Composite seal structure, seal structure, and sealing method by means of composite seal structure

Abstract

This composite seal structure 1 comprises an annular metal member (2) in which a recessed groove (2a) continuous with the entire circumference on the outer peripheral side or the inner peripheral side is formed, and an elastomer member (3) having a part to be stored (3a) fitted into the recessed groove (2a) of the metal member (2) and projecting parts (3b) which are continuous with the part to be stored (3a) and which a pair of flange parts (10) contact. The composite seal structure is sandwiched by the pair of flange parts (10). Only the projecting parts (3b) are brought into contact with the pair of flange parts (10) at the time of non-compression and the start of compression. The projecting parts and the deformed metal member 2 are brought into contact with the pair of flange parts (10) in a compressed state at a predetermined compression rate or higher, and the space between the pair of flange parts (10) is sealed.

Description

Composite seal structure, seal structure, and sealing method using composite seal structure

[0001] The present invention relates to a composite seal structure, a seal structure, and a sealing method using the composite seal structure.

[0002] Conventionally, rubber O-rings have been used in semiconductor manufacturing equipment or liquid crystal panel surface treatment equipment to create a near-vacuum environment. However, in radical gas environments or corrosive environments, rubber O-rings have poor corrosion and radical resistance, so it is known that a seal material having an elastic seal body and a corrosion-resistant ring made of fluororesin is used (for example, Patent Document 1).

[0003] However, like the rubber material, the resin material covering the rubber material also inevitably allows gas such as the atmosphere to permeate from the high-pressure side (atmospheric side) to the low-pressure side (negative pressure side).

[0004] Therefore, for example, a low-tightening-force composite metal seal is known, in which a rubber O-ring seal is integrated with the outer periphery of a metal seal shaped to be inserted into an O-ring seal groove, as disclosed in Patent Document 2. In this composite metal seal, the metal seal on the inner periphery prevents high-temperature corrosive gas from flowing into the rubber O-ring seal as much as possible.

[0005] Also known is a gasket having a metal layer or a plastic layer provided on the inner and / or outer peripheral surface of a ring-shaped rubber elastic body, as disclosed in Patent Document 3. In this gasket, the metal layer or the plastic layer is bonded to the ring-shaped rubber elastic body.

[0006] Japanese Patent No. 4625746 Japanese Patent Publication No. 2023-156213 Japanese Patent Publication No. 11-201288

[0007] In the composite metal seal, the elastic force of the composite metal seal is set to be approximately equal to that of a rubber O-ring seal, presumably so that the composite metal seal can replace a conventional rubber O-ring seal.

[0008] There is a need to improve the sealing performance even further compared to conventional composite seal structures while maintaining such a low fastening force.

[0009] In the case of Patent Document 3, the grooves in the metal or plastic layer are shallow, so the metal or plastic layer must be bonded to the ring-shaped elastic body, and the labor required for this bonding process can be a problem. On the other hand, if the metal or plastic layer is not bonded, it will be very likely to come off the ring-shaped elastic body, making handling difficult.

[0010] Similarly, in the device disclosed in Patent Document 2, the metal seal and the rubber O-ring seal are not bonded together, and the metal layer or plastic layer is easily separated from the ring-shaped elastic body, making handling difficult.

[0011] The present invention has been made in view of the above points, and an object of the present invention is to improve sealing performance by reducing gas permeation from an elastomer member while maintaining a low tightening force. Another object of the present invention is to improve sealing performance by reducing gas permeation from an elastomer member while maintaining a low tightening force, and to make the elastomer member less likely to come off and easier to handle.

[0012] In order to achieve the above object, in this invention, in a moderately compressed state, the elastomer member maintains sealing properties, while the metal member prevents corrosive gases or radical gases from flowing toward the elastomer member.

[0013] Specifically, the first invention comprises an annular metal member having a continuous groove formed around the entire circumference on either the outer or inner side, and an elastomer member having an accommodated portion that fits into the groove of the metal member and a protrusion portion that is continuous with the accommodated portion and against which a pair of flange portions abut, wherein when not compressed and when compression begins, only the protrusion portion abuts against the pair of flange portions, and when compressed at a predetermined compression rate or above, the protrusion portion and the deformed metal member come into contact to seal between the pair of flange portions, and the groove of the metal member has both ends approaching each other in a direction such that the minimum height dimension of both ends is smaller than the maximum height dimension of the accommodated portion.

