JP2001065196A - Sliding base-isolating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably display base isolating effects at the initial stage of the occurrence of an earthquake, to provide superior durability by preventing sand, dust, etc., from being caught in the sliding surface of a sliding bearing, and to stably display a low coefficient of friction for a long period. SOLUTION: This device is provided with a sliding bearing 3 to be arranged between a lower building frame 1 and upper building frame 2. In the sliding bearing 3, a smooth plate 4 and sliding material 5 are arranged with their sliding surfaces in contact with each other. A recessed part is provided for the sliding surface of the sliding material 5. A solid lubricant 9 formed of a mixture containing lubricating grease and a resin based on ultrahigh-molecular- weight polyolefin is incorporated in the recessed part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sliding seismic isolation device, and more particularly to a building structure from a high-rise structure such as a building or a tower to a low-rise structure such as a detached house, a civil structure from a bridge such as a road or a railway, It relates to a seismic isolation device that supports precision equipment and reduces external forces.

[0002]

BACKGROUND OF THE INVENTION Seismic isolation is the reduction of the seismic force on a building in some way. The "base insulation type", which reduces the input of earthquakes into a building by inserting some device between the foundation and the building, is the mainstream of seismic isolation devices or seismic isolation methods. For example, there is a slip seismic isolation device using a combination of a slide bearing and a horizontal spring. In this method, a sliding material such as a resin sliding plate is attached to a basic footing of a sliding bearing, and the plate and a metal plate attached to a column are allowed to slide. In other words, the building slides against horizontal vibrations of the ground due to the earthquake, so that a force greater than the frictional force acting on the slip surface acts on the building.The horizontal spring moves to prevent the building from moving significantly. Is regulated. Therefore, the smaller the friction coefficient of the slip material is, the greater the seismic isolation effect is, and a stable and small friction coefficient is required to surely exhibit the seismic isolation effect.

For this reason, a fluorine-based material such as a tetrafluoroethylene (hereinafter abbreviated as PTFE) resin having a small friction coefficient is often used as a sliding material having a uniformly continuous plane. Further, there is known a sliding bearing in which a concave portion is provided on the surface of a sliding material, a gel lubricant is sealed in the concave portion, and the lubricant is applied around the concave portion (Japanese Utility Model Publication No. 6-40243).

[0004]

However, in the case of a sliding bearing using a sliding material having a uniformly continuous plane, although the manufacturing cost is low, the vertical load per unit area is small. Due to the mechanical characteristics of PTFE, there is a problem that the coefficient of friction increases, and wear powder generated by friction adheres to the sliding surface and hinders sliding.

[0005] Further, a sliding bearing formed by providing a concave portion on the sliding surface, enclosing lubricating grease in the concave portion, and applying the lubricating grease around the concave portion has a low coefficient of friction at the time of start-up and sliding, and has a concave portion. Although the abrasion powder is discharged and the low friction coefficient is stabilized, the lubricating grease sealed in the concave part separates into base oil and tonicifier over time, and releases oil.
After a long period of time, only the tonicity agent remains in the concave portions, and there is a problem that a stable low coefficient of friction cannot be obtained for a long period of time.

[0006] Further, in any of the sliding bearing having a uniformly continuous flat surface and the sliding bearing having a concave portion, when the sliding bearing is incorporated in the sliding seismic isolation device, dust and the like easily adhere to the lubricating grease. Therefore, there is a problem that the mating material is worn, and then the PTFE is worn, and as a result, the friction coefficient is increased. The problem is that during an earthquake, sand and dust adhering to the outer periphery of the solid lubricant such as PTFE on the sliding surface of the sliding bearing bite into the mating material such as a stainless steel plate with a surface finish, causing the stainless steel plate to be damaged. This also occurs when the sliding bearing wears and the coefficient of friction increases. Further, lubricating grease has problems that it has an unpleasant odor and is difficult to handle.

SUMMARY OF THE INVENTION The present invention has been made to address such a problem, and has a stable seismic isolation effect at the initial stage of an earthquake, and prevents dust and the like from biting into a sliding surface of a sliding bearing. An object of the present invention is to provide a sliding seismic isolation device which is excellent in durability by preventing it and which exhibits a low friction coefficient stably for a long time.

