomura 2-1-1 Katata, Otsu City, Shiga Prefecture Toyobo Co., Ltd.

Claims (3)

[Claims] 1. A flexural modulus of 500 to 5000 kg / cm.
^The hollow part surrounded by the partition wall formed of the resin of ² , has a structure formed continuously and in multiple layers in the same direction, the cross-sectional shape is a honeycomb-shaped shock absorber, A structure in which a cavity partition wall of the shock absorber is buckled and deformed, and a reaction force / compression rate curve at the time of compression in the longitudinal direction of the shock absorber satisfies the following (a) and (b): A resin shock absorber characterized by the following. (A) The yield strength is 100 T / m ² or more. (B) The compression energy absorption is 50 T · m / m ³ or more. 2. The resin shock absorber according to claim 1, wherein a step is provided at a part of the end of the partition wall so that the reaction force is made uniform. 3. A shock absorbing method according to claim 1, wherein shock energy is absorbed by compressive deformation in the longitudinal direction of the shock absorber.