JP4435034B2 - Energy absorbing material, method for producing the same, and energy absorbing device - Google Patents

Description

The present invention relates to manufacturing method and the energy absorbing device of the energy-absorbing material and its for reducing vibration energy transmitted to seismic buildings and civil engineering structures upon occurrence.

  Conventionally, lead has been used as a material for absorbing vibration energy as described above because of its high ductility or low recrystallization temperature. However, with the recent increase in environmental awareness, there is a possibility of refraining from using lead, such as lead-free solder.

  As an alternative to lead, tin (Sn) with the same high ductility or low recrystallization temperature as lead can be considered. Since tin is harmless, it is also used in the food industry, equipment and household tableware. Widely used.

  However, tin has an allotropic transformation point around 18 ° C. (see Non-Patent Document 1 below) and is usually high-temperature type β-Sn, but when it is extremely cold, it transforms into low-temperature type α-Sn. There is a fear. Since α-Sn is hard and brittle, there is a problem that when allotropic transformation occurs, the mechanical properties change and the energy absorption performance is not stable. Further, it is generally known that the phase expands and collapses into a sand when it is transformed from the β phase to the α phase. For this reason, there is a problem that it is difficult to use tin as an energy absorbing material at a low temperature.

  In order to suppress the allotropic transformation as described above, there is a method of alloying by adding bismuth, cadmium, gold, silver, and antimony to tin, but the purity of the tin is lowered by the additive, and the ductility is reduced or recycled. There was a problem that the crystal temperature increased.

  On the other hand, Patent Documents 1 and 2 below have been proposed as energy absorbers that reduce vibration energy transmitted to buildings, civil structures, and the like when an earthquake occurs. FIG. 15 shows an example, and the energy absorbing device A of this example is a central portion of a laminate 3 in which a plurality of hard plates 1 such as steel plates and elastic bodies 2 such as rubber are alternately laminated in the vertical direction. Further, a hollow portion 3a penetrating in the vertical direction is provided, and an energy absorber 4 made of an elastic-plastic material such as lead that absorbs vibration energy such as an earthquake is accommodated in the hollow portion 3a. In FIG. 15, the hatching of the hard plate 1, the elastic body 2, and the energy absorber 4 (hatched lines indicating the cross section) is omitted to avoid complication.

  As shown in FIG. 15, mounting plates 6 are integrally attached to both the upper and lower ends of the laminate 3 and the energy absorber 4 via a substrate 5, respectively, and the mounting plates 6 are constructed with bolts or the like (not shown). It is a structure to be attached to an object or a civil engineering structure. Specifically, for example, in a building such as a building as shown in FIG. 16, between the upper structure B such as the building and the lower structure C such as the base, and in FIG. In a civil structure such as a bridge as shown, one or a plurality of the energy absorbing devices A are arranged between an upper structure B such as a bridge girder and a lower structure C such as a pier, A bolt or the like is inserted into the mounting holes (not shown) formed in the upper and lower mounting plates 6 of each energy absorbing device A and is mounted on the structures B and C.

  The energy absorbing device A arranged between the upper and lower structures B and C as described above is designed to reduce seismic energy by deforming in the horizontal direction when an earthquake occurs while stably supporting a building or the like. It functions as both a seismic isolation isolator and a seismic isolation damper. As a result, the installation space can be reduced and the workability can be improved as compared with the case where the isolator and the damper are separately arranged.

  By the way, in the said patent document 2, when manufacturing the above energy absorption apparatus, applying the hydrostatic pressure equivalent to or more than the shear yield stress to the energy absorber which consists of an elastic-plastic material is proposed. Has been. This is a necessary procedure for integrating the energy absorber with the laminate, and by this, the energy absorber and the laminate are integrally deformed so that vibration energy such as an earthquake can be absorbed. That is, when the energy absorber is deformed by an earthquake or the like, the energy absorber expands and contracts in the length direction, and vibration energy is reduced by plastic deformation such as diameter reduction and expansion in the direction perpendicular to the length direction. Will absorb.

  However, in the vicinity of the outer periphery of the energy absorber, the energy absorber is actually seized due to the frictional force of the hollow surface of the laminated rubber or the energy absorber biting into the laminate. When subjected to repeated deformation due to, for example, the corner of the energy absorber gradually sags, the diameter bulges near the end of the energy absorber, and the diameter shrinks near the center of the energy absorber. This is caused by the difference in the state of change of the energy absorber in the vicinity of the end and the center of the energy absorber, which is mainly affected by the frictional force or the energy absorber. This is considered to be caused by the difference in deformation between the outer peripheral portion and the inside of the energy absorber.

