JP3218694B2 - Resin shock absorber - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin shock absorber which can be widely used for roads and quayside walls, building floors and walls, buffers for automobiles, etc., which need to absorb or mitigate shocks. It is about.

[0002]

2. Description of the Related Art Conventional shock absorbers include metal springs,
There are a friction shock absorber, a hydraulic shock absorber, a rubber molded body, and the like, and a combination thereof is also used. However, metal springs have excellent cushioning properties, but have little energy absorption capability. In general, frictional shock absorbers and hydraulic shock absorbers are not only complicated in structure and expensive, but also have problems such as extremely large dependence of the spring constant on the deformation speed and lack of restorability. In addition, these shock absorbers are greatly restricted by the use environment such as being difficult to use in water, and maintenance such as rust prevention and waterproofing is indispensable. Rubber molded products have the characteristic of good resilience, but since the material has a low elastic modulus, it is necessary to use a large amount of material in order to secure a satisfactory amount of shock absorption. It is difficult to increase the size because it is heavy. Further, these shock absorbers are convenient for alleviating the impact of a narrow pressure receiving portion, but are difficult to apply to a structure having a uniform cushioning property over a wide area such as a road side wall or a floor or a wall of a building.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and its object is to provide a light-weight and simple structure which is large in comparison with the reaction force. It has excellent energy absorption efficiency, excellent resilience, and has rust prevention, water resistance, and weather resistance that can be used regardless of whether it is in the air or under the sea, and is maintenance-free. It is an object of the present invention to obtain a resin shock absorber that can be expanded and assembled and can exhibit uniform cushioning properties over a wide area.

[0004]

Means for Solving the Problems The structure of the shock absorber according to the present invention, which can solve the above problems, is an arch-shaped or dome-shaped resin formed with a resin having a flexural modulus of 1,000 to 20,000 kg / cm ^2. Or a honeycomb-shaped large deformable part,
A resin shock absorber made by laminating a plurality of resin shock absorbing units erected on a perforated or non-perforated flat plate. The gist is that the compression ratio curve is configured to satisfy the following conditions. (a) The yield strength is 2 to 25 ton / m ² , (b) The compression energy absorption efficiency is 50% or more, and (c) The yield point is within 15% of the compressibility.

[0005]

[Action] resinous impact-absorbing member of the present invention uses a resin as flexural modulus of 1,000 ~20,000kg / cm ² mentioned above as a material, arched in porous or nonporous on the flat plate by using this , Having a structure in which a plurality of dome-shaped or honeycomb-shaped large deformable parts are erected, and the bending elastic modulus is 1,00
Examples of the resin having a weight of 0 to 20,000 kg / cm ² include a thermoplastic polyester elastomer, a polyolefin elastomer, a polyamide elastomer, a polyurethane 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.

By the way, in the case of a resin having a flexural modulus of less than 1,000 kg / cm ² , the spring constant of the obtained shock absorber is insufficient, so that the thickness of the constituent elements must be increased in order to have a satisfactory energy absorption performance. And the impact absorber becomes large and heavy, which is not in accordance with the gist of the present invention.

On the other hand, if the flexural modulus exceeds 20,000 kg / cm ² , the resulting shock absorber becomes too rigid and lacks flexibility, and stress concentration occurs when subjected to compressive force. It becomes easy to break and becomes hard to withstand repeated use. In addition, if the thickness of the large deformable part is reduced to suppress rigidity, the shock absorber will have good flexibility, but when deformed by a large compressive force, the components will be locally broken like paper. As a result, the object loses its elasticity and is hardly restored, so that the object of the present invention cannot be achieved.

On the other hand, the flexural modulus is 1,000 to 20,000
When resin of kg / cm ² is used as the material, the rise of the stress of the shock absorber or the yield stress can be increased as necessary by changing the shape of the large deformable part described later. Because it can be made, it is possible to make a lightweight absorber without making the thickness extremely thick like a conventionally used rubber molded body, and it is not easy to break down due to stress concentration during compression .

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 structure as described in detail below using a resin satisfying the above-mentioned requirements of the flexural modulus. I do. That is, FIGS. 1 to 3 exemplify the structure of the spring element A constituting the shock absorber according to the present invention, in which a large deformable portion 1 having an arched or dome shape is provided on a perforated or non-perforated flat plate 3. The shock absorber is formed by arranging a large number of spring elements A having such a structure in the vertical and horizontal directions and integrally forming the shape and structure as shown in FIG. 4 (partial side view). Is configured. The flat plate 3 and the large deformable portion 1 of the spring element A may be provided with a parallel portion 2 at the top of the large deformable portion 1 or a through hole 4 if necessary.
It is preferable to make it easier to join or to make sure that the tops are securely contacted with each other when compressed and compressed when the integrally molded articles are joined back-to-back as described below. .

