JP2015057561A - Gas spring type vibration isolation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To substantially resolve minute positional deviation of a load reception member in a horizontal direction with a simple structure, in a gas spring type vibration isolation device using a piston, such as a dome gimbal piston, into which a rolling mechanism is assembled.SOLUTION: A rolling element 39 is attached to an enlarged-diameter part 31b of the upper end of a support rod 31 constituting a piston 12, and a receiving seat 43 receiving a curve surface 41b of the rolling element 39 in a rollable manner is attached to the lower surface of a load disk 29. The rolling element 39 and the receiving seat 43 are surrounded and constrained by a holding jig 45 in a state where the rolling element 39 and the receiving seat 43 are brought into contact with each other in a vertical direction. The holding jig 45 is indirectly or directly fixed to the load disk 29 and the support rod 31.

Description

  The present disclosure relates to a gas spring vibration isolator that elastically supports a supported body with a gas spring.

  Conventionally, as a vibration isolator of this type, a piston in a vibration isolator using a diaphragm-type air spring is incorporated with a gimbal mechanism and a rolling mechanism, and the horizontal displacement between the supported body and the floor surface There is known a device using a piston called a dome gimbal piston, which can obtain a soft spring characteristic in the horizontal direction by converting the oscillating motion into a swinging motion of the piston.

  The schematic configuration of such a vibration isolator is shown in FIGS. As shown in FIG. 12A, the vibration isolator includes a disk-shaped load disk (load receiving member) 101 that receives the load of the supported body, and a piston 103 that is an air spring located below the disk. The piston 103 has a structure in which a bottomed cylindrical piston well 109 extending downward is provided at the bottom of a donut-shaped piston main body 107 whose outer periphery is held by a diaphragm (flexible member) 105. The support rod 111 is inserted into the piston 103 from the upper side of the piston main body 107 into the hollow portion of the piston well 109, and the lower end of the rod 111 is pivotally supported at the bottom of the piston well 109.

  The load disk 101 is supported by the upper end portion of the support rod 111. The upper end portion of the support rod 111 protrudes upward from the upper surface of the piston main body 107 and has a spherical shape (dome shape) in which the diameter of the upper surface of the rod 111 is larger than that of other portions of the rod 111 and the entire upper surface protrudes upward. A rolling element 113 formed on a curved surface is provided. The rolling element 113 is held from the outer peripheral side by a rubber elastic ring 115 for positioning attached to the lower surface of the load disk 101. The support rod 111 swings with respect to the load disk 101 by bringing the curved surface of the rolling element 113 into contact with the lower surface of the load disk 101 so as to freely roll.

  In the vibration isolator using the dome gimbal piston, the load disk 101, the piston 103 and the support rod 111 are integrally supported by the air spring 18 as shown in FIG. An excellent vibration isolation effect is obtained with respect to vibration, and further, the diaphragm 105 holding the piston body 107 is bent so as to swell up and down with the piston body 107 interposed therebetween, so that the piston 103 swings and the rolling element The support rod 111 swings as the 113 rolls on the lower surface of the load disk 101, and an excellent vibration isolation effect is obtained even in the horizontal direction by combining the swing of the piston 103 and the support rod 111. (For example, refer to Patent Document 1).

  As a gas spring type vibration isolator, a device using a piston called a gimbal piston that incorporates a gimbal mechanism in the piston but does not include the rolling mechanism is also known. In this vibration isolator, silicon oil acting as a damper is accommodated in the hollow portion in the piston well, and the lower end side portion of the support rod is immersed in silicon oil to obtain a damping effect on the horizontal vibration in the piston. In addition, it is known that the transmission rate at the time of resonance in which the vibration frequency from the installation surface of the vibration isolation device matches the natural frequency of the vibration isolation device is suppressed (for example, see Patent Document 2).

JP 2007-321932 A JP 2002-310229 A

  In the vibration isolator using the dome gimbal piston described above, the load disk 101 is supported by the curved surface of the rolling element 113 provided at the upper end of the support rod 111. Even if the ring 115 is attached, there is a problem that it is not possible to prevent the occurrence of a minute displacement of the rolling element 113 with respect to the load disk 101 by itself. This will be described in detail below with reference to FIG. FIG. 13 is a schematic diagram illustrating a state in which the air pressure of the air spring of the vibration isolation device is reduced.

  For example, when the air spring is evacuated during maintenance of the vibration isolator, or when the air pressure of the air spring decreases for some reason, as shown in FIG. Is pulled downward by its own weight, the rolling element 113 at the upper end of the rod 111 comes out of the rubber elastic ring 115 and is separated from the lower surface of the load disk 101. Then, even if the air pressure of the air spring subsequently recovers and the piston body 107 rises and returns to the state shown in FIG. 12A again, the contact position of the rolling element 113 with respect to the load disk 101, that is, the rolling Strictly speaking, the support position of the load disk 101 by the child 113 does not return to the original position, and a slight positional deviation occurs in the horizontal direction. As a result, the position of the load disk 101 is slightly shifted in the horizontal direction, which may cause a problem when, for example, a semiconductor manufacturing facility or the like requiring submicron accuracy is mounted.

  Therefore, in order to prevent the rolling element from separating from the lower surface of the load disk, it is conceivable to provide the vibration isolator with a stopper mechanism that restricts excessive lowering of the piston when the air spring air pressure decreases. In this case, the device structure becomes complicated, leading to an increase in cost.

  The present invention has been made in view of such a point, and an object of the present invention is to provide a horizontal structure for a load receiving member in a gas spring type vibration isolator using a piston incorporating a rolling mechanism such as a dome gimbal piston. The purpose is to substantially eliminate the slight positional deviation in the direction with a simple structure.

  In order to achieve the above object, according to the present invention, a mechanism member constituting a rolling mechanism is attached to the load receiving member and the piston, respectively, and both the mechanism members are in contact with each other in the vertical direction. Surrounding and restraining, the holder was fixed to the load receiving member and the piston via a mechanism member or directly.

  Specifically, in the present invention, a load receiving member that receives a load of a supported body is disposed above a case having an opening on the upper surface, and a piston that supports the load receiving member is inserted into the case from the opening. The lower end surface of the piston faces the inside of the case, and the outer periphery of the piston to the periphery of the opening of the case is closed with an annular flexible member to elastically support the load on the supported body. The following solution is taken for a gas spring vibration isolator that constitutes a gas spring to be supported.

  That is, 1st invention is provided with the rolling mechanism which rolls a piston with respect to a load receiving member. The rolling mechanism includes a first mechanism member attached to the load receiving member and a second mechanism member attached to the piston. Of these first mechanism member and second mechanism member, one mechanism member is a rolling element having a convexly protruding curved surface, and the other mechanism member rolls on the curved surface of the rolling element. A receiving seat having a rolling surface that is freely received. The rolling element and the seat are made of rubber that allows the rolling movement of the rolling element by elastic deformation. It is constrained in a state where it is in contact with the direction. In the first invention, the holder is fixed to at least one member of the load receiving member and the first mechanism member and to at least one member of the piston and the second mechanism member. Features.

