Fluid spring

Abstract

A fluid spring (30) for damping comprises: a base (33) having an opening (32p); a diaphragm (34) that covers the opening (32p) of the base (33) and that is provided in a flat plate shape extending to the edge; a pressing part (31) that is connected to the diaphragm (34) on a side opposite to the opening (32p); a fluid chamber (32) defined by the base (33) and the diaphragm (34); and a valve (40) that is provided to the base (33) and that supplies and discharges a fluid to and from the fluid chamber (32). The fluid flows through the valve (40) into the fluid chamber (32), thereby causing the diaphragm (34) to expand and deform toward the pressing part (31) side, and moving the pressing part (31) in a direction away from the opening (32p).

Description

Fluid Spring

[0001] The present technology relates to a fluid spring used for vibration suppression in an anti-vibration device used in, for example, semiconductor manufacturing equipment.

[0002] In vibration isolation devices that use fluid springs, there is a demand for improved performance in quickly stopping the vibration of the base plate that accompanies the acceleration and deceleration of the movable stage. For example, if the moving speed of a movable member such as a movable stage is increased to improve work efficiency, the impact when it stops will be greater. To quickly stop the vibration caused by that impact, it is necessary to improve vibration control performance. When vibration control is performed using a fluid spring, it is necessary to increase the response speed of the fluid spring.

[0003] According to the configuration of the fluid spring described in JP 2014-177963 A (Patent Document 1), a diaphragm constituting the fluid spring is provided between a piston member and a frame body so as to form an air chamber. Furthermore, a folded portion is provided around the periphery of the diaphragm so as to allow the piston member to move in its axial direction.

[0004] Japanese Patent Application Laid-Open No. 2014-177963

[0005] One way to improve the responsiveness of a fluid spring is to shorten its operating time, which can be done by reducing the volume of the air chamber of the fluid spring so that the diaphragm operates with a smaller amount of air inflow.

[0006] In the structure using a diaphragm with a folded portion disclosed in Patent Document 1, if an attempt is made to reduce the amount of air filling the folded portion of the diaphragm by narrowing the gap between the frame and piston member that form the air chamber so that the volume of the fluid chamber of the fluid spring is kept to a predetermined small volume, the diaphragm will become caught between the frame and the piston member if the position of the piston member is misaligned, which makes it difficult to adjust the position of the piston and to reduce the size of the fluid chamber of the fluid spring.

[0007] The object of the present technology is to solve the above-mentioned problem, and to provide a fluid spring that does not cause jamming of the folded portion of the diaphragm.

[0008] [1] The fluid spring according to the present technology comprises a fluid chamber component having an opening, an elastic membrane portion covering the opening of the fluid chamber component and extending to the edge in a flat plate shape, a pressing portion connected to the elastic membrane portion on the side opposite the opening, a fluid chamber defined by the fluid chamber component and the elastic membrane portion, and a fluid supply / discharge portion provided in the fluid chamber component for supplying and discharging fluid to and from the fluid chamber, and when the fluid flows from the fluid supply / discharge portion into the fluid chamber, the elastic membrane portion expands and deforms toward the pressing portion, moving the pressing portion in a direction away from the opening.

[0009] [2] The fluid chamber component has a wall portion and a vertical wall portion arranged to surround the periphery of the wall portion, and the opening is defined in the area surrounded by the vertical wall portion on the opposite side of the wall portion, and the edge portion of the elastic membrane portion is fixed to the end of the vertical wall portion. A fluid spring as described in [1].

[0010] [3] The fluid spring according to [2], wherein the wall portion includes a spring communication passage for allowing the fluid to flow into the fluid chamber.

[0011] [4] A fluid spring described in any of [1] to [3], wherein the fluid chamber component further includes a spacer arranged in contact with the wall surface portion to reduce the volume of the fluid chamber, and the spacer has a communication hole for connecting the spring communication passage and the fluid chamber.