  As a result, since the deformation direction and amount of deformation of the energy absorber are different near both ends and near the center of the energy absorber, the worst energy absorber is cracked in addition to the sagging of the corners and the expansion and contraction of the diameter. There is a risk of problems such as entering. Further, when the energy absorber is in the above state, there is a problem that not only the predetermined energy amount cannot be stably absorbed, but also the durability is deteriorated.

  On the other hand, in order to obtain an energy absorber having a larger damping force, it is necessary to increase the diameter of the energy absorber in the laminate or increase the number of installed energy absorbers. For example, it is necessary to insert the energy absorber into the hollow portion of the laminate with a greater force at the time of manufacture, which not only requires large-scale equipment, but also the inner surface of the hollow portion of the energy absorber and the laminate. As the frictional force and the bite increase, the above-mentioned problems become more serious. In addition, increasing the number of installed energy absorbers is not always practical because a large installation space and construction cost are required during construction.

Magazine "Metal" 1987 vol. 57 (July issue) issued by Agne Technology Center Co., Ltd. ("Tin properties") Japanese Patent Publication No. 61-17984 Japanese Patent No. 3360828

The present invention has been proposed in view of the above problems. By adjusting the amount of metal added to tin, the mechanical properties do not change even at low temperatures, and the damping force is large even if the diameter is small. and to provide easy-low cost of energy absorbing material and its manufacturing method and an energy absorbing device for absorbing vibrations and the like. Also by limiting the amount, and to provide an energy absorbing material and its manufacturing method and an energy absorbing device with no accumulation of recrystallized fatigue at normal temperature. By further limiting the amount has lead least equivalent elongation (ductility), the energy absorbing performance to provide a manufacturing method and the energy absorbing device of stable even repetitive durability and high energy-absorbing material and its For the purpose.

In order to achieve the above object, an energy absorbing material, a manufacturing method thereof, and an energy absorbing device according to the present invention have the following configurations. That is, the energy absorbing material according to the present invention is an energy absorbing material for absorbing vibration energy such as an earthquake, a main component 99% by weight or more of tin, to which was added bismuth scan as an additive metal alloy consists phased elastoplastic material, and the proportion of the additive metal for the elastic-plastic material is 5 wt% or less.

A method for producing an energy absorbing material according to the present invention is a method for producing an energy absorbing material for absorbing vibration energy such as an earthquake, and mainly comprises tin having a purity of 99% by weight or more, and bismuth as an additive metal. An energy absorbing material made of an elastic-plastic material is produced by adding and alloying at a ratio of 5% by weight or less .

  Moreover, the energy absorbing device according to the present invention is provided with a hollow portion penetrating in the vertical direction in a laminated body formed by alternately laminating a plurality of hard plates such as steel plates and elastic bodies such as rubber in the vertical direction, and in the hollow portion. In an energy absorption device that houses and arranges an energy absorber that absorbs vibration energy such as an earthquake, the energy absorber is formed of the energy absorbing material as described above.

  Furthermore, another energy absorbing device according to the present invention is provided with an advancing / retreating rod concentrically and axially movable in a cylindrical cylinder, housing an energy absorber around the advancing / retreating rod in the cylinder, In an energy absorption device that absorbs vibration energy by a resistance portion such as a convex portion provided on a cylinder or an advancing / retreating rod relatively moving in the energy absorber when vibration is caused by an earthquake or the like, the energy absorber is as described above. It is formed by an energy absorbing material.

Energy absorbing material and its manufacturing method and an energy-absorbing device according to the invention, again with the construction as described above, does not change the mechanical properties even at low temperatures, large damping force with a small diameter, also at room temperature It is possible to provide an energy absorbing material that is crystallized and does not accumulate fatigue, and further has an elongation equal to or greater than that of lead, a method for manufacturing the same, and an energy absorbing device . Therefore, the energy absorbing performance can provide a stable and, repeating durability high energy-absorbing material and its manufacturing method and an energy absorber.

It will be specifically described below energy-absorbing material and its manufacturing method and an energy-absorbing device according to the present invention.