  According to the first aspect of the invention, the rolling element and the receiving seat are enclosed by the holding tool and restrained in a state where the curved surface and the driven surface are in contact with each other, and the holding tool is attached to the load receiving member and the load receiving member. Since it is fixed to at least one of the attached first mechanism member and at least one of the piston and the second mechanism member attached thereto, the pressure of the gas spring is lowered for some reason. However, even if the piston is pulled downward by its own weight, the positional relationship between the load receiving member and the piston in the vertical direction is maintained by the holder, so the curved surface of the rolling element and the receiving seat that contacts this It is possible to prevent separation from the driven surface. Therefore, it is not necessary to provide the vibration isolator with a stopper mechanism that restricts the excessive lowering of the piston when the air spring air pressure drops, and the displacement between the rolling element and the receiving seat is prevented. The displacement of the load receiving member in the horizontal direction can be substantially eliminated with a simple structure.

  According to a second aspect of the present invention, in the gas spring vibration isolator of the first aspect, the holder is formed in a cylindrical shape into which the rolling element and the receiving seat are fitted, and outwards at both ends in the vertical direction. It has the structure which has the protrusion piece which protruded. In the second invention, the load receiving member is provided with an upper fixing member that presses and fixes the upper protruding piece of the holder against the load receiving member side, and the lower protruding piece of the holding tool is attached to the piston. The lower side fixing member which presses and fixes to the said piston side is attached, It is characterized by the above-mentioned.

  According to the second invention, the protruding pieces provided at the upper and lower ends of the holder are physically fixed to the load receiving member and the piston by pressing the protruding pieces with the upper fixing member and the lower fixing member. By simply attaching the upper fixing member to the load receiving member and the lower fixing member to the piston, the holder can be easily fixed to the load receiving member and the piston.

  According to a third invention, in the gas spring vibration isolator of the second invention, the projecting piece is an annular flange piece extending in the entire circumferential direction of the holder. The third invention is characterized in that the upper fixing member and the lower fixing member press the flange piece over the entire circumference.

  According to the third aspect of the invention, since the annular flange pieces provided at the upper and lower ends of the holder are respectively fixed to the load receiving member and the piston over the entire circumference, the holder is attached to the load receiving member and the piston. The positional relationship in the vertical direction between the load receiving member and the piston can be reliably maintained by the holder.

  According to a fourth aspect of the present invention, in the gas spring vibration isolator of the first aspect, the holder is fixed by being vulcanized and bonded to the rolling element and the receiving seat.

  According to the fourth aspect of the invention, since the holder is firmly fixed to the rolling element and the receiving seat by vulcanization adhesion, the positional relationship between the load receiving member and the piston in the vertical direction is reliably maintained by the holder. can do. Further, according to the fourth aspect of the present invention, since the rotator, the receiving seat, and the holder are vulcanized and bonded, the stress generated in the holder due to the rolling of the rotator can be reduced. Since it acts as a damper that suppresses movement, horizontal vibration generated in the piston is attenuated. As a result, a damping effect can be obtained with respect to vibration in the horizontal direction even if oil for vibration damping such as silicon oil is not accommodated in the hollow portion in the piston as in Patent Document 2. In addition, it is possible to easily change the damping characteristics against the horizontal vibration in the piston of the gas spring by simply replacing the holder with a different mechanical property (such as hardness) together with the rolling element and the receiving seat.

  According to a fifth aspect of the present invention, in the gas spring type vibration damping device according to any one of the first to fourth aspects of the present invention, a concave portion that is recessed upward is formed on the lower surface of the load receiving member. The recessed portion has an inner peripheral surface that surrounds the internal space of the recessed portion. The fifth invention is characterized in that the holder is inserted into the recessed portion with the outer peripheral surface in contact with the inner peripheral surface of the recessed portion.

  According to the fifth aspect of the present invention, it is possible to suppress the occurrence of an extra space between the load receiving member and the piston, and to reduce the height of the vibration isolation device accordingly. As a result, the vibration isolation device can be made compact. In addition, the holder inserted into the recessed portion is in contact with the inner peripheral surface of the recessed portion, thereby exhibiting a higher damper effect and effectively attenuating horizontal vibration generated in the piston. it can.

  According to a sixth aspect of the present invention, in the gas spring type vibration damping device according to any one of the first to fifth aspects, the rolling element has a fastening piece projecting outward at a lower end portion, and the fastening piece on the piston. It has the structure attached by fastening with bolts. The sixth invention is characterized in that a through hole for removing the bolt is formed in a portion of the load receiving member corresponding to the upper side of the bolt.

  According to the sixth aspect of the present invention, the bolts fastening the fastening pieces of the rolling elements are loosened with a tool through the through holes formed in the load receiving member, so that the rolling elements, the receiving seats, and the holders are formed. The moving part can be detached from the piston of the gas spring together with the load receiving member, and the rolling part can be easily replaced.

  According to the present invention, in the gas spring type vibration isolator using the piston incorporating the rolling mechanism, the curved surface of the rolling element constituting the rolling mechanism and the driven surface of the receiving seat abutting on the curved surface are separated from each other. Can be prevented, and the slight displacement of the load receiving member in the horizontal direction can be substantially eliminated with a simple structure.

FIG. 1 is a perspective view showing the overall configuration of a precision vibration isolation table according to Embodiment 1 of the present invention. FIG. 2 is a perspective view of the isolator (vibration isolation device) according to Embodiment 1 of the present invention. 3 is a longitudinal sectional view of the isolator taken along line III-III in FIG. FIG. 4 is an exploded perspective view showing a configuration of a piston used in the isolator according to Embodiment 1 of the present invention and a mounting structure for the case. Fig.5 (a) is a perspective view of the rolling component used for the isolator which concerns on Embodiment 1 of this invention, FIG.5 (b) is a rolling component in the Vb-Vb line | wire of Fig.5 (a). It is a longitudinal cross-sectional view. 6 (a) and 6 (b) are process diagrams showing the replacement work of the rolling parts according to the first embodiment of the present invention. FIG. 7 is a view corresponding to FIG. 3 illustrating an isolator according to Embodiment 2 of the present invention. FIG. 8 is an exploded perspective view showing a configuration of a piston used in an isolator according to Embodiment 2 of the present invention and a structure for mounting the case. Fig.9 (a) is a perspective view of the rolling component used for the isolator which concerns on Embodiment 2 of this invention, FIG.9 (b) is the rolling component in the IXb-IXb line | wire of Fig.9 (a). It is a longitudinal cross-sectional view. FIG. 10 is a top view of an isolator according to Embodiment 2 of the present invention. FIGS. 11A and 11B are process diagrams showing the replacement work of the rolling parts according to the second embodiment of the present invention. FIGS. 12A and 12B are schematic cross-sectional views of a conventional gas spring vibration isolator using a dome gimbal piston. FIG. 13 is a schematic cross-sectional view showing a state in which the air pressure of the air spring is reduced in a conventional gas spring vibration isolator.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments according to the present invention will be described in detail with reference to the drawings. The following embodiments are essentially preferable examples, and are not intended to limit the scope of the present invention, its application, or its use.

