JP2010185577A - Colloidal damper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a colloidal damper capable of providing a high dissipating energy efficiency η, having excellent economic efficiency and serviceability, and normally operable even under low temperatures. <P>SOLUTION: The colloidal damper 1 includes: a container 2; a piston 4 forming a closed space 3 within the container 2 in cooperation with the container 2 and guided and supported in the container 2 freely reciprocatingly in the axial direction X; a porous body 6 stored in the closed space 3 and having a large number of pores 5; liquid 7 stored in the closed space 3 in the mixed state with the porous body 6, made to flow out from the pores 5 in depressurization and made to flow in to the pores 5 in pressurization; and a piston rod 8 transmitting a reciprocating power F in the axial direction X to be damped to the liquid 7 through the piston 4 so as to pressurize the liquid 7. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a colloidal damper in which a porous body such as silica gel and a liquid are mixed and sealed in a sealed space so that the liquid flows into and out of the pores of the porous body to lose mechanical energy.

  For example, colloidal dampers described in WO 96/18040 pamphlet and WO 01/55616 pamphlet have various preferable characteristics different from conventional fluid dampers such as a wide operating frequency range. Therefore, application to various fields is expected.

  However, the colloidal damper uses a novel principle that the liquid is allowed to flow into the pores of the porous body against the surface tension of the liquid and the mechanical energy is lost. The current situation is that the disappearance efficiency is not well understood.

  The applicant of the present invention has a container, a porous body that is accommodated in the container and has a large number of pores, and is mixed with the porous body in the container and is substantially non-pressurized. In general, the flow into the pores of the porous body is eliminated, while the liquid flowing into the pores of the porous body at the time of pressurization and the reciprocating power to be attenuated are transmitted to the liquid and the liquid is depressurized. And a colloidal damper that can absorb mechanical energy efficiently (Japanese Patent Application No. 2002-204617).

  In the proposed colloidal damper, water, antifreeze, polar fluid, molten metal including mercury, molten lead, molten alloy including molten wood metal, molten salt, and molten flux were used as the liquid.

  By the way, although water is preferable as a liquid to be used from the viewpoint of economy and ease of use, since water usually freezes at 0 ° C., a colloidal damper using water as a liquid operates normally at low temperatures. There is a risk of disappearing.

International Publication No. 96/18040 Pamphlet International Publication No. 01/55616 Pamphlet

  As a result of intensive studies, the present inventors have found that even when water is used as a liquid in a colloidal damper, a certain amount of a certain amount of antifreeze is mixed into the water, even at low temperatures up to −40 ° C. Therefore, the object of the present invention is to obtain a high dissipative energy efficiency η and to be economical and easy to use, and to operate normally even at low temperatures. It is to provide a colloidal damper that can be used.

  The colloidal damper according to the first aspect of the present invention is accommodated in a sealed container, a piston that cooperates with the container to form a sealed space in the container, and is guided and supported by the container so as to be able to reciprocate. In addition, the porous body having a large number of pores and the porous body are mixedly accommodated in the sealed space and are discharged from the pores of the porous body at a reduced pressure, while the porous body is reduced at a pressure increase. Where the liquid consists of water mixed with at least 50% by volume of at least one selected from ethanol, ethylene glycol, propylene glycol and glycerin.

  According to the colloidal damper of the first aspect, since the liquid is composed of water mixed with at least 50% by volume of at least one selected from ethanol, ethylene glycol, propylene glycol and glycerin, ethanol, ethylene glycol, propylene At least one selected from glycol and glycerin is an antifreeze for water, and according to one embodiment, the liquid does not freeze even at low temperatures up to around −40 ° C. Thus, even at low temperatures In addition to being able to operate normally, water is mainly used as a liquid, so it is excellent in economic efficiency and ease of use. In addition, since the surface tension of water can be mainly used, high dissipation energy efficiency η can be obtained. it can.

  For example, when 50% by volume of ethanol is mixed in water, the liquid does not freeze even at a low temperature around −32 ° C., but the surface tension σ of ethanol at 20 ° C. is 22.8 mN / m. Therefore, the dissipative energy efficiency η is lower than other antifreezes such as ethylene glycol, propylene glycol and glycerin because it is much smaller than the surface tension σ (= 72.8 mN / m) of water at 20 ° C.

  Further, when 50% by volume of ethylene glycol is mixed in water, the liquid does not freeze even at a low temperature around −35 ° C., but the surface tension σ of ethylene glycol at 20 ° C. is 48.4 mN / Since m is much larger than ethanol, the dissipated energy efficiency η is higher than ethanol.