[0012] According to this technology, because the diaphragm does not have a folded portion, even if the pressing portion moves in a direction perpendicular to the pressing direction due to an external force from an object to be pressed, the diaphragm will not become jammed. Therefore, if the diaphragm becomes jammed, the fluid chamber-forming portion that forms the fluid chamber and the pressing portion will become fixed by the jamming. However, because there is no such fixed state, vibrations from the member that fixes the fluid spring will not be transmitted to the object to be pressed by the pressing portion via the fluid spring. Furthermore, because the diaphragm does not have a folded portion, the amount of fluid to be filled in the folded portion can be reduced, making the fluid spring usable in applications requiring improved responsiveness.

[0013] Fig. 1 is a longitudinal sectional view showing the configuration of a vibration isolation apparatus of embodiment 1. Fig. 2 is a partial perspective view of the vibration isolation apparatus of embodiment 1, seen from one valve side. Fig. 3 is a block diagram showing control of supply and exhaust of fluid to and from a fluid chamber of the vibration isolation apparatus of embodiment 1. Fig. 4 is a partial longitudinal sectional view showing the configuration of a vibration isolation apparatus of embodiment 2. Fig. 5 is a first schematic view showing variations in valve arrangement of another embodiment. Fig. 6 is a second schematic view showing variations in valve arrangement of another embodiment. Fig. 7 is a third schematic view showing variations in valve arrangement of another embodiment. Fig. 8 is a partial longitudinal sectional view explaining the configuration of a vibration isolation apparatus in which the capacity of a fluid chamber is changed, of another embodiment.

[0014] Hereinafter, embodiments of the present technology will be described. The same or corresponding parts will be denoted by the same reference characters, and description thereof will not be repeated in some cases.

[0015] In each embodiment described below, when referring to the number, amount, dimensions, etc., the scope of the present technology is not necessarily limited to the number, amount, dimensions, etc., unless otherwise specified. In the following embodiments, each component is not necessarily essential to the present technology, unless otherwise specified. The same reference numerals are used for the same or equivalent parts, and redundant descriptions may not be repeated. It is intended from the beginning that the configurations in the embodiments may be used in appropriate combination.

[0016] In this specification, the terms "comprise," "include," and "have" are open-ended. That is, when a certain configuration is included, other configurations may or may not be included. Furthermore, the present technology is not necessarily limited to those that achieve all of the effects mentioned in the present embodiment.

[0017] (Embodiment 1: Vibration isolation device 1) The configuration of a vibration isolation device 1 of this embodiment will be described with reference to Figures 1 and 2. Figure 1 is a vertical cross-sectional view showing the configuration of the vibration isolation device 1, and Figure 2 is a partial perspective view of the vibration isolation device 1 as seen from one valve side.

[0018] The vibration isolation device 1 has a bilaterally symmetrical configuration as shown in the drawing, with a boundary being an imaginary plane that includes the vertical line VL and is perpendicular to the directional axis of the pressing direction of the piston-shaped pressing portion 31. In the following explanation, a bilaterally symmetrical vibration isolation device 1 will be described, but it is not limited to a bilaterally symmetrical configuration, and a vibration isolation device having either one of the configurations may also be used.

[0019] The vibration isolation device 1 includes a flat vibration isolation table 10 on which an object to be isolated from vibration, such as a semiconductor manufacturing device, is mounted, a support section 20 provided vertically below the vibration isolation table 10, a vibration damping fluid spring 30 that presses the support section 20 horizontally, a valve 40, and a fixing section 50 that fixes the valve 40. The vibration damping fluid springs 30 are provided so as to be able to press against the support section 20 in a pair that are symmetrical with respect to an imaginary plane including a vertical line VL. One valve 40 is connected to one vibration damping fluid spring 30 so as to be able to supply fluid, but it is also possible to connect multiple valves to one vibration damping fluid spring 30.