Embodiment 1 of the Invention
In the first embodiment, a gas spring type vibration isolator according to the present invention will be described with an example of a precision vibration isolation table using a plurality of isolators as isolators.

-Overall configuration-
FIG. 1 is a perspective view showing the overall configuration of the precision vibration isolation table A according to the first embodiment. This precision vibration isolation table A is equipped with, for example, precision devices such as a semiconductor inspection device, an electron microscope, and an optical measurement device (not shown), and these devices are installed in a state of being almost insulated from vibration from the floor surface. Is. As shown in FIG. 1, the schematic structure of the precision vibration isolation table A includes a lower structure portion 1 installed on a floor surface, and gas spring type respectively disposed at four corners of the upper surface of the lower structure portion 1. It consists of an isolator 2 which is a vibration isolator and a mounting plate 3 mounted on the top of these four isolators 2.

  The lower structure portion 1 is a structure in which structural members of a steel square pipe are assembled so as to have a substantially rectangular parallelepiped shape. The lower structure portion 1 is horizontally oriented so that four leg portions 4 extending in the vertical direction and two adjacent leg portions 4 of the four leg portions 4 are connected at the lower end side. And the upper beam part 6 which surrounds the outer periphery on the upper end side of the four leg parts 4 and is arranged in a substantially rectangular frame shape in plan view.

  The inner surface of the upper beam portion 6 is joined to the outer surface of each leg portion 4, and the upper surface of the upper beam portion 6 is positioned on the same plane as the upper end surface of each leg portion 4. Further, a horizontal plate 7 is disposed from the upper end surface of each leg portion 4 to the upper surface of the upper beam portion 6 surrounding the outside. The isolator 2 is disposed on each of these horizontal plates 7. In addition, two moving casters 8 are disposed on the lower surfaces of the two lower beam portions 5 extending in the longitudinal direction of the lower structure portion 1, and heights are provided on the lower end surfaces of the leg portions 4. An adjustment leveler 9 is provided.

-Configuration of isolator-
FIG. 2 is a perspective view of the isolator 2. 3 is a longitudinal sectional view of the isolator 2 taken along the line III-III in FIG. This isolator 2 basically has the same configuration as that of the conventional example (Patent Document 1), and incorporates a gimbal mechanism and a rolling mechanism into the piston 12 of the diaphragm-type air spring 18 in the vertical direction. In addition to the original characteristic of the air spring 18 that is soft, a very soft characteristic can also be obtained in the horizontal direction.

  Specifically, as shown in FIGS. 2 and 3, the isolator 2 is a load that receives a load of a mounting plate 3 (indicated by a two-dot chain line in FIG. 2) that is a supported body and a precision device mounted thereon. A load disk 29 as a receiving member is disposed above a rectangular box-shaped case 11 having an opening 11a on the upper surface, and a piston 12 supporting the load disk 29 is inserted into the case 11 from the opening 11a. A structure in which the lower surface of the piston 12 faces the inside of the case 11 and the outer periphery of the piston 12 to the periphery of the opening 11a of the case 11 is closed by an annular diaphragm 15 that is a flexible member.

  The case 11 is fixed to the upper surface of the horizontal plate 7, and although not shown in detail, a steel bottom plate is joined to the lower end of a square columnar cylindrical wall portion made of a steel thick plate, while the peripheral wall Similarly, the top plate of the case 11 is joined to the upper end of the part. An opening 11a is formed in a circular shape substantially at the center of the top plate. The piston 12 is inserted into the case 11 through the opening 11a of the top plate.

  FIG. 4 is an exploded perspective view showing the configuration of the piston 12 and the mounting structure for the case 11. As shown in FIGS. 3 and 4, the piston 12 includes a donut-shaped piston main body 13 having a circular center hole 14 penetrating in the vertical direction, and extends downward from the piston main body 13 and the center hole 14 of the piston main body 13. A bottomed cylindrical piston well 23 provided with a hollow portion 24 that communicates with the piston body 23, and a support rod 31 having a cylindrical main body inserted into the hollow portion 24 of the piston well 23 through the center hole 14 of the piston main body 13. Prepare.

  The piston body 13 is a member made of an aluminum alloy, and is held by the diaphragm 15 so as to be movable up and down while being inserted into the opening 11 a of the case 11. The diaphragm 15 covers the lower end surface of the piston main body 13 from the outer periphery of the piston well 23 and closes the periphery of the opening 11 a on the upper surface of the case 11. That is, the opening 11 a on the upper surface of the case 11 is closed by the piston main body 13 and the diaphragm 15. As a result, an air chamber 17 facing the lower surface of the piston main body 13 is defined inside the case 11, and the lower surface of the piston main body 13 receives air pressure in the chamber, thereby mainly supporting a vertical load. An air spring 18 is configured.

  The diaphragm 15 is formed of a rubber elastic film in which, for example, a woven fabric such as polyester fiber is embedded as a reinforcing material, and is formed in a substantially dish shape in which a part on the outer peripheral side is bent upward to constitute a convex part of a circular frame shape. Has been. Specifically, the diaphragm 15 includes an inner peripheral portion 15a bonded to the lower end surface of the piston body 13, and an annular roll that is curved so as to protrude upward continuously from the outer peripheral side of the inner peripheral portion 15a. It is comprised by the part 15b and the outer periphery flange part 15c continuously provided in the collar shape continuously on the outer peripheral side of this annular roll part 15b.

  The inner peripheral portion 15 a of the diaphragm 15 is pressure-bonded to the piston main body 13 with a washer 19 from below. Further, the outer peripheral flange portion 15 c of the diaphragm 15 is bonded to the peripheral portion of the opening 11 a on the upper surface of the case 11. On the upper side of the peripheral portion of the opening portion 11 a of the case 11, a fastening ring 21 is attached by being fastened to the top plate of the case 11 with bolts 22. The outer peripheral portion of the diaphragm 15 is sandwiched between the fastening ring 21 and the top plate of the case 11. The annular roll portion 15 b of the diaphragm 15 is inserted between the main body 13 and the fastening ring 21 on the outer periphery of the piston main body 13.

  The diaphragm 15 arranged in this way is flexible with respect to the displacement of the piston body 13 in the vertical direction by bending the annular roll portion 15b so as to wave up and down between the piston body 13 and the fastening ring 21. Further, both side portions sandwiching the piston main body 13 of the annular roll portion 15b are bent in opposite directions in the vertical direction so that the piston main body 13 can be easily swung around the horizontal axis. It has become. On the other hand, the diaphragm 15 has very little flexibility with respect to the displacement of the piston body 13 in the horizontal direction, so that the piston body 13 hardly displaces in the horizontal direction.