[0014] With the above configuration, the elastomer member ensures sealing performance, while the metal member in compressed contact with the pair of flanges prevents corrosive gases or radical gases from flowing toward the elastomer member, reducing gas (such as the atmosphere) permeation from the elastomer member, improving sealing performance. Furthermore, because the elastomer member ensures sealing performance from the start of compression, the clamping force of the metal member can be reduced. Furthermore, because the metal member and the elastomer member are not easily disengaged, they will not slip out of place when sandwiched between the pair of flanges, ensuring appropriate sealing performance.

[0015] In a second aspect of the present invention, in the first aspect, the accommodated portion when uncompressed has a semicircular or semi-elliptical cross section, or has a groove with a V-shaped cross section.

[0016] According to the above-described configuration, the accommodated portion is appropriately accommodated in the recessed groove of the metal member so as not to come off when uncompressed or compressed.

[0017] In a third invention, in the first or second invention, the groove of the metal member has both ends approaching each other, thereby enveloping the entire circumference of the accommodated portion of the elastomer member, and the accommodated portion is accommodated within the groove so that it is difficult to come off when uncompressed or compressed.

[0018] According to the above-mentioned configuration, the metal member and the elastomer member are unlikely to come off, making transportation after assembly easy.

[0019] In a fourth sealing method, a composite seal structure including an annular metal member having a continuous groove formed around the entire circumference on either the outer or inner side, and an elastomer member having a accommodated portion that fits into the groove of the metal member and a protrusion portion that is continuous with the accommodated portion and against which a pair of flange portions abut is sandwiched between the pair of flange portions, and only the protrusion portion abuts against the pair of flange portions when the metal member is not compressed and when compression begins, and the protrusion portion and the deformed metal member are brought into contact with the pair of flange portions in a compressed state at a predetermined compression rate or above, thereby sealing between the pair of flange portions, and reducing gas permeation from the elastomer member while suppressing the flow of corrosive gas or radical gas by the metal member, and the groove of the metal member is pre-formed so that the accommodated portion is accommodated in the groove so that it is difficult to come out when the metal member is not compressed or compressed, by bringing both ends closer to each other.

[0020] With the above configuration, while the elastomer member ensures sealing performance, the metal member that is in contact with the pair of flanges in a compressed state can suppress the flow of corrosive gases or radical gases toward the elastomer member, thereby reducing gas permeation from the elastomer member, and since the elastomer member ensures sealing performance from the start of compression, the clamping force of the metal member can be reduced. Furthermore, since the metal member and the elastomer member are not easily detached, they do not shift relative to each other even when sandwiched between the pair of flanges, allowing for appropriate sealing performance and easy transportation after assembly.

[0021] A fifth aspect of the present invention is the fourth aspect of the present invention, wherein the metal member side is in a radical gas atmosphere.

[0022] According to the above configuration, in the compressed state, the metal member is in contact with the pair of flange portions, which prevents radical gas from flowing from the metal member into the elastomer member, thereby significantly improving the durability of the elastomer member.

[0023] In a sixth aspect of the present invention, in the fourth or fifth aspect, the elastomer member side is used in an atmosphere of -80°C or higher and 250°C or lower.

[0024] According to the above-mentioned configuration, it is possible to select a wide range of elastomer members from low temperature to high temperature.

[0025] In addition, a seventh invention comprises an annular metal member having continuous grooves formed around the entire circumference on either the outer or inner side, the open ends of the grooves being curved or bent so as to approach each other, and an annular elastomer member having a fitting portion that fits into the groove of the metal member and a protrusion portion that a pair of flange portions abut continuously against the fitting portion via a narrowed portion that is thinner than the fitting portion, wherein only the protrusion portion abuts against the pair of flange portions when not compressed and when compression begins, and wherein the protrusion portion and the deformed metal member come into contact when compressed at a predetermined compression rate or above, thereby sealing between the pair of flange portions, and the minimum distance between the opposing open ends of the metal member is smaller than the maximum height of the fitting portion, and the open ends of the metal member engage with the narrowed portions to prevent them from coming off.