  On the other hand, when 50% by volume of propylene glycol is mixed in water, the liquid does not freeze even at a low temperature around −32 ° C. like ethanol, but the surface tension σ of propylene glycol at 20 ° C. Since it is 42.3 mN / m, which is considerably larger than ethanol and almost equivalent to ethylene glycol, the dissipated energy efficiency η is higher than ethanol and is almost equivalent to ethylene glycol.

  When 50% by volume of glycerin was mixed in water, the liquid did not freeze even at low temperatures up to around −40 ° C., and the surface tension σ of glycerin at 20 ° C. was 63.4 mN / m. Because it is much larger than ethylene glycol and propylene glycol and almost equivalent to water, the dissipation energy efficiency η is the highest compared to other antifreezes such as ethanol, ethylene glycol, and propylene glycol, and almost equal to water. Efficiency η is obtained, and glycerin is most preferred as an antifreeze in this sense.

  The liquid is an aqueous solution containing at least 40% by volume of at least one selected from ethanol, ethylene glycol, propylene glycol and glycerin, like the colloidal damper of the second aspect of the present invention. According to the colloidal damper, while the freezing temperature of the liquid rises to around −23 ° C., the dissipated energy efficiency η increases. As a result, from the viewpoint of placing importance on the dissipated energy efficiency η, It is preferable to make it.

In the colloidal damper according to the third aspect of the present invention, the surface defining the pores of the porous body is lyophobic with respect to the liquid, and the porous body and the liquid are the pores of the porous body. the volume and V _P, when the volume of the liquid and V _L, the ratio V _{P /} V _L are accommodated in the closed space with the range a to 2.5 or less than 0.2.

The dissipated energy efficiency η in colloidal damper, depending on the ratio between the pore volume and the volume of liquid contained porous body in a closed space, the pore volume of the porous body and V _P, the volume of the liquid the When _{V L,} the ratio _V P / _{V L} is the high dissipated energy efficiency of 2.5 a from 0.2 to less η is obtained.

When the ratio V _P / V _L is smaller than 0.2, the dissipated energy efficiency η suddenly deteriorates, and even if the ratio V _P / V _L exceeds 2.5, it is difficult to expect improvement in the dissipated energy efficiency η. On the other hand, as a result of not being able to obtain a large travel distance, for example, mechanical vibration energy with a large amplitude cannot be absorbed efficiently.

As in the colloidal damper of the fourth aspect of the present invention, when the ratio V _P / V _L is in the range of 0.35 or more and 1.5 or less, higher dissipated energy efficiency η can be obtained. It is preferable that vibration energy with a relatively large amplitude can be absorbed, and when the ratio V _P / V _L is substantially 1 as in the colloidal damper according to the fifth aspect of the present invention, The vibration can be damped with maximum dissipation energy efficiency η.

  When the average diameter (diameter) of the pores on the surface is d1, the porous body is not less than 10 times the average diameter d1 of the pores and 10000 times as in the colloidal damper of the sixth aspect of the present invention. It is preferably made of a substantially spherical granular material having an average diameter (diameter) d2 in the following range, and is 100 times or more the average diameter d1 of the pores as in the colloidal damper of the seventh aspect of the present invention. More preferably, it is made of a substantially spherical granular material having an average diameter d2 in the range of 5000 times or less. As a specific example, “Sylosphere C1504” (trade name) manufactured by Fuji Silysia Chemical Co. has an average diameter d2 of 4.0 μm and an average diameter d1 of 13.4 nm, and “Chromatorex BU0020 manufactured by Fuji Silysia Chemical Ltd.” (Trade name) has an average diameter d2 of 19.9 μm and an average diameter d1 of 10.5 nm, and “God Ball B-6C” (trade name) manufactured by Suzuki Oil & Fats Co., Ltd. has an average diameter d2 of 2.3 μm. The average diameter d1 is 13.1 nm, and “God Ball B-25C” (trade name) manufactured by Suzuki Oil & Fat Co., Ltd. has an average diameter d2 of 13.0 μm and an average diameter d1 of 13.1 nm.

  The porous body may be a mass of a plurality of substantially spherical granular materials, like the colloidal damper of the eighth aspect of the present invention, and in this case, at least one mass may be accommodated in the sealed space. Instead of this, the porous body may be composed of a plurality of substantially spherical particles dispersedly housed in a sealed space, like the colloidal damper of the ninth aspect of the present invention.