[0020] The support section 20 includes a support plate 22 provided on the vibration isolation table 10, and a connecting section 21 extending downward from the support plate 22 and connected to the vibration damping fluid spring 30. The support section 20 supports the vibration isolation table 10 by at least providing horizontal support from the vibration damping fluid spring 30. The fixing section 50 includes a side wall section 51 that fixes the valve 40, and a mounting wall 52 that supports the side wall section 51.

[0021] As will be described later, the valve 40 functions as a valve for switching the fluid flow path to control the supply and / or discharge of fluid to the fluid chamber 32, and is a device controlled by the control unit 100. Air is used as the fluid, but the fluid is not limited to air. An inert gas such as nitrogen or a liquid can also be used. The valve 40 has a supply port that can supply the fluid to the fluid chamber 32. The valve 40 only needs to be able to supply the fluid to the fluid chamber 32. In this embodiment, the valve 40 has an intake port (not shown) that connects to a fluid supply source such as a compressor and an exhaust port (not shown) that connects to an exhaust path (not shown). The supply port of the valve 40 is connected to the fixed part fluid passage 51h.

[0022] The valve 40 may be fixed to the side wall portion 51 by fixing the valve 40 to the surface of the side wall portion 51, or by providing a bottomed hole in the thickness direction of the side wall portion 51 and embedding the valve 40 in this hole to fix the valve 40 to the side wall portion 51.

[0023] The above-described configurations of the vibration isolation table 10, the support portion 20, and the fixing portion 50 are merely examples, and the present invention is not limited to these configurations.

[0024] The vibration damping fluid spring 30 includes a base portion 33, a diaphragm 34, a pressing portion 31, a fluid chamber 32, and a spring communication passage 33h. The base portion 33 has an opening 33p, a concave inner wall, and an internal space. The base portion 33 functions as a fluid chamber component, and the opening 33p is defined by its inner wall. The diaphragm 34 is provided as an elastic membrane portion that covers the opening 33p of the base portion 33. By covering the opening 33p, it prevents fluid from leaking out of the opening 33p. The pressing portion 31 is provided on the opposite side of the diaphragm 34 from the opening 33p and is connected to the diaphragm 34. The fluid chamber 32 is defined by the base portion 33 and the diaphragm 34, and in this embodiment, it is composed of the inner wall and bottom of the base portion 33 and the inner surface of the diaphragm 34. The spring communication passage 33h is provided in the base portion 33 and supplies and / or discharges fluid into the fluid chamber 32. In addition, the connecting portion 21 of the support portion 20 is connected to the side of the pressing portion 31 opposite to the side connected to the diaphragm 34.

[0025] The base portion 33 includes a circular wall portion 33a and a cylindrical standing wall portion 33b surrounding the periphery of the wall portion 33a. A spring communication passage 33h is provided in the wall portion 33a. An opening 33p is defined in an enclosed end 33t of the standing wall portion 33b on the opposite side from the wall portion 33a. The edge of the diaphragm 34 is fixed to the end 33t of the standing wall portion 33b by, for example, an annular pressing member 33c. The pressing member 33c is screwed into the end 33t of the standing wall portion 33b using bolts or the like. The diaphragm 34 is fixed to the base portion 33 with a predetermined tension applied. The tension applied to the diaphragm 34 is sufficient as long as the diaphragm 34 is positioned at a predetermined position relative to the base portion 33 and can be expanded by the fluid filled in the fluid chamber 32, and is set appropriately depending on the material and film thickness of the diaphragm 34, which are set according to the degree to which the fluid chamber 32 will expand due to the expansion of the diaphragm 34. The diaphragm 34 is provided on the base portion 33 in a state in which tension is applied by the pressing member 33c, and therefore can be connected to the pressing portion 31 without providing a folded portion. The fluid chamber 32 is composed of the surface of the wall portion 33a facing the diaphragm 34, the inner circumferential surface of the upright wall portion 33b, and the inner surface of the diaphragm 34.