[0026] With the above configuration, the elastomer member ensures sealing, and the metal member, which is in compressed contact with the pair of flange portions, prevents corrosive gases or radical gases from flowing toward the elastomer member, reducing the permeation of gases (such as the atmosphere) from the elastomer member, improving sealing performance. Furthermore, since the elastomer member ensures sealing from the start of compression, the clamping force of the metal member can be reduced. Furthermore, since the cross-sectional shape of the metal member is curved or bent so that the opening sides approach each other, and the opposing opening ends engage with the constricted portion of the elastomer member to prevent them from coming off, handling is extremely easy, such as when fitting the composite seal into the seal groove.

[0027] According to an eighth aspect of the present invention, in the seventh aspect, the curved arc-shaped cross-sectional portion of the metal member abuts against the pair of flange portions in the compressed state.

[0028] According to the above-mentioned configuration, the curved portion comes into contact with the flange portion, and therefore the inner surface of the seal groove is less likely to be damaged than when the end of the metal member has a sharp cross section.

[0029] In a ninth aspect, in the seventh aspect, the minimum distance between the opposing open ends is 70% to 99% of the maximum height of the fitting portion.

[0030] If the minimum distance between the opposing opening ends is less than 70% of the maximum height of the fitting portion, it becomes difficult to insert the fitting portion between the opening ends, and if it is greater than 99%, it becomes easy to pull out. However, with the above configuration, the fitting portion is easy to insert between the opening ends and is difficult to pull out once inserted, so the elastomer member does not come out of the metal member and is easy to handle.

[0031] The sealing structure of the tenth invention is a sealing structure that exhibits sealing performance when the composite sealing structure of any one of the seventh to ninth inventions is fitted into a groove in a first member and tightened by a second member, and the maximum height of the metal member is greater than the depth of the groove and less than the maximum height of the protrusion portion, and is greater than 100% and less than 130% of the depth of the groove.

[0032] According to the above-described configuration, the maximum height of the metal member is appropriately large relative to the depth of the recessed groove, so that the protrusions are compressed first and then compressed together with the metal member at an appropriate compression ratio.

[0033] In an eleventh aspect, in the tenth aspect, the maximum height of the protrusions is 105% or more and 145% or less of the depth of the recessed grooves.

[0034] If the maximum height of the protrusions is greater than 145% of the depth of the grooves, the compression rate of the protrusions will be too high, and if it is less than 105%, the metal member will be compressed without the protrusions being sufficiently compressed. However, with the above configuration, the depth of the grooves is set to an appropriate depth relative to the maximum height of the protrusions, so sealing performance is achieved when the elastomer member and metal member are compressed at an appropriate compression rate.

[0035] A twelfth sealing method of the present invention provides a composite seal structure comprising: an annular metal member having a continuous groove formed around the entire circumference on either the inner or outer periphery; an annular elastomer member having a fitting portion, a constricted portion, and a protrusion formed continuously therein, the constricted portion being fitted into the groove to prevent disengagement; the composite seal structure is sandwiched between a pair of flanges; when not compressed and at the start of compression, only the protrusions that are continuous with the fitting portion of the elastomer member via the constricted portion are brought into contact with the pair of flanges; when compressed at a predetermined compression rate or greater, the protrusions and the curved, arc-shaped cross-sectional portions of the deformed metal member are brought into contact with the pair of flanges, thereby sealing between the pair of flanges; and the metal member is configured to prevent corrosive gases or radical gases from flowing toward the elastomer member while reducing gas permeation from the elastomer member.

[0036] According to the above configuration, the constricted portion of the elastomer member is fitted into the recessed groove of the metal member to prevent it from coming off, making it easy to handle when clamping it between the pair of flanges. Furthermore, while the elastomer member ensures sealing, the metal member, which is in compressed contact with the pair of flanges, can reduce gas permeation from the elastomer member while preventing corrosive gases or radical gases from flowing toward the elastomer member, and the elastomer member ensures sealing from the start of compression, allowing the clamping force of the metal member to be reduced.