In the illustrated spring element A, a flat plate 3
Constitutes an impact force receiving surface, while the large deformable portion 1 constitutes an elastic deformation or buckling deformation portion for relaxing or absorbing the impact force. There is no limitation on the shape as long as it has legs or walls that are erected in the diagonal direction, and arches of various shapes and structures including arcs, trapezoids, etc. as shown in the figures, or It can be formed in a dome shape. Further, the large deformable portion 1 may be formed into a honeycomb shape as shown in FIG. 5, for example, to have a shock absorbing function.

In putting the shock absorber of the present invention to practical use, for example, as shown in FIG. 6, a set of two shock absorbers is superimposed back to back, and furthermore, a shock force required according to the application place is required. In order to achieve the object of the present invention, stress / compression when the shock absorber is compressed in the direction of the arrow in FIG. 6 is used. It is necessary that the yield strength confirmed by the rate curve is 2 to 25 ton / m ² and the compression energy absorption efficiency is 50% or more.

Here, the stress / compression ratio curve (hereinafter, may be referred to as an SS curve) is, for example, when a compressive force is applied to the shock absorber from above and below as schematically shown in FIG. It is a graph which shows the correlation of a stress (compression force / pressure receiving area) and a compressibility, and an SS curve rises sharply in the initial stage of compression substantially in proportion to a compressibility, and then a curve gradually becomes gentle. The yield point at which the maximum stress is locally reached is reached, where the large deformable portion of the shock absorber yields and the stress tends to slightly decrease, or may gradually increase depending on the shape. . Thereafter, when the compression is further continued, the SS curve rapidly rises again due to the reduction of the gap, and the stress becomes extremely high with a slight increase in the compression ratio.

In this SS curve, the yield strength means a stress value showing a maximum after the first rise, and the compressive energy absorption efficiency means a yield strength or a stress which gradually rises at the last rise. When showing
SS up to the compression ratio when showing a value equivalent to the maximum value
The area surrounded by the curve (shaded area X in FIG. 7)
It means the percentage of the value divided by the product of the maximum stress up to the compressibility and the compressibility (the shaded area Y in FIG. 7).

Although the yield strength does not always coincide with the maximum stress value, the yield strength is a value close to the maximum stress applied to the colliding object when the shock absorber receives an impact force, and is considered as a standard of the maximum stress value. When the yield strength is insufficient, the function as an 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 on the colliding object cannot be sufficiently reduced. Further, as is apparent from the above description, in order to increase the compression energy absorption efficiency, it is necessary to make the hatched area X as close as possible to the hatched area Y (that is, make the area X closer to a rectangle).
It is effective to make the first rise of the −S curve as sharp as possible and to minimize the decrease in stress after passing the yield point.

From these viewpoints, various studies have been made on the physical properties required of the shock absorber according to the present invention. As a result, it is necessary to sufficiently reduce the impact force without giving an excessive reaction force to the collision object. The yield strength of the absorber is within the range of ² to 25 tons / m ² and the compression energy absorption efficiency is 50%.
As described above, it is more preferable that the content be 75% or more. It has been clarified that the shock absorber of the present invention sufficiently satisfies such required characteristics.

By the way, in a conventionally known shock absorber such as a rubber molded product, for example, as shown in FIG.
Not only is the rise of the S-curve slow, but the yield point shows a relatively high value, the reaction force at the time of yield is large, and the subsequent decrease in stress is relatively large, and the compression ratio is relatively small. To show the final rise.

However, 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 an actual example in FIG. Is not only steep, but also shows an appropriate yield strength. After changing the compressibility further, it keeps a substantially constant stress for a while, then shows a final sudden rise, and as a result, more than 50% Alternatively, it has a very high compression energy absorption efficiency of 75% or more. As described above, it is effective to sharpen the first rise of the SS curve to increase the energy absorption efficiency, as described above. The flexural modulus of the resin and the shape and thickness of the large deformable portion should be selected so as to indicate the yield point.

In the example of FIG. 4, a plurality of large deformable portions having the same shape and size are erected as spring elements. However, two or three or more large deformable portions having different shapes and sizes are provided as necessary. A number of possible parts may be erected in an arbitrary arrangement, and furthermore, unit shock absorbers of different structures provided with large deformable parts having different shapes and dimensions are overlapped with each other to form a shock absorber. It is also possible to configure.

Further, there is no particular limitation on the shape, structure, wall thickness, etc. of the large deformable portion, and as described above, it can be appropriately changed according to the application and purpose. In order to secure the yield strength and compression energy absorption efficiency of the steel and to increase the weight and the restoring force after repeated use, for example, the ratio of the height H of the large deformable portion to its span length B in FIG. It is desirable to select the shape so that H / B = 0.3 to 1.5. The reason is H /
If B is less than 0.3, the large deformable portion becomes insufficient in height, and the weight ratio occupied by the flat portion increases, making it difficult to utilize the purpose of weight reduction. On the other hand, when H / B exceeds 1.5, large deformation occurs. This is because the leg length of the possible portion becomes too long, the bending rigidity tends to be insufficient, and the large deformable portion tends to fall down in an irregular direction, and the restoring force tends to deteriorate.