  In general, in an energy absorbing device that absorbs vibrations such as earthquakes, it is generally preferable to follow the seismic isolation material by 20% or more, preferably 40% or more, from the amount of displacement of earthquakes such as buildings. However, it is naturally desirable that the energy absorbing material can ensure an elongation of 20% or more, preferably 40% or more.

  Therefore, in the present invention, it is an energy absorbing material for absorbing vibration energy such as earthquakes, mainly composed of tin having a purity of 99% by weight or more, and any one of bismuth, cadmium, gold, silver, and antimony. Or an elastic-plastic material alloyed by adding one or more metals as an additive metal, the ratio of the additive metal to the elastic-plastic material is 40% by weight or less, and the elongation of the elastic-plastic material The amount is set to be 20% or more.

  FIG. 1 shows a mixture ratio (wt%) when 99% by weight tin is used as the main component of the elastoplastic material and bismuth is mixed as an additive metal to form an alloy, and an elastoplastic material formed from the alloy. It shows the maximum tensile elongation (%) until fracture when a tensile test based on JIS Z 2201 is performed using the test piece. In addition, as a test piece of the tensile test, an alloy formed in the size and shape as shown in FIG. 2 was used, and the test was performed at a temperature of 20 ° C. and a speed of 500 mm / min. The unit of the dimension in FIG. 2 is mm. In addition, the test was conducted with the number of test specimens N = 3 in consideration of the variation of the test specimens. The same applies to the test described later. Furthermore, the mixing amount of the bismuth was appropriately changed within the range of 0.2 wt% to 50 wt%. For reference, the case of only 99% by weight of tin (mixing amount of bismuth 0% by weight) is also shown in FIG.

  As a result, when bismuth is mixed with 99% by weight tin as an elastic-plastic material and alloyed, the maximum elongation decreases as the amount of bismuth is gradually increased. However, the rate of decrease rapidly decreases up to the mixing amount of about 0 to 10% by weight, but thereafter, it gradually decreases from 40% to 20% in the amount of mixing up to about 40% by weight, and the mixing amount of 40% by weight. It can be seen that when the amount exceeds%, the amount of elongation decreases rapidly.

  As is clear from FIG. 1 above, if the addition amount (mixing amount) of bismuth is 10% by weight or less, the elongation amount is 40% or more, and if the addition amount of bismuth is 1% by weight or less, 60% It can be seen that the above amount of elongation can be obtained.

  FIG. 3 shows the tensile strength of the tensile test performed in FIG. 1 (tensile strength until breakage) when a tensile test was performed by forming a test piece similar to the above using only 99% by weight of tin. The ratio to the tensile strength (tensile strength ratio) is shown. As a result, it can be seen that the tensile strength increases as the mixing amount of the metal increases. However, the rate of increase decreases when the mixing amount is about 40% by weight. That is, when the mixing amount is suppressed to about 40% by weight or less, the mixing range is efficient in improving the tensile strength.

  Moreover, said result has shown that tensile strength can be changed freely with the mixing amount of a metal. That is, for example, when a laminated rubber laminate having a proof strength of about 3 times is desired, an elastic-plastic material in which about 10% by weight of an additive metal is added to the main body of the elastic-plastic material may be used as an energy absorber (core body). That is. Summing up the above, it can be seen that the balance between the amount of elongation and the tensile strength falls within the best range when the mixing amount is suppressed to about 40% by weight or less.

  Next, a test using tin having a purity of 99.9% by weight will be described. Using the test specimens shown in Table 1 below, the effects and effects of the additives on the mechanical properties and recrystallization temperature were confirmed. As a typical additive, bismuth was used. For comparison, a similar test was conducted for lead with a purity of 99.99% by weight. Furthermore, tin having a purity of 99.99% by weight to 99% by weight was used, and the influence and effect of the purity on the mechanical properties were also confirmed.

  FIG. 4 shows the tensile strength in the purity dependence test. That is, it is a graph showing the results of a tensile test of pure tin (1) to (3), which are the test bodies in Table 1, and more specifically, the magnitude of the load required to pull each of the test bodies at the above speed. It is a graph which shows. In the test, all of the tins had higher tensile strength than lead, and high reproducibility was observed with 99.99 wt% to 99.9 wt% tin.