  The center hole 14 of the piston body 13 has a stepped shape with a reduced diameter at the lower end. That is, the lower end portion of the center hole 14 constitutes a small diameter portion 14a formed with a relatively small diameter, and the other upper portion constitutes a large diameter portion 14b formed with a relatively large diameter. . An annular bottom surface portion 13 a is formed in the center hole 14 of the piston body 13. The piston well 23 is attached to the piston body 13 by screwing the upper end portion into the small diameter portion 14a of the center hole 14 from below.

  The upper end portion of the piston well 23 constitutes a reduced diameter portion 23a that is slightly reduced in diameter than the other portions. A stepped portion 23 b that supports the inner peripheral edge of the washer 19 is formed at the lower end of the reduced diameter portion 23 a of the piston well 23. The reduced diameter portion 23 a of the piston well 23 is formed longer than the small diameter portion 14 a of the center hole 14 of the piston body 13. A male screw is cut on the outer peripheral surface of the reduced diameter portion 23 a, while a female screw is cut on the inner peripheral surface of the small diameter portion 14 a of the center hole 14. The piston well 23 is screwed into the female hole in the small diameter portion 14a by screwing the male screw of the reduced diameter portion 23a into the central hole 14, and the large diameter of the central hole 14 in the reduced diameter portion 23a. The washer 19 is attached to the main body 13 in a state where the washer 19 is pressed against the piston main body 13 side by the stepped portion 23b by fastening the portion protruding to the portion 14b with the bearing nut 25.

  On the bottom surface of the hollow portion 24 of the piston well 23, a steel well slug 26 having a slightly smaller diameter and a thick disk shape than the bottom surface is provided. The well slug 26 is fastened to the bottom wall of the piston well 23 with a bolt 27 from below, and constitutes the bottom of the piston well 23. The upper surface of the well slug 26 is subjected to a quenching process for increasing the surface hardness.

  The support rod 31 extends in the vertical direction through the hollow portion 24 of the piston well 23, and the lower end portion thereof is pivotally supported by the bottom portion of the piston well 23, that is, the well slug 26. A reduced diameter portion 31 a having a smaller diameter than the other portions is formed at the lower end portion of the support rod 31. A concave portion 32 that opens downward is provided at the distal end surface of the reduced diameter portion 31 a, that is, the lower end portion of the support rod 31. A steel ball 33 is accommodated in the recess 32. The lower portion of the steel ball 33 forms a spherical protruding portion that protrudes downward from the concave portion 32, and is in contact with the upper surface of the well slug 26 so as to be able to roll.

  A rubber holding member 35 mainly composed of a rubber material with little outgas and suitable for use in a clean room, for example, fluorine rubber or chloroprene rubber, is provided on the bottom side of the hollow portion 24 of the piston well 23. Yes. The holding member 35 covers the steel ball 33 from the outer peripheral surface of the reduced diameter portion 31 a of the support rod 31 and further covers the entire side peripheral surface from the upper surface of the well slug 26, and the reduced diameter portion 31 a, the steel ball 33 and the well slug 26. They are connected by vulcanizing and bonding together.

  Further, the outer peripheral side of the holding member 35 gradually increases in diameter downward from the upper end of the reduced diameter portion 31 a of the support rod 31, and extends substantially downward in close contact with the inner peripheral surface of the piston well 23. Is formed. On the outer peripheral surface of the holding member 35, an annular ring extending over the entire circumference in the horizontal direction at a position near the lower end of the reduced diameter portion 31 a of the support rod 31, specifically, at a side position of the protruding portion formed by the steel ball 33. A linear recess 35a is formed. As a result, the holding member 35 is easily bent to bend and deform in all horizontal directions.

  An enlarged diameter portion 31b having a larger diameter than that of the other portions is provided at the upper end portion of the support rod 31. The enlarged diameter portion 31 b of the support rod 31 protrudes upward from the center hole 14 of the piston body 13. The upper surface of the enlarged diameter portion 31b is a flat surface as a whole, and is an attachment surface to which a rolling component 37 described later is attached. The support rod 31 supports the load disk 29 that receives the load of the mounting plate 3 as a supported body and the precision equipment mounted thereon from above via the rolling component 37.

  The load disk 29 is disposed above the piston body 13 at a position spaced apart via a lowered position restriction plate 51. The lowered position restricting plate 51 is a plate-like member that receives the load disk 29 that is lowered when the air pressure in the air chamber 17 is lowered and restricts further downward movement, and is placed on the four corners of the case 11. The block 53 is fastened to the case 11 by fastening with bolts 55 through the metal spacer block 53 placed. The descending position restricting plate 51 has an outer shape that is substantially the same as the top plate of the case 11.

  A circular through hole 57 having a diameter that is slightly larger than that of the enlarged diameter portion 31 b at the upper end of the support rod 31 is formed at the center of the lowered position restricting plate 51. The load disk 29 is a disk-shaped member having an outer diameter smaller than the horizontal dimension of the descending position restricting plate 51, and is supported from below by a rolling part 37 inserted through the through hole 57 of the restricting plate 51. ing. When an appropriate air pressure is supplied to the air chamber 17, the load disk 29 is lifted away from the upper surface of the lowering position restricting plate 51 by the piston 12 being lifted upward by the pressure.

-Configuration of rolling parts-
FIG. 5A is an external perspective view of the rolling component 37 according to the first embodiment as viewed from above. FIG. 5B is a longitudinal sectional view of the rolling component 37 taken along the line Vb-Vb in FIG. The rolling part 37 constitutes a rolling mechanism that rolls the piston 12 with the support rod 31 as a main body with respect to the load disk 29. As shown in FIGS. 5 (a) and 5 (b), the upper end of the support rod 31 is expanded. A rolling element 39 as a second mechanism member attached to the diameter portion 31b, a receiving seat 43 as a first mechanism member attached to the load disk 29, and the rolling element 39 and the receiving seat 43 are held. A rubber holder 45, an upper fixing member 59 that fixes the holder 45 to the load disk 29, and a lower fixing member 61 that fixes the holder 45 to the enlarged diameter portion 31b at the upper end of the support rod 31 are configured. ing.

  The rolling element 39 includes a disk-shaped base plate 40 having substantially the same outer diameter as the enlarged diameter portion 31 b at the upper end of the support rod 31, and a columnar block member 41 fixed to the upper center portion of the base plate 40. ing. The base plate 40 and the block member 41 are both steel members, and are connected and integrated with each other.

  The base plate 40 protrudes to the side of the holder 45, and the protruding portion forms an annular flange portion 40a as a fastening piece. That is, the rolling component 37 has a flange portion 40a projecting laterally at the lower end portion. The flange portion 40a is fastened with bolts 42 at a plurality of locations to the enlarged diameter portion 31b at the upper end of the support rod 31. This will be described in detail later. A cylindrical portion 40b having a screw hole 40c penetrating in the vertical direction is provided at the center portion of the base plate 40 so as to protrude downward. A female screw is cut on the inner peripheral surface of the screw hole 40c of the tubular portion 40b.