  The pores of the porous body may be arranged so as to constitute a labyrinth (maze) in the porous body. However, in order to dissipate energy preferably, the porous body is smaller than the average diameter d1 of the pores. It is preferable to have at least one hollow part having a large diameter, and the pores communicate with the hollow part.In particular, like the colloidal damper of the tenth aspect of the present invention, the porous body is It consists of a substantially spherical granule having a hollow part, and the pore is preferably opened to the central hollow part at one end and to the outside of the substantially spherical granule at the other end in the substantially spherical granule having a hollow part. In such a porous body, the pores may extend radially from the hollow portion as in the colloidal damper of the eleventh aspect of the present invention. Examples of the former having the labyrinth structure include “Sylosphere” manufactured by Fuji Silysia Chemical Co., Ltd., and examples of the latter having the hollow structure include “God Ball” manufactured by Suzuki Yushi Kogyo Co., Ltd. .

  In a preferred use example of the colloidal damper in the present invention, the pressurized liquid usually flows into the pores of the porous body against its surface tension, and when the liquid is depressurized, the fineness of the porous body is reduced. The liquid that has flowed into the pores flows out of the pores of the porous body due to the surface tension, but in order to obtain high dissipation energy efficiency η, the pores are defined in the flow of the liquid into and out of the pores. It is preferable that the liquid slips and continuously flows on the surface of the porous body. Therefore, as in the colloidal damper of the twelfth aspect of the present invention, when the mean free path of the liquid molecule is Lp, Preferred results are obtained when the body pores have an average diameter d1 where the Knudsen number Kn = Lp / (d1 · 1/2) is greater than 0.01 and less than 0.1.

  In other words, the average diameter d1 of the pores of the porous body is a liquid so that the Knudsen number Kn = Lp / (d1 · 1/2) is larger than 0.01 and smaller than 0.1. It is better to decide in relation to

  The surface of the porous body that defines the pores does not get wet when the liquid flows into and out of the liquid pores, in other words, has a lyophobic property. In the present invention, porous PTFE or porous polystyrene having lyophobic properties with respect to a liquid mainly containing water is preferable as the porous body, but is not limited thereto. Thus, when the porous body itself has no lyophobic property with respect to the liquid, in order to impart lyophobic properties to the porous body, at least as in the colloidal damper of the thirteenth aspect of the present invention. In practice, the surface of the porous body that defines the pores is changed to a liquid that uses the entire surface of the porous body, including the surface in the pores, like the colloidal damper of the fourteenth aspect of the present invention. On the other hand, the lyophobic treatment may be performed by coating with a lyophobic substance having lyophobic properties.

Such a lyophobic substance is a substance having a linear molecular chain, specifically, for example, Si (CH ₃ ) ₂ C _n H _{2n + 1} (where n = _n ), like the colloidal damper of the fifteenth aspect of the present invention. 1-22) or an organic fluorine compound such as Si (CH ₃ ) ₂ C _n F _{2n + 1} (where n = 1 to 22), or the sixteenth aspect of the present invention A colloidal damper having a long molecular chain, specifically, an organosilicon compound such as Si (CH ₃ ) ₂ C _n H _{2n + 1} (where n = 4 to 22) or Si (CH ₃ ), for example. It is preferable to use an organic fluorine compound such as ₂ C _n F _{2n + 1} (where n = 4 to 22), but in any case, like the colloidal damper of the seventeenth aspect of the present invention, organic silicon Compound or organic Is preferably one made of a fluorine compound, specifically, trimethyl chlorosilane (Si (CH _{3) 3)} or dimethyl octadecyl chlorosilane _{(Si (CH 3) 2 C} 18 H 37) made of such.

  In the present invention, as the porous body, as in the colloidal damper of the eighteenth aspect, silica gel, aerogel, ceramics, porous glass, zeolite, porous PTFE, porous wax, porous polystyrene, alumina and graphite Carbon including charcoal, fullerene and carbon nanotubes can be mentioned as a preferred example. As the porous body made of silica gel, specifically, silica gel used as a material for liquid chromatography can be preferably used. “Sylosphere”, “Super Micro Bead Silica Gel”, “Micro Bead Silica Gel” manufactured by Fuji Silysia Chemical Ltd. "Chromatorex" (all trade names), "God Ball" (trade name) manufactured by Suzuki Oil & Fats Co., Ltd., and the like.