[0026] The diaphragm 34 expands when pressed by the fluid that has flowed into the fluid chamber 32, and transmits the pressure received from the fluid to the pressing portion 31, pressing and moving the pressing portion 31. Furthermore, as the amount of fluid that has flowed into the fluid chamber 32 decreases, the pressure on the diaphragm 34 by the fluid is released, and the diaphragm 34 returns to its initial position before expansion. The diaphragm 34 preferably has elasticity so that it can return to its initial position after such displacement, and the material and film thickness are appropriately selected depending on the usage conditions, such as the pressing force and durability to which the diaphragm 34 is subjected, and natural or synthetic rubber materials can be used.

[0027] In this embodiment, the fluid chamber 32 maintains a predetermined volume to ensure a predetermined responsiveness, and therefore, the base portion 33 preferably has strength sufficient to maintain the volume of the fluid chamber 32. The base portion 33 maintains the volume of the fluid chamber 32 according to the application. The wall portion 33a maintains the standing wall portion 33b and is connected to the side wall portion 51 to maintain the vibration damping fluid spring 30, so the thickness and material used are appropriately selected depending on the pressure applied to the fluid chamber 32, etc. The diameter of the spring communication passage 33h as a flow path is specified depending on the flow rate and flow velocity of the fluid passing through.

[0028] When the fluid flows from the spring communication passage 33h into the fluid chamber 32, the diaphragm 34 expands and deforms toward the pressing portion 31, moving the pressing portion 31 in a direction away from the wall surface portion 33a.

[0029] A fixed portion fluid passage 51h is provided in the side wall portion 51. One end of the fixed portion fluid passage 51h is directly connected to the spring communication passage 33h. A valve 40 is fixed to the surface of the side wall portion 51 opposite the base portion 33. The valve 40 has a valve fluid supply / discharge port 40h that supplies fluid to the vibration damping fluid spring 30. The other end of the fixed portion fluid passage 51h is directly connected to the valve fluid supply / discharge port 40h of the valve 40.

[0030] In the above description, "directly connected" means that no other connecting member is interposed. Note that the use of a leakage suppression member such as a sealant to prevent fluid from leaking to the outside is also included in the "directly connected" configuration. By connecting the vibration damping fluid spring 30 and the valve 40 to the side wall portion 51 without any intervening member such as a connecting member, the path length of the flow path can be shortened, and a path length that ensures sufficient responsiveness can be achieved.

[0031] In this embodiment, the material and thickness of the sidewall portion 51 are not limited as long as it can maintain the vibration damping fluid spring 30 and the valve 40 in the horizontal direction. The fixed portion fluid passage 51h is provided to communicate with the spring communication passage 33h, and the diameter of the passage is determined according to the flow rate and flow velocity of the fluid passing through. In this embodiment, the center lines CL of the through holes of the valve fluid supply / discharge port 40h, the fixed portion fluid passage 51h, and the spring communication passage 33h are arranged coaxially in the horizontal direction.

[0032] In this embodiment, a fluid spring using a diaphragm 34 as an elastic membrane portion can be used as a vibration-damping fluid spring in a vibration-damping device. This vibration-damping device can include a vibration-damping table on which an object to be vibration-damped is mounted, a support portion that vertically supports the vibration-damping table, a vibration-damping fluid spring that presses the support portion horizontally and has a spring communication passage that communicates with a fluid chamber provided therein, and a valve having a valve fluid supply / discharge port that supplies or discharges fluid to the vibration-damping fluid spring, and the vibration-damping fluid spring uses the diaphragm 34 as the elastic membrane portion. The valve can also be fixed to a fixed portion, and the fixed portion can be configured with a fixed portion fluid passage that has a spring communication passage connected to one side of the fixed portion and a valve fluid supply / discharge port connected to the other side. This fluid spring can be used as an actuator, but it can also be used for vibration damping or vibration-damping.