  The block member 41 is provided with a shaft portion 41a that is screwed into the cylindrical portion 40b of the base plate 40 so as to protrude downward. A male screw is cut on the outer peripheral surface of the shaft portion 41a. The block member 41 is screwed into the screw hole 40c by screwing the male screw of the shaft portion 41a with the female screw in the cylindrical portion 40b of the base plate 40, and the lower end surface of the block member 41 is the peripheral portion of the screw hole 40c of the base plate 40. It is attached to the plate 40 in a state of being in close contact with the plate. The block member 41 has a spherical surface (dome-shaped) gentle curved surface 41b that protrudes upward and protrudes upward. The curved surface 41b is subjected to a quenching process for increasing the surface hardness.

  The receiving seat 43 is a steel block formed in a cylindrical shape having the same diameter as the block member 41 of the rolling element 39, and is a flat driven surface 43a that freely receives the curved surface 41b of the rolling element 39. On the lower surface. The rolling surface 43a is subjected to a quenching process for increasing the surface hardness. A plurality of screw holes 43b that open to the upper surface are formed in the upper portion of the receiving seat 43 at intervals in the circumferential direction. A portion of the load disk 29 corresponding to each screw hole 43b of the receiving seat 43 is formed with a through hole 29a having a receiving surface 29d for receiving the head of the bolt 47 inside. Then, the receiving seat 43 is fastened to the lower surface of the load disk 29 by screwing bolts 47 passed through the through holes 29a from the upper side of the disk 29 into the corresponding screw holes 43b and bolts 47 at a plurality of locations. It is attached by being.

  The holding tool 45 is made of a rubber material with little outgas and suitable for use in a clean room, for example, a rubber material mainly composed of fluorine rubber or chloroprene rubber, and has a cylindrical shape into which the rolling element 39 and the receiving seat 43 are fitted. Is formed. That is, the holder 45 has the rolling element 39 and the receiving seat 43 in a state where the inner peripheral surface is in close contact with the outer peripheral surface of both the members 39, 43, and the entire side periphery of both the members 39, 43 Thus, the curved surface 41b of the rolling element 39 and the driven surface 43a of the receiving seat 43 are constrained in a state where they are in contact with each other in the vertical direction.

  The hardness of the holder 45 is set to, for example, about 60 degrees (hardness measured with a hardness meter in accordance with JISK 6253). Accordingly, the holder 45 allows the rolling operation of the rolling element 39 by elastic deformation. And this holder 45 has the annular flange pieces 45a and 45b extended in the whole circumferential direction of the said holder 45 as a protrusion piece protruded to the outer side in the both ends in an up-down direction, respectively.

  Each of the upper fixing member 59 and the lower fixing member 61 is a metal member having a hollow portion at the center and formed in an annular shape having an outer diameter substantially the same as that of the base plate 40 of the rolling element 39. The holding tool 45 is press-fitted into the portion, so that the holding tool 45 is attached to a portion between the upper and lower flange pieces 45a and 45b. That is, the upper fixing member 59 and the lower fixing member 61 are configured so that the flange pieces 45a on both the upper and lower sides of the holder 45 are in a state where the inner peripheral surfaces of these members 59 and 61 are in close contact with the outer peripheral surface of the holder 45. The part between 45b is surrounded. The inner diameters of the upper fixing member 59 and the lower fixing member 61 are smaller than the outer diameters of the flange pieces 45a and 45b of the holder 45, and after both the members 59 and 61 are once attached to the holder 45, Since the flange pieces 45a and 45b function as a retaining member, the flange pieces 45a and 45b do not come out of the holder 45.

  In the upper fixing member 59, a plurality of screw holes 59a opened on the upper surface and a plurality of through holes 59b penetrating in the vertical direction are alternately formed at intervals in the circumferential direction. A portion of the load disk 29 corresponding to each screw hole 59a of the upper fixing member 59 has a receiving surface (not shown) similar to the through hole 29a for fastening the receiving seat 43 therein. 2) is formed.

  The upper fixing member 59 is fastened to the lower surface of the load disk 29 by screwing bolts 63 that pass through the through holes 29b from the upper side of the disk 29 into the corresponding screw holes 59a, and bolts 63 at a plurality of locations. It is attached by doing. As a result, the upper fixing member 59 presses the upper flange piece 45a of the holding tool 45 against the lower surface of the load disk 29 over the entire circumference, and is sandwiched between the load disk 29 and fixed. .

  The lower fixing member 61 is formed with a plurality of through holes 61a penetrating in the vertical direction at intervals in the circumferential direction. These through holes 61a correspond to the through holes 59b of the upper fixing member 59 in the vertical direction. A through hole 40 d penetrating in the vertical direction is formed in a portion of the base plate 40 of the rolling element 39 corresponding to each through hole 61 a of the lower fixing member 61. Furthermore, a screw hole 31c (see FIGS. 3 and 4) penetrating in the vertical direction is formed in a portion corresponding to each screw hole 4d of the base plate 40 in the enlarged diameter portion 31b at the upper end of the support rod 31.

  Then, the lower fixing member 61 and the base plate 40 have bolts 65 passed through the through holes 40d and 61a of the lower fixing member 61 and the base plate 40 in the corresponding screw holes 31c. It is attached by screwing and fastening with bolts 65 at a plurality of locations. As a result, the lower fixing member 61 presses the lower flange piece 45b of the holding tool 45 against the upper surface of the base plate 40 on the piston 12 over the entire circumference, and fixes the flange 45b between the base plate 40 and the lower fixing member 61. It is like that. Each bolt 42 that fastens the lower fixing member 61 and the base plate 40 is a hexagon socket head cap screw.

  A through hole 29c for removing the bolt 42 is formed as a work hole in a portion of the load disk 29 corresponding to the upper side of each bolt 42 for fastening the flange portion 40a of the rolling part 37. Each of these through holes 29c has a diameter that is substantially the same as or slightly larger than the outer diameter of the head of the bolt 42 that fastens the flange portion 40a of the rolling part 37.

  Although not shown, the case 11 is provided with an air supply / exhaust passage to the air chamber 17. The supply / discharge passage is an air flow path that is connected to an air reservoir tank by an air pipe and supplies and discharges air between the reservoir tank and the air chamber. In the middle of the air pipe, an orifice for attenuating fluctuations in air pressure due to air flow resistance, a valve for discharging air from the air chamber 17 to the atmosphere, and the like are disposed.

-Operation of isolator-
In the isolator 2 configured as described above, when the vertical vibration is received from the floor surface, the piston main body 13, the piston well 23, the support rod 31 and the like are moved up and down integrally by the action of the air spring 18, thereby The displacement in the vertical direction between the floor and the floor is absorbed, and an excellent vibration isolation effect is obtained with respect to the vibration in the vertical direction. Further, when receiving vibration in the left-right direction from the floor surface, the entire piston 12, that is, the piston main body 13, the piston well 23, and the support rod 31 oscillate with respect to the case 11 by the bending action of the diaphragm 15. The support rod 31 rolls with respect to the load disk 29 on the rolling surface 43 a of the receiving seat 43 by the rolling operation of the rolling element 39, and a combination of the swing of the whole piston 12 and the swing of the support rod 31. Thus, the displacement in the horizontal direction between the mounted device and the floor surface is absorbed, and an excellent vibration isolation effect can be obtained even with respect to the vibration in the horizontal direction.