  FIG. 5 shows the elongation in the purity dependence test. That is, it is a graph showing the elongation (%) when pure tin (1) to (3), which are the test bodies of Table 1, are pulled at the above speed. In the test, the elongation was almost constant regardless of the purity of tin.

  FIG. 6 shows the tensile strength in the additive dependency test. That is, a tensile test was performed in the same manner as in FIG. 4 with respect to the tin alloy (1) which is the test body of Table 1 above, that is, a tin alloy obtained by adding a predetermined amount of bismuth as an additive to 99.9 wt% purity tin. It is a graph which shows the result. In the test, the tensile strength increased as the amount of additive increased. It can be confirmed that the tensile strength is higher than that of lead at any added amount.

  FIG. 7 shows the elongation in the additive dependency test. That is, the graph shows the elongation (%) when a tin alloy (1), which is the specimen of Table 1 above, is added with a predetermined amount of bismuth as an additive and pulled in the same manner as in FIG. is there. In this test, the elongation decreases as the amount of the additive increases, but from the approximate curve obtained from this test, within 5.0% by weight of the additive, the elongation is equivalent to 99.99% by weight of lead. It can be seen that within 4.0 wt%, the elongation is greater than 99.99 wt% lead.

  Next, in order to confirm the presence or absence of recrystallization near normal temperature, the cross-sectional structure before and after the tensile test of a test body in which bismuth was added to 5.0% by weight of tin having a purity of 99.9% by weight was observed with a microscope. When recrystallization does not occur, the crystal grains have a shape elongated in the axial direction by a tensile test, but when recrystallization occurs, the crystal grains become small and have a substantially circular shape. In addition, it is possible to confirm to what extent the recrystallization at 20 ° C. occurs by observing the cross-sectional structure before and after the tensile test.

  FIG. 8 is a photomicrograph of the cross-sectional structure before the test when bismuth is added at 5.0% by weight to 99.9% by weight of tin, and FIG. 9 is a photomicrograph of the cross-sectional structure after 2 days of the test. Compared with the crystal grains before the test of FIG. 8, it can be seen that the particle diameter after 2 days of the test of FIG. 9 is small and the shape is close to a circle. As a result, it was confirmed that recrystallization was performed at 20 ° C. within at least 5.0 wt%.

  In the embodiment, tin having a purity of 99% by weight to 99.9% by weight is used as the main body of the elastoplastic material, but tin having a higher purity than that, for example, 99.99% by weight of purity may be used. The additive metal added to the main tin is not limited to bismuth, and any one or more of cadmium, gold, silver and antimony may be used in combination. Even if it exists, the effect similar to the above is acquired.

  Furthermore, when the additive metal is 40% by weight or less, the mechanical properties do not change even at low temperatures, and the damping force increases even if the diameter is small, but if the additive metal is 10% by weight or less, the elongation of the elastic-plastic material is increased. Is 40% or more, and recrystallization at room temperature can be expected if the additive metal is 5% by weight or less. Furthermore, when the additive metal was made 4.0% by weight or less, it was clarified that elongation equal to or higher than that of lead was obtained, and that it could be used favorably as a material for absorbing vibration energy. Further, since the strength can be changed by changing the amount of the additive metal added, the performance of the damper can be freely adjusted.

  FIGS. 10 and 11 show an embodiment of an energy absorbing device using the energy absorbing material produced as described above as an energy absorber, FIG. 10 is a perspective view, and FIG. 11 is a longitudinal view thereof. Note that members having the same functions as those in the conventional example will be described with the same reference numerals.

  The energy absorbing device A of the present embodiment is a laminated body in which a hard plate 1 such as a steel plate and an elastic body 2 such as rubber are alternately laminated in the vertical direction and integrated with an adhesive or the like as in the conventional example. 3 is provided with a hollow portion 3a penetrating in the vertical direction, and an energy absorber 4 that absorbs vibration energy such as earthquake is accommodated in the hollow portion 3a.

  As the energy absorber 4, in this embodiment, tin having a purity of 99% by weight or more is mixed by mixing bismuth at a ratio of 40% by weight or less with respect to the above tin, and the alloy is fractured by a tensile test of the alloy. What was formed with the energy absorption material whose elongation amount until it is 20% or more was used.