In order to increase the durability of the shock absorber according to the present invention so that it can withstand repeated use, the type and the type of the resin are set so that the compression ratio becomes 50% or more and the restoration ratio after deloading becomes 90% or more. It is desired to select the shape and structure of the large deformable portion.

[0021] Incidentally, there has been an example in which a rubber tire is conventionally used for impact mitigation of a ship or the like, and a rubber impact mitigation material produced according to this is also known, but these are all very heavy. In addition to this, an excessive stress (repulsive force) is generated by a compressive force of at most several percent, and only a small amount of impact energy can be absorbed. As described above, by giving a dashpot and a spring-like energy absorption behavior by combining the viscoelastic properties of resin with moderate bending elasticity and its shape as described above, it is possible to absorb impact energy extremely efficiently, Damage to the collision object due to impact can be minimized.

As a method for producing the shock absorber according to the present invention, any method such as injection molding, extrusion molding or press molding can be adopted. When a plurality of these are further assembled to form an aggregate, Each of the unit absorbers can be joined up and down or vertically and horizontally by a metal rivet, a plastic rivet, or the like, and can be expanded to a predetermined size. Alternatively, a method may be employed in which mounting bolts, bosses, and holes are provided in advance in the unit absorber, and connected and fixed by self-snapping using these. There is also a method in which the unit absorbers are heat-sealed with each other to collectively integrate them. Particularly convenient and preferable as a method of assembling the assembly is to assemble and expand in the vertical, horizontal, and height directions by using the fitting of the connection hole or the self-snap uneven portion provided in each unit absorber. Is the way.

The resin shock absorber of the present invention can be mounted in a usual manner, for example, by mounting it to another structure through a hole or a bolt provided in a flat plate portion constituting the absorber. Of course, the mounting method is not limited at all.

The preferred types of the resin used in the present invention are as described above, but these resins may be added to various kinds of stabilizers such as a thermal antioxidant and an ultraviolet absorber according to the application or purpose. Fillers such as dyes and pigments, 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, mold release agents, etc. It is also possible to modify by adding an additive.

[0025]

The present invention is constituted as described above. By using a resin having a specified flexural modulus and by specifying its shape and structure, it has excellent shock absorbing properties and is lightweight. Thus, it is possible to provide a shock absorber that can be easily expanded and assembled in dimensions and sizes according to the purpose of use, and that exhibits excellent corrosion resistance, water resistance, and weather resistance regardless of whether it is in the air or in the sea. The shock absorber can be effectively used as a structure having a uniform cushioning property over a large area, such as a cushion on the side wall of a road or a quay, a cushion floor of a building, or the like, 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 Using a polyester elastomer "Perprene P-280B" (black color) manufactured by Toyobo Co., Ltd., an impact absorber 21 cm × 21 cm having eight arch-shaped large deformable portions shown in FIG. × Injection molded 3.3 cm in height. The absorber was able to compress substantially up to 80% vertically.
Also, this absorber is joined by resin rivets in the vertical and horizontal directions and in the height direction to assemble the shock absorber 101 cm × 10
1 cm × 99 cm was produced (Example 1). Based on this assembly structure, the features of the absorber of the present invention will be clarified from the examples and comparative examples in Table 1.

In Example 2, a shock absorber was prepared by injection molding the same molded product as in Example 1 using a polyolefin elastomer "Sumitomo TPE3255" manufactured by Sumitomo Chemical Co., Ltd. Example 3 is based on Toyobo Co., Ltd. shown in Example 1.
Polyester elastomer "Perprene P-28"
FIG. 6 is an example of a honeycomb shape shown in FIG. 5 manufactured using “0B” (black color).

Comparative Example 4 is a commercial product made of chloroprene.
In Reference Example 5, the polyester elastomer "Perprene P-280B" (black) manufactured by Toyobo Co., Ltd. shown in Example 1 was used, and FIG. 1 (however, H / L> 1) .5) injection molded into the shape of
Reference Example 6 is injection-molded in Reference Example 5 into a shape of H / L <0.3. The results are collectively shown in Table 1. The meanings of the evaluation items in Table 1 are as follows.