-Rolling part replacement work-
FIGS. 6A and 6B are process diagrams showing the replacement work of the rolling parts 37. In the above-described isolator 2, the behavior characteristics related to the rolling operation of the rolling element 39, that is, the work for changing the degree of ease of swinging of the support rod 31, is the mechanical characteristic of the holder 45. It only needs to be replaced with one having a different curvature (such as hardness) or curved surface of the rolling element 39.

  In the replacement work of the rolling part 37, first, as shown in FIG. 6A, an L-shaped hexagon wrench 201 is passed through a through hole 29c as a work hole formed in the load disk 29, and the hexagon The bolt 42 is loosened by rotating the wrench 201 in a predetermined direction after engaging the hexagonal hole in the head of the bolt 42 fastening the flange portion 40a of the rolling part 37. When such operations are repeated to loosen all the bolts 42 that fasten the flange portion 40a of the rolling part 37, the rolling part 37 and the load disk 29 together with the piston 29 as shown in FIG. Can be removed from.

  Next, all the bolts 47 that fasten the receiving seat 43 to the load disk 29 are loosened with the hexagon wrench 201, and the rolling parts 37 are removed from the load disk 29. Then, another rolling part 37 having different mechanical characteristics of the holding tool 45 and the curvature of the curved surface 41b of the rolling element 39 is connected to the flange part 40a of the part 37 with the enlarged diameter part 31b at the upper end of the support rod 31 with a bolt 42. Install by fastening. Thereafter, the load disk 29 is placed above the rolling part 37, and the load disk 29 is attached to the rolling part 37 by fastening to the receiving seat 43 with a bolt 47.

  If it does in the above, the rolling component 37 of the isolator 2 can be replaced easily.

-Behavior of air chamber when pressure drops-
In the isolator 2 described above, when the pressure of the air spring 18 decreases for some reason, the load disk 29 is placed on the lowering position restricting plate 51 and the lowering stops, while the piston 12 is provided with a dedicated stopper mechanism. Because it is not, it will be pulled downward by its own weight. At this time, in the isolator 2 of the present embodiment, the holding tool 45 that restrains the rolling element 39 and the receiving seat 43 is connected to the load disk 29 and the support rod 31 with the flange pieces 45a and 45b being the upper fixing member 59 and the lower fixing member 59. The load disk 29 and the support rod 31 are connected by the holding tool 45 so that the positional relationship between the load disk 29 and the support rod 31 in the vertical direction is maintained. Maintained by the tool 45, the curved surface 41b of the rolling element 39 and the rolled surface 43a of the receiving seat 43 in contact therewith are not separated. Thus, the horizontal displacement of the support position of the receiving seat 43 by the rolling element 39 and, consequently, the support position of the load disk 29 is prevented.

-Effect of Embodiment 1-
Therefore, according to the first embodiment, it is not necessary to provide the isolator 2 with a stopper mechanism for restricting the excessive lowering of the piston 12 when the air pressure of the air spring 18 is lowered. Since the displacement is prevented, the displacement of the load disk 29 in the horizontal direction due to this can be substantially eliminated with a simple structure.

<< Embodiment 2 of the Invention >>
The precision vibration isolation table A according to the second embodiment is different from the first embodiment in the rolling component 37 of the isolator 2 and the structure around it. In the present embodiment, only the configuration of the isolator 2 different from that of the first embodiment will be described, and the same components will be described in detail in the first embodiment based on FIGS. Is omitted.

-Configuration of load disk-
FIG. 7 is a view corresponding to FIG. 3 of the isolator 2 of the second embodiment. FIG. 10 is a top view of the isolator 2 according to the second embodiment. In the first embodiment, the isolator 2 including the lowering position restricting plate 51 is described below the load disk 29. However, the isolator 2 of the second embodiment does not include the lowering position restricting plate 51 as shown in FIG. The tightening ring 21 is also used as a means for receiving the load disk 29 that is lowered when the air pressure in the air chamber 17 is lowered and restricting further downward movement.

  The load disk 29 is spaced above the piston body 13. The outer shape of the load disk 29 is substantially the same rectangular shape as the top plate of the case 11. When an appropriate air pressure is supplied to the air chamber 17, the load disk 29 is lifted away from the upper surface of the tightening ring 21 by the piston 12 being lifted upward by the pressure.

  A circular recessed portion 36 that is recessed upward is formed in a portion of the lower surface of the load disk 29 corresponding to the enlarged diameter portion 31 b at the upper end of the support rod 31. The recessed portion 36 has an inner peripheral surface that surrounds the internal space of the recessed portion 36, and is formed in a stepped shape in which a portion on the open end side located below is enlarged in diameter. That is, of the recessed portion 36, the portion on the opening end side constitutes a large diameter portion 36a formed with a relatively large diameter, and the other portion includes a small diameter portion 36b formed with a relatively small diameter. It is composed. A rolling part 37 is fitted into the small diameter portion 36 b of the recessed portion 36 of the load disk 29.

-Configuration of rolling parts-
FIG. 8 is an exploded perspective view showing the configuration of the piston 12 used in the isolator 2 of the second embodiment and the attachment structure to the case 11. Fig.9 (a) is a perspective view of the rolling component 37 used for the isolator 2 of this Embodiment 2, and FIG.9 (b) is the rolling component 37 in the IXb-IXb line | wire of Fig.9 (a). It is a longitudinal cross-sectional view. As shown in FIGS. 9A and 9B, the rolling component 37 includes a rolling element 39 similar to that of the first embodiment having a spherical surface (dome-shaped) curved surface 41b projecting upward, and the rolling element 39. A receiving seat 43 similar to that of the first embodiment having a horizontal driven surface 43a that freely receives the curved surface 41b of the moving element 39 and the outer peripheral surfaces of the rolling element 39 and the receiving seat 43 are integrated with each other. It is composed of a molded rubber holder 45.

  As in the first embodiment, the rolling element 39 is attached to the enlarged diameter portion 31b at the upper end of the support rod 31 by fastening the flange portion 40a with bolts 42 at a plurality of locations. Similarly to the first embodiment, the receiving seat 43 is also attached to the lower surface of the load disk 29 by fastening with bolts 47 at a plurality of locations. Further, in the portion of the load disk 29 corresponding to the upper side of each bolt 42 that fastens the flange portion 40a of the rolling element 39, as shown in FIGS. 7 and 10, the above-described embodiment for removing the bolt 42 is provided. 1 is formed as a work hole.

  The holding tool 45 is provided on the upper surface of the base plate 40 of the rolling element 39 so as to cover the entire outer peripheral surface of the block member 41 of the rolling element 39 and the entire outer peripheral surface of the receiving seat 43 while leaving the upper end portion slightly. The outer peripheral surface of the block member 41 and the outer peripheral surface of the receiving seat 43 are vulcanized and bonded. Accordingly, the holder 45 is fixed to the rolling element 39 and the receiving seat 43, and the rolling element 39 and the receiving seat 43 are in contact with the curved surface 41b and the rolling surface 43a. It is restrained by.