[0033] (Control System) A control system for introducing or discharging fluid into or from the fluid chamber 32 of the vibration isolation apparatus 1 having the above-described configuration will be described with reference to Fig. 3. Fig. 3 is a block diagram showing the control of introducing or discharging fluid into or from the fluid chamber 32 of the vibration isolation apparatus 1.

[0034] A control unit 100 on the main device side is connected to the valve 40 and controls the switching operation of the valve 40. An air supply system 200 is connected to the valve 40, and the introduction of fluid into the valve 40 is controlled by the control unit 100. An exhaust system 300 is connected to the valve 40, and the exhaust of fluid to the valve 40 is controlled by the control unit 100.

[0035] (Actions and Effects) As described above, according to the vibration isolation device 1 using the vibration damping fluid spring 30 in this embodiment, the diaphragm 34 is provided in a flat plate shape up to the edge and stretched with a predetermined tension, so that the opening 33p of the concave base portion 33 is blocked, and when fluid flows into the fluid chamber 32, the diaphragm 34 expands and presses the pressing portion 31, activating the pressing portion 31.

[0036] As a result, unlike conventional fluid springs, there is no folded portion provided around the periphery of the diaphragm, so the volume of the fluid chamber 32 is set to a predetermined volume, and the vibration damping fluid spring 30 operates with the pressing portion 31, making it possible to provide a small-volume vibration damping fluid spring 30 that is easy to attach to the fixed portion 50. Furthermore, it is also possible to suppress the transmission of vibrations in the direction of the opening 33p of the base portion 33.

[0037] Furthermore, since there is no folded portion provided at the peripheral edge of the diaphragm, there is no impediment to the vertical freedom of the pressing portion 31 due to the folded portion getting caught in the pressing portion 31. Furthermore, the work of attaching the vibration damping fluid spring 30 to the fixing portion 50 can be made easier.

[0038] By adopting this configuration, it is possible to obtain the sufficient response speed required for a vibration-damping fluid spring as a vibration-damping actuator. For example, the vibration-damping device 1 of this embodiment can be suitably used in a vibration-damping table of a semiconductor manufacturing device incorporating a high-speed stage.

[0039] Furthermore, the valve fluid supply and discharge port 40h of the valve 40 is directly connected to the side wall portion 51 of the fixed portion 50 that fixes the vibration damping fluid spring 30, and the supply paths for the fluid are limited to the fixed portion fluid passage 51h and the spring connecting passage 33h, with a minimal piping configuration that does not involve any other pipe lines, resulting in a structure that minimizes the volume of the passages and makes it possible to further improve the response speed.

[0040] It should be noted that the configuration is not limited to that shown in Figures 1 and 2, and the above configuration in which a diaphragm 34 that is flat up to the edge and stretched with a predetermined tension is used as the vibration damping fluid spring 30 may also be adopted in a configuration in which a separate pipeline is used to connect the vibration damping fluid spring 30 and the valve 40.

[0041] (Embodiment 2) Another embodiment of a vibration isolation device will be described with reference to Fig. 4. Fig. 4 is a partial vertical cross-sectional view showing the configuration of a vibration isolation device 1A of embodiment 2. The basic configuration is the same as that of the vibration isolation device 1 having the vibration damping fluid spring 30 in embodiment 1 described above, but the positions of the valve fluid supply and discharge port 40h, the fixed portion fluid passage 51h, and the through holes of the spring communication passage 33h are offset from the horizontal center line CL of the pressing portion 31.

[0042] The spring communication passage 33h is provided at a position shifted upward with respect to the center line CL, and the fixed portion fluid passage 51h is provided so as to incline upward as it moves away from the pressing portion 31.

[0043] For example, when the valve 40 is to be disposed at a position displaced from the horizontal center line CL due to design constraints, a configuration such as the vibration isolation device 1A of this embodiment is selected.