[0037] In a thirteenth aspect of the present invention, in the twelfth aspect, the metal member side is in a radical gas atmosphere.

[0038] According to the above configuration, in the compressed state, the metal member is in contact with the pair of flange portions, which prevents radical gas from flowing from the metal member into the elastomer member, thereby significantly improving the durability of the elastomer member.

[0039] As described above, according to the present invention, the elastomer member maintains sealing properties, and the metal member prevents corrosive gases or radical gases from flowing toward the elastomer member while reducing gas permeation from the elastomer member. Therefore, while maintaining a low tightening force, it is possible to improve sealing performance and make the product less likely to come loose and easier to handle.

[0040] 10B is an enlarged view of a portion I of FIG. 2B showing the composite seal structure according to embodiment 1 of the present invention. FIG. 10C is a plan view showing the composite seal structure. FIG. 10D is a cross-sectional view taken along line IIb-IIb of FIG. 2A. FIG. 10E is a cross-sectional view showing a state in which an elastomer member and a metal member are compressed and deformed by a pair of flange portions in a finite element method analysis. FIG. 10F is a graph showing the relationship between compression rate and tightening force. FIG. 10G is a cross-sectional view showing an example of the shape of a metal member. FIG. 10H is a cross-sectional view showing another example of the shape of a metal member. FIG. 10I ... elastomer member. FIG. 10I is a cross-sectional view showing another example of the shape of a elastomer member. FIG. 10I is a graph showing the results of a helium leak test. FIG. 10I is a graph showing the results of a radical resistance test. FIG. 10I is an enlarged cross-sectional view of portion IX of FIG. 10B showing the composite seal structure according to embodiment 2 of the present invention. FIG. 10I is a cross-sectional view taken along line XB-XB of FIG. 10A showing the composite seal structure. FIG. 10I is a perspective view showing the composite seal structure. FIG. 10I is an end view showing the seal structure before compression. Fig. 1 is a cross-sectional view showing a state in which an elastomer member and a metal member are in contact with a pair of flange portions, according to the analysis results of a finite element method analysis. Fig. 2 is a cross-sectional view showing a state in which an elastomer member and a metal member are compressed and deformed by a pair of flange portions, according to the analysis results of a finite element method analysis. Fig. 3 is a graph showing the relationship between compression rate and tightening force. Fig. 4 is a view corresponding to Fig. 9 showing a composite seal structure according to a first modified example. Fig. 5 is a view corresponding to Fig. 9 showing a composite seal structure according to a second modified example. Fig. 6 is a view corresponding to Fig. 9 showing a composite seal structure according to a third modified example.

[0041] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0042] 1 to 2B show a composite seal structure 1 according to a first embodiment of the present invention, which includes an annular metal member 2 having a continuous groove 2a formed around the entire circumference of its outer periphery.

[0043] In this embodiment, the cross section of the metal member 2 is generally semicircular and opens to the outer periphery. However, as shown in Figures 5A to 5D, it may have various shapes with recessed grooves 2a. The metal member 2 is made of stainless steel (SUS316L, SUS304, etc.), nickel alloys (C22, C276, 718, etc.), titanium, aluminum alloys, copper alloys, etc. The metal member 2 may be a molded product with a variable thickness, or a press-molded product with a constant thickness t. The thickness t is 0.15 to 0.60 mm, preferably 0.20 to 0.30 mm. The height H2 is 2 to 7 mm, preferably 2.8 to 3.8 mm.

[0044] 3, the composite seal structure 1 further includes an elastomer member 3 having an accommodated portion 3a that fits into the recessed groove 2a of the metal member 2 and a protruding portion 3b that is continuous with the accommodated portion 3a and against which a pair of flange portions 10, 10 abut. In the present embodiment 1, the accommodated portion 3a of the elastomer member 3 when not compressed has a semicircular shape.

[0045] In this embodiment 1, the accommodated portion 3a is formed around the entire circumference on the inner side, but when the metal member 2 is provided on the outer side, as in embodiment 2 described below, it is preferable that the accommodated portion 3a is provided on the outer side.