  The holder 45 is formed of the same rubber material as that of the first embodiment, and the outer peripheral surface is brought into contact with the inner peripheral surface of the small diameter portion 36b of the recessed portion 36 of the load disk 29 so that the small diameter portion 36b It is fitted. As a result, horizontal vibration generated in the support rod 29 is effectively damped.

-Operation of isolator-
Even with the isolator 2 having the above-described configuration, an excellent vibration isolation effect can be obtained with respect to vertical vibrations and horizontal vibrations by performing the same operation as in the first embodiment. In the isolator 5, when the vibration in the horizontal direction is isolated, that is, when the displacement in the horizontal direction between the mounted device and the floor surface is absorbed, the holding tool is accompanied with the rolling operation of the rolling element 39. The stress generated in 45 acts as a damper that suppresses the swinging of the support rod 31, and a damping effect that attenuates the horizontal vibration generated in the support rod 31 and, in turn, the piston 12 is obtained.

-Rolling part replacement work-
FIGS. 11A and 11B are process diagrams showing the replacement work of the rolling part 37 of the second embodiment. In the isolator 2 described above, the operation of changing the behavioral characteristics related to the rolling operation of the rolling element 39 and the damping characteristics against the vibration in the horizontal direction to the characteristics required according to the application and installation location of the precision vibration isolation table A are as follows. The moving part 37 is simply replaced with one having a different mechanical characteristic (such as hardness) of the holder 45. The replacement work of the rolling component 37 is basically the same as the procedure described in the first embodiment.

  That is, in the replacement work of the rolling parts 37, first, as shown in FIG. 11A, an L-shaped hexagon wrench 201 is passed through a through hole 29c as a work hole formed in the load disk 29, The bolt 42 is loosened by rotating the hexagon wrench 201 in a predetermined direction after engaging the hexagon wrench 201 with the hexagon hole in the head of the bolt 42 fastening the flange portion 40a of the rolling part 37. When such operations are repeated to loosen all the bolts 42 that fasten the flange portion 40a of the rolling part 37, the rolling part 37 and the load disk 29 together with the piston 12 as shown in FIG. Can be removed from.

  Next, all the bolts 47 that fasten the receiving seat 43 to the load disk 29 are loosened with the hexagon wrench 201, and the rolling parts 37 are removed from the load disk 29. Then, another rolling part 37 having different mechanical characteristics of the holder 45 is attached by fastening the flange part 40a of the part 37 to the enlarged diameter part 31b at the upper end of the support rod 31 with the bolt 42. After that, the load disk 29 is disposed above the piston body 13 by inserting the rolling part 37 into the small diameter portion 36 b of the recessed portion 36. Then, the load disk 29 is attached to the rolling part 37 by fastening the receiving seat 43 of the rolling part 37 from the upper side of the load disk 29 to the bottom surface of the small diameter part 36 b of the recessed part 36 with a bolt 47.

  If it does in the above, the rolling component 37 of the isolator 2 can be replaced easily.

-Behavior of air chamber when pressure drops-
In the isolator 2 described above, when the pressure of the air spring 18 decreases for some reason, the load disk 29 is placed on the lowering position restricting plate 51 and the lowering stops, while the piston 12 is provided with a dedicated stopper mechanism. Because it is not, it will be pulled downward by its own weight. At this time, in the isolator 2 of the present embodiment, the holder 45 that restrains the rolling element 39 and the receiving seat 43 is fixed to the members 39 and 43 by vulcanization, that is, rolling. Since the moving element 39 and the receiving seat 43 are integrated by the holder 45, the curved surface 41b of the rolling element 39 and the rolled surface 43a of the receiving seat 43 that contacts the moving element 39 are not separated from each other. Thus, the horizontal displacement of the support position of the receiving seat 43 by the rolling element 39 and, consequently, the support position of the load disk 29 is prevented.

-Effect of Embodiment 2-
Therefore, also in the second embodiment, as in the first embodiment, the horizontal displacement of the load disk 29 can be substantially eliminated with a simple structure.

  Further, according to the second embodiment, the holder 45 of the rolling part 37 acts as a damper that suppresses the swinging of the support rod 31 with the rolling operation of the rolling element 39. In addition, since the rolling part 37 of the present embodiment is fitted into the recessed portion 36 of the load disk 29 and the outer peripheral surface is in contact with the inner peripheral surface of the recessed portion 36, the holder 45 exhibits a high damper effect. In addition, the horizontal vibration generated in the piston 12 can be effectively damped. Accordingly, even if the hollow portion 24 in the piston well 23 does not contain vibration-damping oil such as silicone oil, it is necessary for the vibration in the horizontal direction according to the installation location and application of the precision vibration isolation table A. The attenuation effect can be obtained.

  Further, according to the second embodiment, since the rolling part 37 is fitted into the recessed portion 36, an extra space is prevented from being generated between the piston body 13 and the load disk 29, and the isolator is correspondingly increased. The height of 2 can be lowered. Thereby, the isolator 2 can be made compact.

<< Other Embodiments >>
In the first and second embodiments, the steel ball 33 is accommodated in the lower end portion of the support rod 31, and the lower portion of the steel ball 33 is supported by the well slug 26 so as to be freely rollable. Instead, a projecting portion having a spherical (dome-shaped) curved surface projecting upward may be provided at the bottom of the piston well 23, and the projecting portion may be brought into contact with the horizontal lower end surface of the support rod 31.

  In the first embodiment, the holder 45 is fixed to the load disk 29 with the upper flange piece 45a sandwiched between the load disk 29 and the upper fixing member 59, and the lower flange piece 45b is supported to the support rod 31. A mode in which the upper end diameter-expanded portion 31 b and the lower fixing member 61 are sandwiched and fixed to the support rod 31 will be described. In the second embodiment, the holder 45 is attached to the rolling element 39 and the receiving seat 43. Although the form fixed by vulcanization adhesion was demonstrated, it is not restricted to this.

  For example, the holder 45 is fixed to the support rod 31 by sandwiching the flange piece 45 b provided at the lower end portion between the enlarged diameter portion 31 b at the upper end of the support rod 31 and the lower fixing member 61 and added to the receiving seat 43. It may be fixed by sulfur bonding. The holder 45 is fixed to the rolling disk 39 by vulcanization adhesion, and is fixed to the load disk 29 by sandwiching a flange piece 45a provided at the upper end portion between the load disk 29 and the upper fixing member 59. It doesn't matter. That is, the holder 45 may be fixed to at least one member of the load disk 29 and the receiving seat 43 and at least one member of the support rod 31 and the rolling element 39.

  In the first and second embodiments described above, the rolling element 39 is attached to the enlarged diameter portion 31b at the upper end of the support rod 31 and the receiving seat 43 is attached to the load disk 29 as an example. However, the rolling elements 39 and the receiving seats 43 may be provided upside down. That is, the receiving seat 43 may be attached to the enlarged diameter portion 31 b at the upper end of the support rod 31, and the rolling element 39 may be attached to the load disk 29.