[0044] Even with this configuration, it is possible to directly connect the valve fluid supply and discharge port 40h of the valve 40 to the side wall portion 51 of the fixing portion 50 that fixes the vibration damping fluid spring 30, and the same effects as those of the above-mentioned embodiment 1 can be obtained.

[0045] Other Embodiments The configuration of a vibration isolation device according to still another embodiment will be described with reference to Fig. 5 to Fig. 8. Fig. 5 to Fig. 7 are first to third schematic diagrams showing variations in the arrangement of the valve 40, and Fig. 8 is a partial vertical cross-sectional view illustrating the configuration of a vibration isolation device in which the capacity of the fluid chamber 32 is changed.

[0046] Figure 5 is a schematic diagram viewed from the valve 40, showing a case in which one valve 40 is provided in the vibration isolation device 1 shown in embodiment 1, where the center lines CL of the valve fluid supply and discharge port 40h, the fixed part fluid passage 51h, and the through holes of the spring communication passage 33h are arranged coaxially in the horizontal direction.

[0047] The number of valves 40 is not limited to one, but may be two as shown in FIG. 6, or four as shown in FIG. 7, or five or more valves 40 may be provided.

[0048] 8, a spacer 80 may be disposed in contact with the wall surface portion 33a of the fluid chamber 32 of the base portion 33 in order to reduce the volume of the fluid chamber 32. The spacer 80 is provided with a communication hole 80h for communicating between the spring communication passage 33h and the fluid chamber 32. The communication hole 80h may be configured as a single passage like the spring communication passage 33h, or may branch into multiple holes toward the fluid chamber 32 as shown in FIG.

[0049] Although the embodiments of the present technology have been described above, the disclosed embodiments should be considered to be illustrative in all respects and not restrictive. The scope of the present technology is defined by the claims, and it is intended to include all modifications within the meaning and scope of the claims.

[0050] 1 Vibration isolation device, 1A Vibration isolation device, 10 Vibration isolation table, 20 Support portion, 21 Connection portion, 22 Support plate, 30 Vibration damping fluid spring, 31 Pressing portion, 32 Fluid chamber, 33 Base portion, 33a Wall portion, 33b Standing wall portion, 33c Pressing member, 33h Spring communication passage, 33p Opening, 33t End portion, 34 Diaphragm, 40 Valve, 40h Valve fluid supply and discharge port, 50 Fixed portion, 51 Side wall portion, 51h Fixed portion fluid passage, 52 Mounting wall, 80 Spacer, 80h Communication hole, 100 Control portion, 200 Air supply system, 300 Exhaust system.

Claims

1. A fluid spring comprising: a fluid chamber component having an opening; an elastic membrane portion covering the opening of the fluid chamber component and extending flat to the edge; a pressing portion connected to the elastic membrane portion on the side opposite the opening; a fluid chamber defined by the fluid chamber component and the elastic membrane portion; and a fluid supply and discharge portion provided on the fluid chamber component for supplying and discharging fluid to and from the fluid chamber; wherein when the fluid flows into the fluid chamber from the fluid supply and discharge portion, the elastic membrane portion expands and deforms towards the pressing portion, thereby moving the pressing portion in a direction away from the opening.

2. A fluid spring as described in claim 1, wherein the fluid chamber component has a wall portion and a vertical wall portion arranged to surround the periphery of the wall portion, the opening is defined in an area surrounded by the vertical wall portion on the opposite side to the wall portion, and the edge portion of the elastic membrane portion is fixed to an end portion of the vertical wall portion.

3. The fluid spring according to claim 2, wherein the wall portion includes a spring communication passage for allowing the fluid to flow into the fluid chamber.

4. A fluid spring as described in claim 3, wherein the fluid chamber component further includes a spacer arranged in contact with the wall portion to reduce the volume of the fluid chamber, and the spacer is provided with a communication hole for communicating between the spring communication passage and the fluid chamber.

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