  When silica gel is used as the porous body and a liquid mainly containing water is used as the liquid, specifically, “Chromatorex ODS-BU0020MT” manufactured by Fuji Silysia Chemical Co., Ltd., which has been subjected to a lyophobic treatment with dimethyloctadecylchlorosilane as the usable silica gel. (Product name: d2 = 19.9 μm, d1 = 7.0 nm), “Sylosphere C1504-ODS” (product name: d2 = 4.0 μm, d1 = 8.9 nm), “Sylosphere C1504-DBA4.5” (trade names: d2 = 4.0 μm, d1 = 12.8 nm) manufactured by Fuji Silysia Chemical Co., Ltd., which has been lyophobic treated with trimethylchlorosilane, "God Ball B-6C", "God B-25C "(both trade names) were lyophobized with dimethyloctadecylchlorosilane (d2 = 2.3 μm, d1 = 8.7 nm in the former, d2 = 13.0 μm, d1 = 8.7 nm in the latter) ) And the like.

  In a preferred use example of the colloidal damper, the liquid contained in the sealed space is normally pre-pressurized at a predetermined size. However, if the degree of pressurization is too large, A large amount of liquid flows into the pores in advance, and the dissipated energy efficiency η is deteriorated. In a preferred example, in the case of a piston having a diameter of 10 mm, the liquid is preferably pressurized in advance so that a force of about 7 kN to 10 kN is generated in the piston.

  According to the present invention, it is possible to provide a colloidal damper that can obtain high dissipative energy efficiency η, is excellent in economic efficiency and ease of use, and can be operated normally even at a low temperature.

FIG. 1 is an explanatory diagram of a preferred example of an embodiment of the present invention. FIG. 2 is a cross-sectional explanatory view of the substantially spherical granular material of the example shown in FIG. FIG. 3 is an operation explanatory diagram of the example shown in FIG. FIG. 4 is an explanatory diagram of measurement results of the antifreezing agent (ethanol, ethylene glycol, propylene glycol, or glycerin) mixing rate and the liquid freezing temperature. FIG. 5 is an explanatory diagram showing the relationship between the stroke and pressure for ethanol. FIG. 6 is an explanatory diagram showing the relationship between stroke and pressure for ethylene glycol. FIG. 7 is an explanatory diagram showing the relationship between the stroke and pressure for glycerin.

  Next, the present invention and its embodiments will be described in more detail with reference to the examples shown in the drawings. The present invention is not limited to this example.

  1 and 2, the colloidal damper 1 of this example forms a sealed space 3 in the container 2 in cooperation with the container 2 and the container 2, and guides and supports the container 2 so as to reciprocate in the axial direction X. Piston 4, a porous body 6 accommodated in the sealed space 3 and having a large number of pores 5, and a porous body 6 mixedly accommodated in the sealed space 3 and pores at reduced pressure The piston rod which flows out from the liquid 5 and flows into the pore 5 in the pressure increase and the reciprocating force F in the axial direction X to be attenuated is transmitted to the liquid 7 through the piston 4 to pressurize the liquid 7 8, where the surface 9 defining the pores 5 of the porous body 6 and the outer surface 10 of the porous body 6, that is, the surface 9 defining the pores 5, All outer surfaces are lyophobic with respect to the liquid 7.

  The container 2 includes a cylinder-shaped main body 16 integrally having a disk-shaped bottom portion 15 and other than the main body 16 by screws, pins or the like so as to close the other end of the main body 16 closed at one end by the bottom portion 15. And a disc-shaped lid 17 fixed to the end. A through hole 18 is formed in the lid body 17. The piston 4 includes a seal ring 19. The seal ring 19 seals the sealed space 3 and contacts the inner peripheral surface of the main body 16 so as to be slidable in the axial direction X. The piston rod 8 is fixed to the piston 4 at one end and extends outside the container 2 through the lid body 17 so as to be slidable in the axial direction X.

  The porous body 6 is composed of a plurality of substantially spherical particles 25 accommodated in the sealed space 3 in this example. Each substantially spherical particle 25 is composed of silica gel and includes a plurality of substantially spherical particles 25. The pore 5 has a hollow portion 26 at substantially the center, and the pore 5 opens to the hollow portion 26 at one end, opens to the outside of the substantially spherical granular body 25 at the other end, and radiates from the hollow portion 26. The plurality of pores 5 of the porous body 6 are constituted by the plurality of pores 5.