[0008]

SUMMARY OF THE INVENTION The present invention is a slip seismic isolator having a slide bearing disposed between a lower frame and an upper frame. , The sliding material is arranged in contact with each sliding surface,
A concave portion is provided on the sliding surface of the sliding member, and a solid lubricant made of a mixture containing lubricating grease and an ultra-high molecular weight polyolefin resin is incorporated in the concave portion.

Another aspect of the present invention is a slip seismic isolation device including a slip bearing disposed between a lower frame and an upper frame, wherein the slip bearing includes a smooth plate, a slip member, The sliding surfaces are arranged in contact with each other, and a solid lubricant made of a mixture containing a lubricating grease and an ultrahigh molecular weight polyolefin resin is provided on the outer peripheral edge of the sliding surface of the sliding material. It is characterized by the following.

Further, the sliding material is characterized by comprising a tetrafluoroethylene resin composite material.

[0011] Further, the solid lubricant is a lubricating grease.
~ 99% by weight, average molecular weight 1 × 10 ⁶~ 5 × 10⁶Is super
Mix 95 to 1% by weight of high molecular weight polyolefin resin
Gelation of ultra-high molecular weight polyolefin resin
Dispersed and maintained at a temperature above the temperature and below the drop point of the lubricating grease
It is characterized by having been made. Where the superpolymer
The gel point of a polyolefin resin is
Mixes when the mixture with grease is stirred while raising the temperature
The temperature at which the viscosity of an object rises sharply. In addition,
Shaped lubricating material is lubricating grease and ultra high molecular weight polyolefin
Lubricant grease is added to the entire mixture with the base resin.
Add 1-50% by weight of base oil leaching inhibitor
Above the gel point of molecular weight polyolefin resin and lubricated
Dispersed and maintained at a temperature below the grease drop point
It is characterized by the following.

A recess is provided on the sliding surface of the sliding member, and a solid lubricant made of a mixture containing a lubricating grease and an ultra-high molecular weight polyolefin resin is incorporated into the recess, so that deterioration of the solid lubricant over time is small. A low coefficient of friction can be stably maintained for a long time. In addition, minute dust and dirt attached to the sliding bearings and abrasion powder generated by sliding accumulate in the recess of the sliding surface, and hard sand and dust are buried in the solid lubricant, so they do not come out on the sliding surface and are not exempt. Does not hinder sliding during an earthquake.

Further, by disposing a solid lubricant comprising a mixture containing a lubricating grease and an ultra-high molecular weight polyolefin resin on the outer peripheral edge of the sliding surface of the sliding material, it is possible to attach the sliding lubricant when the sliding bearing is assembled or to adhere to the sliding bearing over time. It is possible to prevent the dust and the like from getting caught between the counterpart material and the like.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An example of a slip seismic isolation device according to the present invention will be described with reference to FIG. FIG. 1 is a cross-sectional view of a slip bearing portion of the slip seismic isolation device. Lower frame 1 and upper frame 2
A sliding bearing 3 is disposed between the two. Slip bearing 3
Is composed of a smooth plate 4 and a sliding member 5 whose sliding surfaces are in contact with each other. Reference numeral 6 denotes a member that elastically deforms up to the maximum static frictional force of a sliding material such as laminated rubber, and 7 denotes an intermediate plate, which are provided as necessary.

The smooth plate 4 constituting the slide bearing 3 can be used as long as it is flat and hard without protrusions on the surface. For example, a metal plate, a ceramic plate, a hard resin plate such as a polyimide resin, and a PT hardened by blending a filler.
Any flat plate made of a FE-based resin can be used. Among these, a metal plate is preferable, and a stainless steel plate is most preferable, particularly in consideration of rust prevention, production cost, workability, and the like.

The smooth surface of the smooth plate has a surface roughness (Ry) of preferably 0.05 to 0.50 μm, more preferably 0.10 to 0.20 μm. Here, the surface roughness (Ry) refers to a value defined in JIS B0601. By setting the surface roughness (Ry) within the above range, an appropriate amount of the lubricant can be held over the entire sliding surface, and the initial slip property is improved. When the surface roughness (Ry) is less than 0.05 μm, the production cost increases and maintenance becomes difficult, and when the surface roughness (Ry) exceeds 0.50 μm, the wear characteristics of the sliding material are impaired.