[Evaluation method] Unit volume weight: A value obtained by dividing the weight (kg) of the shock absorber by the volume obtained by multiplying the maximum length, width and height of each piece of the shock absorber. Flexural modulus of resin: Measured by generally used ASTM-D790. Maximum stress: As shown in FIG. 7, when compressed at a constant speed of 50 mm / min, the stress-compression ratio curve rises almost in proportion to the compression ratio in the early stage of compression, and then gradually becomes gentler, and gradually becomes local. It reaches the yield point that shows the maximum stress, and refers to the stress corresponding to this yield point. Yield point compression ratio: A value (%) expressed as a percentage (cm) obtained by dividing the compression displacement (cm) corresponding to the yield strength by the length in the compression direction before compression. Compression at final rise: stress-
In the compression ratio curve, it is the compression ratio corresponding to the stress equal to the greater of the following (1) or (2) at the time of the last rapid rise. (1) Yield strength, (2) The maximum value when the stress gradually increases again after passing the yield point in the stress-compression ratio curve.

Compressive energy absorption efficiency (%): In the stress-compression ratio curve, the area surrounded by the stress-compression ratio curve up to the compression ratio at the final rise is divided by the product of the compression ratio at the final rise and its maximum stress. Means the percentage of the measured value. The amount of absorbed energy per unit volume ^{(T · m / m 3)} :
It is a value obtained by dividing the amount of absorbed energy by the volume of the shock absorber. Absorbed energy per unit weight: a value (Tm / T) obtained by dividing the amount of absorbed energy by the weight of the shock absorber. Absorbed energy per unit volume / yield strength (reaction force): A value (Tm / m ³ / T) obtained by dividing the absorbed energy per unit volume by the yield strength.

[0032]

[Table 1]

As is clear from Table 1, the absorber of the present invention is lighter in weight and can absorb a greater impact energy with a smaller reaction force than the conventional impact absorber.
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.

FIGS. 10 and 11 show the stress-compression ratio curves of the shock absorber of Example 1 and the shock absorber of Comparative Example 4, and the shock absorber of Comparative Example 4 has a yield strength. Not only is it very high, the reaction force at the time of collision becomes extremely large, but also it can be confirmed from the SS curve that the compression energy absorption efficiency is poor. On the other hand, the shock absorber of Example 1 has an appropriate yield strength, does not exert an extreme reaction force on the colliding object, and has a rectangular SS curve as compared with that of the comparative example. , It can be seen that the compression energy absorption efficiency is very excellent.

When a vehicle having a vehicle weight of 1 Ton collides with a concrete wall to which the resin shock absorber of the present invention obtained in Example 1 was attached at a speed of 10 km / h and an incident angle of 10 °, a bumper portion of the vehicle was obtained. Although some damage was observed, the energy absorber recovered and no damage was observed.

[Brief description of the drawings]

FIG. 1 is a perspective view illustrating a spring element constituting a shock absorber according to the present invention.

FIG. 2 is a perspective view illustrating a spring element constituting the shock absorber according to the present invention.

FIG. 3 is a perspective view illustrating a spring element constituting the shock absorber according to the present invention.

FIG. 4 is a perspective view illustrating a shock absorber according to the present invention.

FIG. 5 is a perspective view illustrating a spring element constituting the shock absorber according to the present invention.

FIG. 6 is an explanatory side view showing an example of use of the shock absorber according to the present invention.

FIG. 7 is an explanatory diagram showing a stress / compression ratio curve of the shock absorber according to the present invention.

FIG. 8 is an explanatory diagram showing a stress / compression ratio curve of a conventional shock absorber.

FIG. 9 is a perspective view showing a spring element of the shock absorber used in the comparative example.

FIG. 10 is a diagram showing a stress / compression ratio curve obtained in the example.

FIG. 11 is a diagram showing a stress / compression ratio curve obtained in a comparative example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Large deformable part 2 Parallel part 3 Flat plate 4 Through hole A Spring element

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Hitoshi Ueno 2-1-1 Katata, Otsu-shi, Shiga Prefecture Toyo Boseki Co., Ltd. (56) References JP-A-2-253023 (JP, A) Japanese Patent Laid-Open No. Sho 50-136682 (JP, A) Japanese Patent Laid-Open No. Sho 50-26695 (JP, A) Japanese Patent Laid-Open No. Hei 4-95626 (JP, A) Japanese Patent Laid-Open No. Hei 2-80824 (JP, A) JP, U) JP-A-2-34840 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F16F 7/00

Claims (1)

(57) [Claims] 1. A plurality of arch-shaped, dome-shaped or honeycomb-shaped large deformable portions formed of resin having a bending elastic modulus of 1,000 to 20,000 kg / cm ² are provided on a perforated or non-perforated flat plate. Sets of laminated resin shock absorbing units
Resin shock absorber, characterized in that the stress / compression rate curve at the time of its compression satisfies the following conditions mainly due to the deformation of the large deformable portion. Resin shock absorber. (a) The yield strength is 2 to 25 ton / m ² , (b) The compression energy absorption efficiency is 50% or more, and (c) The yield point is within 15% of the compressibility.