The outer surface 10 of each of a large number of substantially spherical particles 25 and the surface 9 of the pores 5 constituting the porous body 6 are organosilicon which is a lyophobic substance with respect to the liquid 7 and has a linear molecular chain. A compound (for example, Si (CH ₃ ) ₂ C _n H _{2n + 1} (where n = 1 to 22)) or an organic fluorine compound (for example, Si (CH ₃ ) ₂ C _n F _{2n + 1} (where n = 1 to 22)), Alternatively, an organic silicon compound (eg, Si (CH ₃ ) ₂ C _n H _{2n + 1} (where n = 4 to 22)) or an organic fluorine compound (eg, Si (CH ₃ ) ₂ C _n F _{2n + 1} ( However, when n = 4 to 22)) and the average diameter of the pores 5 is d1, the substantially spherical granular material 25 is not less than 10 times the average particle diameter d1 of the pores 5 and is 10,000 times The average diameter d2 is in the following range. The surface 27 defining the hollow portion 26 of the substantially spherical granular body 25 may also be coated with such a lyophobic substance.

  The liquid 7 is made of water mixed with at least 50% by volume of at least one selected from ethanol, ethylene glycol, propylene glycol and glycerin. When the average free path of the liquid molecule is Lp, the pore 5 The Knudsen number Kn = Lp / (d1 · 1/2) is larger than 0.01 and has an average diameter d1 smaller than 0.1.

The porous body 6 and the liquid 7, the total volume of the pores 5 of the porous body 6 and _{V P,} when the volume of the liquid 7 and _{V L,} the ratio _V P / _{V L} is a 0.2 or higher In this example, it is accommodated in the sealed space 3 so that the ratio V _P / V _L is substantially 1 in a range of 2.5 or less.

  In the above colloidal damper 1, when a force F is applied to the piston rod 8, this force F is applied to the liquid 7 via the piston 4 to pressurize the liquid 7. The piston 4 is moved so as to decrease the volume of the sealed space 3 as shown in FIG. 3 against the surface tension, so that the force F applied to the piston rod 8 is reduced. When it disappears, the liquid 7 that has flowed into the pores 5 against the surface tension flows out of the pores 5 due to the surface tension, so that the piston 4 increases the volume of the sealed space 3 on the contrary. To return to the initial position as shown in FIG. In the colloidal damper 1, since the work energy of the force F is consumed by the inflow of the liquid 7 into the pore 5, the force F that moves the piston rod 8 is attenuated.

  By the way, from the measurement results shown in FIG. 4, the freezing temperature of the liquid 7 composed of water mixed with 50% by volume of ethanol, ethylene glycol, propylene glycol or glycerin is −30 ° C. or less (about −32 ° C. for ethanol and propylene glycol). As a result, the freezing temperature of the liquid 7 composed of water mixed with 40% by volume of ethanol, ethylene glycol, propylene glycol or glycerin is about −20 ° C. It has been found that such a colloidal damper 1 can be operated even at low temperatures.

  Moreover, as an Example, each liquid 7 which consists of water which mixed silica with 0 volume%, 25 volume%, and 50 volume% using ethanol as a porous body, 0 volume%, 10 volume%, 20 volume of ethylene glycol %, 30%, 40% and 50% by volume of each liquid 7 mixed with water, and 0%, 25% by volume and 50% by volume of each liquid 7 mixed with 50% by volume of water 7 sealed space 3 respectively. The colloidal damper 1 accommodated in the liquid 7 is prepared, and the pressure (internal pressure) P of the liquid 7 when the piston 4 is moved by the stroke S (mm) at an ambient temperature of 20 ° C. in the colloidal damper 1 accommodating these various liquids 7. Was measured.

  FIG. 5 shows the case of ethanol, FIG. 6 shows the case of ethylene glycol, and FIG. 7 shows the case of glycerin.

  As shown in FIG. 5, in the case of ethanol, the dissipated energy (corresponding to the area surrounded by the stroke S-pressure P curve) is greatly reduced as the mixing ratio is increased compared to the other two. In the case of glycerin, the dissipated energy hardly changes even when the mixing ratio is increased as compared with the other two, and in the case of ethylene glycol, the mixing ratio and the dissipation are as shown in FIG. It turned out to be an intermediate value for the other two in relation to energy.

  As a result, in the case of ethanol, the surface tension σ of the liquid 7 is greatly decreased as the mixing ratio is increased. In the case of glycerin, the surface tension σ of the liquid 7 is hardly increased even if the mixing ratio is increased. This is thought to be due to no change.