  In the present embodiment, a carbon steel plate is used as the hard plate 1 constituting the laminate 3, but a stainless steel plate, another metal plate, a hard synthetic resin plate, or the like can also be used. In the present embodiment, natural rubber is used as the elastic body 2, but synthetic rubber, soft synthetic resin, or the like may be used. In the longitudinal sectional view of FIG. 11, the hatching of the hard plate 1, the elastic body 2, and the energy absorber 4 is omitted.

  A mounting plate 6 is integrally attached to the upper and lower ends of the laminate 3 and the energy absorber 4 configured as described above with bolts 7 or the like via the substrate 5 as in the conventional example. An attachment hole 6 a is formed in 6. As in the conventional examples of FIGS. 16 and 17, one or a plurality of the energy absorbing devices A are provided between an upper structure B such as a building or a structure and a lower structure C such as a base. The bolts 8 and the like are inserted into the mounting holes 6a provided in the energy absorbing devices A and attached to the structures B and C.

  As described above, the energy absorber 4 of the energy absorber A disposed between the upper and lower structures B and C is tin having a purity of 99% by weight or more and bismuth in a ratio of 40% by weight or less with respect to the tin. Since an energy absorbing material having an elongation of 20% or more until it was fractured in a tensile test of the alloy by mixing was used, vibration such as an earthquake could be efficiently absorbed.

  FIG. 12 is a displacement history curve diagram (P-δ diagram) at the time of 50% deformation when performing a four-cycle displacement test using the energy absorbing device of the above-described embodiment as a test body. It can be easily inferred that the durability is also good. Further, after the above test, the specimen was halved and the energy absorber was observed. As a result, no cracks or breaks were observed.

  13 and 14 show another embodiment of an energy absorbing device using the energy absorbing material as an energy absorber. FIG. 13 is a longitudinal sectional view of the energy absorbing device, and FIG. 14 shows the energy absorbing device. The example applied as a seismic isolation device or a vibration control device in a building such as a building is shown.

  As shown in FIG. 13, the energy absorbing device A <b> 1 of the present embodiment is provided with an advancing / retreating rod 12 in a cylindrical cylinder 11 so as to be concentrically movable relative to the axial direction. In addition, the energy absorber 13 made of the energy absorbing material is accommodated, and a resistance portion 12c such as a convex portion provided on the cylinder 11 or the forward / backward rod 12 is relatively moved in the energy absorber 13 when vibration is caused by an earthquake or the like. In this configuration, vibration energy is attenuated or absorbed by movement. In the figure, 14 is a bearing that receives the advance / retreat rod 12, 15 and 16 are cylinder closing caps that also serve as guide cylinders of the advance / retreat rod 12, and both caps 15 and 16 are screwed to both ends of the cylinder 11. .

  In FIG. 14, the energy absorbing device A1 configured as described above is arranged between an upper structure B of a building such as a building and a lower structure C such as a base thereof, and One end 12 a is connected to the upper structure B via the bracket 17, and the end of the cylinder 11 on the cap 16 side is connected to the lower structure C via the bracket 18. In the illustrated example, the energy absorbing device A1 and the energy absorbing device A are used in combination. However, only the energy absorbing device A1 can be used alone or in combination with other energy absorbing devices.

  In either case, when the energy absorbing device A1 is disposed between the upper structure B and the lower structure C, the upper structure B and the lower structure C are relatively moved in the horizontal direction due to an earthquake or the like. Correspondingly, the cylinder 11 and the advance / retreat rod 12 of the energy absorbing device A1 move relative to each other, and the resistance portion 12c such as the convex portion provided on the cylinder 11 or the advance / retreat rod 12 moves in the energy absorber 13. The vibration energy can be attenuated or absorbed by resistance.

  Actually, as the energy absorber 13 of the energy absorber A1 shown in FIG. 13 and FIG. 14, as in the energy absorber 4 of the energy absorber A of FIG. 10 and FIG. Bismuth is mixed with the above tin at a ratio of 40% by weight or less to form an alloy, and when an energy absorbing material having an elongation of 20% or more until the alloy breaks in a tensile test is used, vibration such as an earthquake occurs. It was able to absorb efficiently.

  Further, as the energy absorber 4 and the energy absorber 13, an energy absorbing material in which the mixing ratio of the bismuth with respect to tin having a purity of 99% by weight or more is 10% by weight or less and the elongation is about 40% or more. When used, and when the energy absorbing material having the bismuth mixing ratio of 5% by weight or less and the elongation amount of 50% or more was used, the same or better results were obtained. In addition, even better results were obtained when the purity of tin in each of the above embodiments was 99.9% by weight or more, and further 99.99% by weight or more.