[0046] The elastomer member 3 is made of silicone rubber, fluororubber, ethylene-propylene rubber, nitrile rubber, butyl rubber, acrylic rubber, SBR, chloroprene rubber, TPE (thermoplastic elastomer), or the like.

[0047] The outer diameter OD of the elastomer member 3 is 20 to 1270 mm, preferably 300 to 700 mm, and the height H1 is 2.2 to 7.5 mm, preferably 3 to 4 mm. The radial width w0 of the protrusion 3b is, for example, 1.1 mm, but is not limited to this. The radial width W of the cross section of the composite seal structure 1 is 2 to 12 mm, preferably 2.5 to 4 mm.

[0048] As will be described in more detail later, the height H2 of the metal member 2 when uncompressed is set to be lower than the height H1 of the elastomer member 3 (H2

[0049] The minimum height H3 between the pair of end portions of the metal member 2 is preferably closer to each other. The minimum height H3 of the end portions is preferably smaller than the maximum height of the accommodated portion 3a. This feature is particularly evident when the metal member shown in Figures 5B to 5D is combined with the elastomer member 3 shown in Figures 6B to 6D.

[0050] As will be described in more detail later, when the compression ratio is equal to or greater than a predetermined value, the protrusion portion 3b and the deformed metal member 2 come into contact with each other, thereby sealing the space between the pair of flange portions 10, 10.

[0051] In this embodiment 1, the accommodated portion 3a when not compressed is semicircular, but as shown in Figures 6B to 6D, it may have a semi-elliptical cross section or a shape with a V-shaped groove in cross section.

[0052] - Finite Element Method Analysis - The relationship between the compression ratio and the tightening force of the composite seal structure 1 was analyzed using finite element method analysis software.

[0053] The units are mm for length, MPa for Young's modulus, and N for force. Based on the premise of static analysis and nonlinear structural analysis (contact, large deformation), the analysis was performed using a 1 / 2 axisymmetric model as shown in FIG. 3, taking advantage of the symmetry of the composite seal structure 1.

[0054] The pair of flanges 10, 10 were assumed to have sufficiently high rigidity relative to the composite seal structure 1, and were treated as rigid bodies. The large deformation effect was taken into account when performing the analysis based on the deformation amount and frictional contact. The compression ratio was calculated based on the height of the composite seal structure 1 when uncompressed, i.e., the height H1 of the elastomer member when uncompressed.

[0055] In this analysis, the elastomer member 3 used the physical property values ​​of silicone rubber with a hardness of 70, and the metal member 2 used the physical property values ​​of SUS316L.​

[0056] As described above, the height H2 of the metal member 2 when uncompressed is set lower than the height H1 of the elastomer member 3 (H2

[0057] In other words, initially only the upper and lower elastomer members 3 were in contact with the pair of flange portions 10, 10, but at around a compression rate of 5%, the metal member 2 also came into contact with the pair of flange portions 10, 10 with its outer periphery.

[0058] The clamping force then increases linearly when the compression ratio reaches approximately 7.5%. It can be seen that from 7.5% onwards, both the metal member 2 and the elastomer member 3 are in stable contact with the pair of flange portions 10, 10, demonstrating sealing performance.

[0059] When the target fastening force was reached, the compression rate was about 22% and the maximum fastening force was 7.1 N / mm.

[0060] Similar analyses were performed for the metal member 2 having each of the shapes shown in FIGS. 5A to 5D, and for the elastomer member 3 having the shape shown in FIG. 6A.

[0061] Table 1 shows the relationship between the thickness and height of each metal member and the clamping force when combined. Regardless of the shape, an appropriate clamping force was obtained, as shown in Table 1. The example shown in Figures 3 and 4 is the case of (Figure 5A-4) in Table 1. It was found that an appropriate clamping force can be obtained with an appropriate shape of the metal member 2 and an appropriate plate thickness t and height H2.