The sliding surface of the sliding member 5 is formed with a concave portion into which a solid lubricant can be incorporated. An example of the shape of the recess is shown in FIGS. 2 and 3 are plan views of the sliding member 5 in which the solid lubricant is incorporated, as viewed from the sliding surface 8. For example, an annular concave groove 5a concentrically arranged as shown in FIG. 2 or a number of small circular concave holes 5b as shown in FIG.
A solid lubricant 9 made of a mixture containing lubricating grease and an ultrahigh molecular weight polyolefin resin is incorporated in these concave grooves 5a or concave holes 5b.

By forming a recess in the sliding surface 8, the sliding surface is no longer a uniform continuous plane as in the prior art, so that the vertical load per unit area increases and the friction coefficient decreases. Further, the sliding member 5 having a low friction coefficient can be constituted by the solid lubricant 9 incorporated in the concave portion provided on the sliding surface. Further, the wear powder generated due to the sliding of the sliding member 5 is held in the concave portion without adhering to the sliding member 5, and the sliding is not hindered by the wear powder.

Another example of the sliding seismic isolation device of the present invention will be described with reference to FIGS. FIG. 4 is a cross-sectional view of a slip bearing portion in another slip seismic isolation device, and FIG. 5 is a perspective view of a solid lubricant 9. In the slip seismic isolation device in FIG. 4, a ring-shaped notch 5c is provided on the outer peripheral edge of the sliding surface of the slip member 5, and the notch 5c is made of a mixture containing lubricating grease and an ultrahigh molecular weight polyolefin resin. Solid lubricant 9 is disposed. In addition, a recess may be provided on the sliding surface 8 together with the notch 5c. By arranging the solid lubricant 9 in a ring shape on the outer peripheral edge of the sliding surface, dust and the like deposited on the smooth plate 4 do not bite into the sliding bearing during sliding, and the dust and the like are deposited on the solid lubricant 9. It is buried and held, and the sliding member 5 is not damaged.

The sliding member 5 is formed of a PTFE-based resin composite. The PTFE-based resin composite material is obtained by blending at least one compounding agent selected from a fibrous compounding agent, a resin powder, and an inorganic compound powder with a PTFE-based resin.
PTFE resins include PTFE resin and modified PTFE.
Resin can be mentioned. The PTFE resin is a homopolymer of ethylene tetrafluoride, which is softened at 310 to 390 ° C. and can be subjected to compression molding and extrusion molding, but cannot be subjected to ordinary injection molding. Commercially available products include Algoflon (Audimont), Teflon (DuPont),
Fluon (manufactured by ICI), polyflon (manufactured by Daikin Industries, Ltd.) and the like can be mentioned.

In the modified PTFE resin, the tetrafluoroethylene unit and the fluorine of the tetrafluoroethylene are converted to another organic group (-X).
And a substituted tetrafluoroethylene unit. The general formula is shown in Chemical formula 1. The organic group (-X) is not particularly limited, but is preferably a perfluoroalkyl ether group or a fluoroalkyl group.

Embedded image Commercially available modified PTFE resins include Teflon TG70
J (manufactured by Du Pont-Mitsui Fluorochemicals), Polyflon M111 (manufactured by Daikin Industries, Ltd.), Hostaflon TFM1
600 (manufactured by Hoechst) and the like.

The polymerization method of the PTFE resin and the modified PTFE resin is not limited, but the molecular weight of the resin is about 50.
It is preferably from 10 to 10 million, and more preferably from 1 to 7 million. By having a molecular weight in this range, the friction coefficient can be reduced as a sliding material, and mechanical strength such as creep resistance can be maintained.
In particular, when the modified PTFE shown in Chemical Formula 1 is used, the creep resistance is improved and the allowable surface pressure on the slip surface can be allowed up to about 30 MPa. Along with that, the slip surface can be reduced,
This is preferable because the size of the sliding seismic isolation device can be reduced.