  In the above embodiment, bismuth is used as an additive metal added to tin and alloyed. However, the present invention is not limited to this, and any one or two of cadmium, gold, silver, and antimony including bismuth are used. It is possible to use a mixture of seeds or more, and the same result as described above can be obtained.

  Further, as the energy absorber 4 and the energy absorber 13, bismuth, antimony, lead, or an alloy thereof is added to tin having a purity of 99.9% by weight or more within a range of 0.01 to 4.0% by weight. Even in this case, the same or better results can be obtained.

  As described above, according to the present invention, the mechanical properties do not change even at a low temperature, the damping force is large even when the diameter is small, and the fatigue is accumulated by recrystallization at room temperature. In addition to the above, for example, Japanese Patent Laid-Open No. 2000 previously proposed by the applicant of the present application can provide an energy absorbing material having an elongation equal to or greater than that of lead and an energy absorbing device using the same. As a tin damper in place of a lead damper as described in Japanese Patent No. 2404032 or as a seismic isolation device, damping device or damping mechanism as disclosed in Japanese Patent Application Laid-Open No. 2000-104787, or as an energy absorbing material or energy absorbing It can also be used as a body, increasing the freedom of their design and choice of materials and increasing industrial applicability.

The graph which shows the elongation amount by the tension test of the energy absorption material by this invention. Explanatory drawing which shows the magnitude | size shape of the test piece used by the tension test. The graph which shows the tensile strength ratio by the tensile test of the said energy absorption material. The graph which shows the tensile strength in a purity dependence test. The graph which shows the elongation in a purity dependence test. The graph which shows the tensile strength in an additive dependence test. The graph which shows the elongation in an additive dependence test. A photomicrograph of a cross-sectional structure before a tensile test. The microscope picture of the cross-sectional structure | tissue 2 days after a tension test. The perspective view which shows one Embodiment of the energy absorption apparatus by this invention. The longitudinal cross-sectional view of the said energy absorption apparatus. The hysteresis curve figure which shows a displacement characteristic in the said energy absorption apparatus. The longitudinal cross-sectional view which shows other embodiment of the energy absorption apparatus by this invention. Explanatory drawing of the example which used said energy absorption apparatus for the building. The longitudinal cross-sectional view which shows an example of the conventional energy absorption apparatus. Explanatory drawing of the example which used the said conventional energy absorption apparatus for the building. Explanatory drawing of the example which used the said conventional energy absorption apparatus for the civil engineering structure.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hard board 2 Elastic body 3 Laminated body 4 Energy absorber 5 Board | substrate 6 Mounting plate 7, 8 Bolt A, A1 Energy absorber B Upper structure C Lower structure

Claims (4)

An energy absorbing material for absorbing vibration energy such as an earthquake, which is made of an elastoplastic material alloyed by adding bismuth as an additive metal to tin having a purity of 99.9% by weight or more . The energy absorbing material, wherein the additive metal has a ratio of bismuth of 0.01 to 4.0% by weight . An energy absorbing material manufacturing method for absorbing vibration energy such as earthquakes, comprising an elastic-plastic material alloyed by adding bismuth as an additive metal to tin having a purity of 99.9% by weight or more In manufacturing the energy absorbing material, the additive metal bismuth is added in a proportion of 0.01 to 4.0% by weight with respect to the elastic-plastic material. In a laminate formed by alternately laminating a hard plate such as a steel plate and an elastic body such as rubber in the vertical direction, a hollow portion penetrating in the vertical direction is provided,
In the energy absorbing device in which an energy absorber that absorbs vibration energy such as earthquake is accommodated in the hollow portion,
An energy absorbing device, wherein the energy absorber is made of the energy absorbing material according to claim 1. In the cylindrical cylinder, advancing and retracting rods are provided concentrically and relatively movable in the axial direction,
An energy absorber is accommodated around the advance / retreat rod in the cylinder,
In an energy absorbing device that absorbs vibration energy by causing a resistance portion such as a convex portion provided on the cylinder or the forward / backward rod to relatively move within the energy absorbing body when vibration is caused by an earthquake or the like,
An energy absorbing device, wherein the energy absorber is made of the energy absorbing material according to claim 1.

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