  In Embodiments 1 and 2, in order to connect the steel ball 33 and the well slug 26 at the lower end of the support rod 31, the rubber holding member 35 is vulcanized and bonded to all of them. For example, a predetermined range between the lower end portion of the steel ball 33 and the well slug 26 may be in a non-bonded state. In this way, the rolling operation between the steel ball 33 and the well slug 26 becomes smoother, and the influence of the holding member 35 on the swinging operation of the piston body 13 can be minimized.

  Further, in the second embodiment, the rubber holder 45 is vulcanized and bonded over the entire outer peripheral surface of both the members 39 and 43 in order to connect the rolling element 39 and the receiving seat 43. The rubber material of the holder 45 is prevented from entering between the curved surface 41b of the rolling element 39 and the driven surface 43a of the receiving seat 43, and the curved surface 41b and the driven surface 43a are not bonded. It is also possible to do. In this way, the rolling operation of the rolling element 39 becomes smoother, and the influence of the holder 45 on the swinging operation of the support rod 31 can be minimized.

  In the second embodiment, the embodiment in which the rolling component 37 is inserted into the recessed portion 36 formed in the load disk 29 has been described as an example. However, the present invention is not limited thereto, and the recessed portion 36 is not formed. A configuration in which the rolling component 37 is attached to the flat lower surface of the load disk 29 may be employed. Even with such a configuration, the stress generated in the holder 45 due to the rolling operation of the rolling element 39 still acts as a damper that suppresses the swinging of the support rod 31, and the horizontal generated in the piston 12. The vibration of the direction can be attenuated.

  Further, the replacement work of the rolling component 37 in the first and second embodiments is not limited to that of the embodiment. For example, the rolling component 37 is loaded from the piston 12 together with the load disk 29, and the rolling component 37 is loaded from the load disk 29. After removing in order, and then attaching another rolling part 37 having a different mechanical characteristic of the holder 45 by inserting it into the recess 36 and fastening it to the load disk 29 with a bolt 47, the load disk 29 You may attach by fastening the flange part 40a of the rolling components 37 attached to to the enlarged diameter part 31b of the support rod 31 with the volt | bolt 42. As shown in FIG. Further, after the load disk 29 is removed from the rolling part 37, the rolling part 37 may be removed from the support rod 31 to replace the rolling part 37, or the rolling part 37 may be replaced with the load disk 29. I do not care.

  Further, the structure of the isolator 2 is not limited to that of the first and second embodiments, and for example, a horizontal air spring may be provided in addition to the vertical air spring 18. Further, instead of the air spring 18, for example, a gas spring filled with nitrogen gas or the like can be used.

  In the first and second embodiments, the vibration isolator A is configured by using the four isolators 2. However, the vibration isolator A is not limited to such an anti-vibration base A. Therefore, the mounting plate 3 designed exclusively can be supported by 3 to 4 isolators 2, or the movable floor embedded in the grating floor of the clean room can be similarly supported by the isolator.

  As mentioned above, although preferable embodiment of this invention was described, the technical scope of this invention is not limited to the range as described in each said embodiment. It is understood by those skilled in the art that the above-described embodiments are examples, and that various modifications can be made to combinations of the respective constituent elements and processing processes, and such modifications are also within the scope of the present invention. It is a place.

  As described above, the present invention is useful for a gas spring type vibration isolator using a piston incorporating a rolling mechanism, and in particular, a substantial displacement of a load receiving member in the horizontal direction is substantially reduced with a simple structure. It is suitable for a gas spring type vibration isolator that is desired to be eliminated.

2 Isolator (Gas spring type vibration isolator)
3 Mounting plate (supported body)
11 Case 11a Opening 12 Piston 15 Diaphragm (flexible member)
18 Air spring 29 Load disc (load receiving member)
29c Through-hole 36 Concave portion 39 Roller (second component)
40a Flange (fastening piece)
41b Curved surface 42 Bolt 43 Receiving seat (first component)
43a Rolling surface 45 Holder 45a Flange piece (protruding piece)
45b Flange piece (protruding piece)
59 Upper fixing member 61 Lower fixing member

Claims (6)

A load receiving member that receives the load of the supported body is disposed above a case having an opening on the upper surface, a piston that supports the load receiving member is inserted into the case from the opening, and the lower surface of the piston is A gas spring that elastically supports the load of the supported body is configured by facing the inside of the case and closing the outer periphery of the piston from the periphery of the opening of the case with an annular flexible member. A gas spring vibration isolator,
A rolling mechanism for rolling the piston relative to the load receiving member;
The rolling mechanism has a first mechanism member attached to the load receiving member, and a second mechanism member attached to the piston,
Of the first mechanism member and the second mechanism member, one mechanism member is a rolling element having a convexly protruding curved surface, and the other mechanism member rolls on the curved surface of the rolling element. It is a receiving seat having a driven surface that is freely received,
The rolling element and the receiving seat are formed by surrounding the side surfaces of the two members with rubber holders that allow the rolling operation of the rolling element by elastic deformation, thereby enclosing the curved surface and the driven body. Restrained with the moving surface in contact with the top and bottom,
The retainer is fixed to at least one member of the load receiving member and the first mechanism member and to at least one member of the piston and the second mechanism member. Type vibration isolator. In the gas spring type vibration isolator according to claim 1,
The holder is formed in a cylindrical shape into which the rolling element and the receiving seat are fitted, and has protruding pieces protruding outward at both ends in the vertical direction,
The load receiving member is attached with an upper fixing member that presses and fixes the upper protruding piece of the holder against the load receiving member side,
A gas spring type vibration damping device, wherein a lower fixing member is attached to the piston for pressing and fixing a lower protruding piece of the holding tool against the piston. In the gas spring vibration isolator according to claim 2,
The protruding piece is an annular flange piece extending in the entire circumferential direction of the holder,
The gas spring type vibration damping device, wherein the upper fixing member and the lower fixing member press the flange piece over the entire circumference. In the gas spring type vibration isolator according to claim 1,
The gas spring vibration isolator, wherein the holder is fixed by vulcanization and adhesion to the rolling element and a receiving seat. In the gas spring type vibration isolator according to any one of claims 1 to 4,
On the lower surface of the load receiving member, a recessed portion that is recessed upward is formed,
The concave portion has an inner peripheral surface surrounding the internal space of the concave portion,
The gas spring type vibration isolator, wherein the holder is fitted into the recessed portion with an outer peripheral surface in contact with an inner peripheral surface of the recessed portion. In the gas spring type vibration isolator according to any one of claims 1 to 5,
The rolling element has a fastening piece projecting outward at the lower end, and is attached to the piston by fastening the fastening piece with a bolt,
A gas spring type vibration damping device, wherein a through hole for removing the bolt is formed in a portion of the load receiving member corresponding to the upper side of the bolt.

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