Among the compounding agents that can be added to the PTFE-based resin, examples of the fibrous compounding agent include glass fiber, carbon fiber, and whiskers. The carbon fibers may be either pitch-based or bread-based carbon fibers. Commercially available products include Crecamild M101S (manufactured by Kureha Chemical Industry Co., Ltd.) and Donacarbon S241 (manufactured by Osaka Gas Chemicals) as pitch-based carbon fibers, and Vesfight HT as bread-based carbon fibers.
A-CMF0160-0H (manufactured by Toho Rayon Co., Ltd.) and the like.

Other examples of the fibrous compounding agent include various whiskers of short fibers. As a commercial product, Franklin Fiber A is used as calcium sulfate whisker.
-30 (anhydrous salt type), Franklin Fiber H-30
(Hemihydrate salt type) (fiber length 50-60 μm, manufactured by Dainichi Seika Kogyo Co., Ltd.), Tismo N as potassium titanate whisker (fiber length 10-20 μm, manufactured by Otsuka Chemical Co., Ltd.), Thaibreck (fiber length 20 μm And zinc oxide whiskers such as Panatetra (fiber length 2 to 50 μm, manufactured by Matsushita Electric Industrial Co., Ltd.), and magnesium sulfate whisker such as Moss Heidi (fiber length 10 to 30 μm, manufactured by Ube Industries). it can.

Among the compounding agents, the resin powder is preferably a powder that can withstand the PTFE molding temperature of 380 ° C. For example, thermoplastic polyimide resin (manufactured by Mitsui Chemicals), thermosetting polyimide resin (manufactured by Furon, Ube Industries), polyetheretherketone resin (manufactured by Victrex MC), wholly aromatic polyester resin (Sumitomo Chemical) Industrial Co., Ltd.), aramid powder, polyamide-imide resin (Mitsubishi Kasei), mesocarbon beads (Osaka Gas Chemical Co., Ltd.), Bellpearl (Kanebo Co., Ltd.), Univex (Unitika Co., Ltd.), micro carbon beads (Nippon Carbon Co., Ltd.) Manufactured).

Further, examples of the inorganic compound powder include molybdenum disulfide, zinc oxide, titanium oxide, graphite, metal oxide powder, glass beads, and silica powder.

The compounding amount of the compounding agent is preferably 5 to 40 parts by volume based on 100 parts by volume of the PTFE resin. If the amount of the compounding agent exceeds 40 parts by volume, there may be a problem in moldability or damage to the smooth plate. If the amount is less than 5 parts by volume, the reinforcing effect is poor, and sufficient creep resistance and wear resistance cannot be obtained.

A solid lubricant comprising a mixture containing a lubricating grease and an ultrahigh molecular weight polyolefin resin will be described. In the present invention, the lubricating grease refers to a semisolid or solid viscous substance having lubricity at room temperature.
In particular, a semi-solid or solid viscous substance at room temperature comprising a liquid lubricating oil (base oil) and a thickener is preferred for the solid lubricant of the present invention. The solid lubricant can be produced, for example, by the following method. That is, a predetermined amount of lubricating grease and a predetermined amount of an ultra-high molecular weight polyolefin resin are uniformly mixed and poured into a mold having a predetermined shape. It is obtained by dispersing and maintaining at the following temperature and cooling at room temperature. In addition, a mixture of a predetermined amount of lubricating oil and a predetermined amount of a bleeding inhibitor for lubricating oil is uniformly mixed with a predetermined amount of an ultra-high-molecular-weight polyolefin-based resin, and poured into a mold having a predetermined shape to form an ultra-high-molecular-weight polyolefin. It can also be obtained by dispersing and holding at a temperature equal to or higher than the gel point of the system resin and cooling at room temperature.