[0062]

[0063] ​- Sealing method using composite seal structure - The composite seal structure 1 described above is sandwiched between a pair of flanges 10, 10. There are no particular limitations on the equipment in which it can be used, but it can be used, for example, in a portion of a semiconductor manufacturing device or a surface treatment device for liquid crystal panels that connects gas or liquid flow paths and seals the inside and outside of the flow path at the pair of flanges 10, 10.

[0064] When not compressed, only the upper and lower protrusions 3b of the elastomer member 3 abut against the pair of flanges 10, 10, respectively. In the first embodiment, for example, the composite seal structure 1 is used such that the inner circumferential side (inside the flow passage) of the metal member 2 is in a radical gas atmosphere, and the outer circumferential side (outside the flow passage) of the elastomer member 3 is in an atmosphere of -80°C or higher and 250°C or lower. Since the protrusions 3b of the elastomer member 3 are in contact with the pair of flanges 10, 10 from the start of compression, sealing performance is reliably ensured.

[0065] Next, as the compression rate is gradually increased, for example, as described above, when the compression rate reaches around 5%, the metal member 2 also begins to abut against the pair of flange portions 10, 10, as shown in Figure 3, and when the compression rate is exceeded, the protrusion portion 3b and the deformed metal member 2 come into contact with the pair of flange portions 10, 10.

[0066] As a result, with an appropriate tightening force, the composite seal structure 1 seals between the pair of flange portions 10, 10, and the metal member 2 prevents radical gas from flowing toward the elastomer member 3, while reducing gas permeation from the elastomer member 3.

[0067] It is desirable that the maximum clamping force during compression be maintained at, for example, 3.9 N / mm or more and 25 N / mm or less. In other words, since the flexible elastomer member 3 ensures sealing performance, the maximum clamping force can be maintained at a lower value than with a single metal seal.

[0068] In this way, while the elastomer member 3 ensures sealing properties, the metal member 2, which is in compressed contact with the pair of flange portions 10, 10, can reduce the permeation of gas from the elastomer member 3 while suppressing the flow of radical gas toward the elastomer member 3, and since the elastomer member 3 ensures sealing properties, the tightening force of the metal member 2 can be reduced.

[0069] Furthermore, during compression, the metal member 2 is in contact with the pair of flange portions 10, 10 with an appropriate tightening force, so that the flow of radical gas into the elastomer member 3 is effectively suppressed, and the durability of the elastomer member 3 is significantly improved.

[0070] Furthermore, if the outer peripheral side of the elastomer member 3 is in an atmosphere of -80°C or higher and 250°C or lower, a wide range of elastomer members 3 can be selected as described above depending on the application.

[0071] Furthermore, as both ends of the groove 2a of the metal member 2 approach each other, the groove 2a encloses the entire circumference of the accommodated portion 3a of the elastomer member 3, so that the accommodated portion 3a is properly accommodated in the groove 2a of the metal member 2 so as not to come off when uncompressed or compressed. Therefore, since the metal member and the elastomer member are difficult to come off, they do not shift relative to each other even when sandwiched between a pair of flanges, and sealing performance can be properly demonstrated. In addition, the assembly is easy to transport after assembly.

[0072] Therefore, according to the composite seal structure 1 of this embodiment 1, the elastomer member 3 maintains sealing properties, and the metal member 2 reduces gas permeation from the elastomer member 3 while suppressing the flow of corrosive gases or radical gases toward the elastomer member 3, thereby improving sealing performance while maintaining a low tightening force.

[0073] - Confirmation of Effects by Helium Leak Test - FIG. 7 is a graph showing the results of a helium leak test using the composite seal structure 1 of the first embodiment of the present invention.

[0074] The test temperature was 22° C., the flow rate of helium was 50 mL / min (hood method), and the compression ratio was based on the initial height H1 of the seal = 3.60 mm.

[0075] Although details are not shown, the composite seal structure 1 was placed between a pair of flanges 10, 10 of a press machine and compressed. The amount of leakage was monitored using a helium leak detector, and a stable state was used as the background. Tape was wrapped around the outer periphery of the pair of flanges 10, 10 to form a hood (leaving a helium inlet). The amount of leakage was monitored for 10 minutes after helium began to be blown into the inlet. The amount of leakage when the amount of leakage stabilized was recorded as the saturated amount of leakage.