  As described above, according to the colloidal damper 1, since the liquid 7 is composed of water mixed with at least 50% by volume of at least one selected from ethanol, ethylene glycol, propylene glycol and glycerin, ethanol, ethylene glycol, At least one selected from propylene glycol and glycerin serves as an antifreeze for water, and thus can operate normally even at low temperatures, and is economical and easy to use because water is mainly used as liquid 7. In addition, since the surface tension of water can be mainly used, high energy dissipation efficiency η can be obtained.

  The sealed space 3 may contain one or a plurality of porous bodies 6 made up of a plurality of substantially spherical granular bodies 25, and The colloidal damper 1 may be configured by mixing one or more and a plurality of dispersed substantially spherical particles 25 in the sealed space 3.

DESCRIPTION OF SYMBOLS 1 Colloidal damper 2 Container 3 Sealed space 4 Piston 5 Pore 6 Porous body 7 Liquid

Claims (18)

  A container, a piston that cooperates with the container to form a sealed space in the container and is guided and supported so as to be reciprocally movable in the container, and a porous body that is accommodated in the sealed space and has a large number of pores And a liquid that flows in the pores of the porous body in a reduced pressure while being contained in the sealed space together with the porous body, and that flows into the pores of the porous body in a pressure increase, The liquid is a colloidal damper made of water mixed with at least 50% by volume of at least one selected from ethanol, ethylene glycol, propylene glycol and glycerin.   The colloidal damper according to claim 1, wherein the liquid is an aqueous solution containing at least 40% by volume of at least one selected from ethanol, ethylene glycol, propylene glycol and glycerin. Surfaces defining pores of the porous body has a lyophobic to the liquid, and the porous body and liquid, the pore volume of the porous body and V _P, a volume of liquid V If _{L, the} colloidal damper according to claim 1 or 2 the ratio V _{P /} V _L are accommodated in the closed space with the range a to 2.5 or less than 0.2. The colloidal damper according to claim 3, wherein the ratio V _P / V _L is in a range of 0.35 or more and 1.5 or less. The colloidal damper according to claim 3, wherein the ratio V _P / V _L is substantially 1.   The colloidal according to any one of claims 1 to 5, wherein the porous body is formed of a substantially spherical granular material having an average diameter d2 that is 10 times or more and 10,000 times or less the average diameter d1 of the pores. damper.   The colloidal according to any one of claims 1 to 5, wherein the porous body is formed of a substantially spherical granular material having an average diameter d2 that is not less than 100 times and not more than 5000 times the average diameter d1 of the pores. damper.   The colloidal damper according to any one of claims 1 to 7, wherein the porous body is a lump of a plurality of substantially spherical granular bodies, and at least one lump is accommodated in the sealed space.   The colloidal damper according to any one of claims 1 to 8, wherein the porous body is composed of a plurality of substantially spherical granular bodies dispersedly accommodated in a sealed space.   The porous body is composed of a substantially spherical granular body having a hollow portion, and the pores are open to the central hollow portion at one end of the substantially spherical granular body having the hollow portion and open to the outside of the substantially spherical granular body at the other end. The colloidal damper according to any one of claims 1 to 9.   The colloidal damper according to claim 10, wherein the pores of the porous body extend in a radial direction from the hollow portion.   The pores of the porous body have an average diameter d1 in which the Knudsen number Kn = Lp / (d1 · 1/2) is larger than 0.01 and smaller than 0.1, where Lp is the mean free path of liquid molecules. The colloidal damper according to any one of claims 1 to 11, comprising:   The colloidal damper according to any one of claims 1 to 12, wherein a surface defining pores of the porous body is coated with a lyophobic substance.   The colloidal damper according to any one of claims 1 to 12, wherein the entire surface of the porous body including the surface of the pores is coated with a lyophobic substance.   The colloidal damper according to claim 13 or 14, wherein the lyophobic substance is a substance having a linear molecular chain.   The colloidal damper according to any one of claims 13 to 15, wherein the lyophobic substance is made of a substance having a long molecular chain.   The colloidal damper according to any one of claims 13 to 16, wherein the lyophobic substance is composed of an organosilicon compound or an organofluorine compound.   The porous body is made of at least one of silica gel, aerogel, ceramics, porous glass, zeolite, porous PTFE, porous wax, porous polystyrene, alumina, and carbon including graphite, charcoal, fullerene, and carbon nanotube. The colloidal damper according to any one of claims 1 to 17.

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