As the ultrahigh molecular weight polyolefin resin, various resin forms can be used, but it is preferable to use a powdery resin which is easily mixed with lubricating grease or the like. As such an ultrahigh molecular weight polyolefin powder, a powder composed of polyethylene, polypropylene, polybutene, or a copolymer thereof is preferable. Each of these powders may be a single powder or a mixed powder thereof. The molecular weight of the ultra-high molecular weight polyolefin powder has an average molecular weight of 1 × 10
^{It is 6} to 5 × 10 ⁶ . A polyolefin resin having such an average molecular weight is superior to a low molecular weight polyolefin resin in rigidity and oil retention, and hardly flows even when heated to a high temperature.

The mixing ratio of the solid lubricant is determined by
5 to 99% by weight, 9 ultra-high molecular weight polyolefin resin
It is 5 to 1% by weight. The amount of each component depends on the degree of oil release, toughness and hardness required for the solid lubricant. Therefore, the greater the amount of the ultrahigh molecular weight polyolefin resin, the greater the hardness of the gel after being dispersed and maintained at a predetermined temperature. In addition, various organic or inorganic fillers can be blended to increase rigidity while maintaining a high oil content.

The lubricating grease according to the present invention is not particularly limited. The lubricating grease added with soap or non-soap may be lithium soap-diester, lithium soap-polyalphaolefin, lithium soap-dialkyl. Diphenyl ether type, lithium soap-mineral oil type,
Sodium soap-mineral oil system, aluminum soap-mineral oil system,
Lithium soap-diester mineral oil system, non-soap-diester system, non-soap-mineral oil system, non-soap-polyol ester system,
Greases such as lithium soap-polyol ester type are exemplified. Similarly, the lubricating oil is not particularly limited, and lubricating oils of diester type, mineral oil type, diester mineral oil type, polyol ester type, poly-α-olefin type, dialkyldiphenyl ether type and the like can be mentioned. Examples of the non-soap include, for example, urea-based thickeners.

The melting point of the ultra-high molecular weight polyolefin-based resin according to the present invention is not a constant for changes in accordance with the average molecular weight, for example, an average molecular weight by viscosity method is 2 × 10 ⁶
Has a melting point of 136 ° C. Commercial products having the same average molecular weight include Miperon XM-220 (manufactured by Mitsui Chemicals, Inc.).

Therefore, in order to disperse and hold the ultrahigh molecular weight polyolefin resin in the lubricating grease, after mixing both, the lubricating grease was used at a temperature higher than the temperature at which the ultrahigh molecular weight polyolefin resin gelled. In this case, it is preferable to heat at a temperature lower than the drop point, for example, 150 to 200 ° C. Thereby, a solid solid lubricant can be obtained.

The solid lubricant obtained by using the lubricating grease is preferably further mixed with 1 to 50% by weight of a base oil bleeding inhibitor of the lubricating grease. By adding the oozing inhibitor, the oil release rate of oil oozing out from the solid lubricant to the smooth plate can be appropriately suppressed, and an appropriate oozing amount can be obtained. As the oozing inhibitor, a compound such as solid wax or a low-molecular-weight polyolefin containing the same among waxes is used. Examples of the solid wax include vegetable wax such as carnauba wax and candelina wax, animal wax such as beeswax and insect white wax, and petroleum wax such as paraffin wax. The compounding ratio of the leaching inhibitor in the solid lubricant is 1 to 50% by weight. As the blending ratio of the solid wax increases, the oil separation rate can be suppressed, and the speed of oil bleeding decreases. However, if it exceeds 50% by weight, the strength of the solid lubricant decreases, which is not preferable.

[0035]

The sliding seismic isolation device of the present invention has a concave portion provided on the sliding surface of the sliding member, and a solid lubricant made of a mixture containing lubricating grease and an ultrahigh molecular weight polyolefin resin is incorporated in the concave portion. Therefore, the lubricating oil is not separated from the solid lubricating material even after several years, and a slip seismic isolation device having a low-friction coefficient slip bearing excellent in durability can be obtained. Further, the solid lubricating material is capable of burying abrasion powder generated by sliding of the sliding material, minute dust adhering at the time of assembling, and the like. As a result, a sliding seismic isolator having a low-friction coefficient low-friction bearing with excellent durability can be obtained by confining abrasion powder, dust and the like that hinder sliding of the sliding bearing in the recess. Further, since the concave portion is provided on the sliding surface of the sliding member, the vertical load per unit area increases. As a result, the frictional coefficient is reduced together with the lubricating effect of the solid lubricant, and the sliding seismic isolation device having the sliding bearing whose frictional coefficient is reduced not only during startup for a long period of time but also during operation is provided. can get.

According to another slip seismic isolation device of the present invention, a solid lubricant made of a mixture containing lubricating grease and an ultra-high molecular weight polyolefin resin is disposed on the outer peripheral edge of the sliding surface of the sliding material. Foreign matter such as sand and dust adhered to the smooth plate is buried in the solid lubricant without being bitten between the slide bearing and the smooth plate when an earthquake occurs. As a result, a sliding seismic isolation device having a sliding bearing with a low coefficient of friction can be obtained without damaging the sliding surface of the smooth plate and thus preventing the generation of wear powder.

Further, since the slip material is made of a tetrafluoroethylene-based resin composite material, the coefficient of friction as the slip material can be reduced, and mechanical strength such as creep resistance can be maintained. As a result, a miniaturized slip seismic isolation device is obtained.

The solid lubricant is lubricated grease 5 to 9
9 to 9% by weight of ultra-high molecular weight polyolefin resin is mixed with 95 to 1% by weight and dispersed and maintained at a temperature above the gel point of the ultra-high molecular weight polyolefin resin and below the dropping point of lubricating grease. In addition, since 1 to 50% by weight of the exudation inhibitor is added and mixed, a highly durable sliding seismic isolation device which can maintain a low friction coefficient for a long time can be obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a slip bearing portion of a slip seismic isolation device.

FIG. 2 is a plan view of a sliding surface of a sliding member.

FIG. 3 is a plan view of a sliding surface of another sliding member.

FIG. 4 is a cross-sectional view of a slip bearing portion of another slip isolation device.

FIG. 5 is a perspective view of a solid lubricant.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Lower frame 2 Upper frame 3 Slip bearing 4 Smooth plate 5 Slip material 5a Depression groove 5b Depression hole 5c Ring notch 6 Laminated rubber 7 Middle plate 8 Sliding surface of slip material 9 Solid lubricant

Claims (5)

[Claims] 1. A slip seismic isolator comprising a slide bearing disposed between a lower frame and an upper frame, wherein the slip bearing is configured such that a smooth plate and a slip member are mutually connected. The sliding surface of the sliding material is disposed in contact with the sliding surface, a concave portion is provided on the sliding surface of the sliding material, and a solid lubricant made of a mixture containing lubricating grease and an ultrahigh molecular weight polyolefin resin is incorporated in the concave portion. Sliding seismic isolation device characterized by the following. 2. A slip seismic isolation device comprising a slide bearing disposed between a lower frame and an upper frame, wherein the slip bearing is configured such that a smooth plate and a slip member are mutually connected. The sliding surface is disposed in contact with the sliding surface, a solid lubricant comprising a mixture containing a lubricating grease and an ultra-high molecular weight polyolefin resin is disposed on the outer peripheral edge of the sliding surface of the sliding material, Sliding seismic isolation device. 3. The slip-isolation device according to claim 1, wherein the slip member is made of a tetrafluoroethylene-based resin composite material. 4. The lubricating grease according to claim 4, wherein the solid lubricant is
To 99% by weight and 95 to 1% by weight of the ultrahigh molecular weight polyolefin resin having an average molecular weight of 1 × 10 ⁶ to 5 × 10 ⁶ , and at least the gel point of the ultrahigh molecular weight polyolefin resin and The slip seismic isolation device according to claim 1 or 2, wherein the lubricating grease is dispersed and maintained at a temperature equal to or lower than a drop point of the lubricating grease. 5. The lubricant according to claim 1, wherein the solid lubricant further suppresses bleeding of the base oil of the lubricating grease with respect to the entire mixture of the lubricating grease and the ultrahigh molecular weight polyolefin resin.
5. The composition according to claim 4, wherein 0% by weight is added and mixed and dispersed and maintained at a temperature not lower than the gel point of the ultrahigh molecular weight polyolefin resin and not higher than the drop point of the lubricating grease. Slip seismic isolation device.