[0076] As a comparative example, a seal equivalent to that of the elastomer member 3 alone without the metal member 2 was also recorded in the same manner.

[0077] As can be seen from FIG. 7, it was found that the amount of leakage from the composite seal structure 1 was smaller than that in the case of using only the elastomer member 3, regardless of whether the compression ratio was 10%, 20%, or 22%.

[0078] - Confirmation of effect by radical resistance test - Although not shown in the figure, a radical exposure tester was used. The gas conditions were O ２ +CF ４ The pressure inside the processing chamber was set to 100 Pa with a ratio of 2:1, and the microwave output was set to 2500 W. The compression ratio was based on the initial height H1 of the composite seal structure 1, which was 3.60 mm.

[0079] The radical resistance effect was confirmed only for the composite seal structure 1 and the elastomer member 3 as a comparative example.

[0080] As shown in Figure 8, there was no weight loss (wear and tear of the elastomer member 3) in the composite seal structure 1, which confirmed that combining it with the metal member 2 is effective in improving radical resistance. On the other hand, when only the elastomer member 3 was used, it was found that significant wear and tear of the elastomer material occurred.

[0081] 9 and 10 show a composite seal structure 1' according to a second embodiment of the present invention. In the first embodiment, the metal member 2 is provided on the inner circumferential side, but in the second embodiment, the metal member 2' is provided on the outer circumferential side, since the outer circumferential side is in an environment of radical gas or the like. In this case, an elastomer member 3' is fitted into the inner circumferential groove 2a' from the inner circumferential side.

[0082] The composite seal structure 1' includes an annular metal member 2' having a continuous groove 2a' formed around the entire periphery of the outer periphery, and open ends 2b' of the groove 2a' that are curved so as to approach each other. A distance h4 between the pair of open ends 2b' is smaller than a maximum height h5 of the inner periphery of the groove 2a' (h4<h5).

[0083] In this second embodiment, the cross section of the metal member 2' is generally semicircular and opens to the outer periphery. However, as in the modified example described below, various shapes having a recessed groove 2a' may be used. The metal member 2' is made of stainless steel (e.g., SUS316L, SUS304), nickel alloy (e.g., C22, C276, 718), titanium, aluminum alloy, copper alloy, etc. It may be a molded product with a variable thickness, or a press-molded product with a constant thickness t. The thickness t is 0.15 mm to 0.60 mm, preferably 0.20 mm to 0.30 mm. The height h6 of the metal member 2' is 1.2 mm to 7 mm, preferably 1.8 mm to 3.8 mm. The maximum height h5 of the inner periphery of the recessed groove 2a' is h6 = h6 - 2 × t (h4 < h5 < h6).

[0084] The composite seal structure 1' further includes a fitting portion 3a' that fits into the recessed groove 2a' of the metal member 2', and an elastomer member 3' that is continuous with the fitting portion 3a' via a constricted portion 3c' that is thinner than the fitting portion 3a' and has a protrusion 3b' that abuts against a pair of flanges 10', 11' (shown only in FIG. 10D ) serving as a first member and a second member. In the second embodiment, the fitting portion 3a' of the elastomer member 3' when not compressed is semicircular.

[0085] In this embodiment 2, the fitting portion 3a' is formed around the entire outer periphery, but when the metal member 2' is provided on the inner periphery as in the first embodiment, it is preferable that the fitting portion 3a' is provided on the inner periphery.

[0086] The elastomer member 3' is made of silicone rubber, fluororubber, ethylene-propylene rubber, nitrile rubber, butyl rubber, acrylic rubber, SBR, chloroprene rubber, TPE (thermoplastic elastomer), or the like.

[0087] The inner diameter ID of the elastomer member 3' is 20 to 1270 mm, preferably 300 to 700 mm, and the maximum height h1 is 1.5 to 7.5 mm, preferably 2.5 to 4 mm. The compression ratio Δh1 of the elastomer member 3' is basically 5% to 30% of h1. As shown in FIG. 10D, the groove depth D is 70% to 95% of the maximum height h1 of the elastomer member (0.70h1≦D≦0.95h1), preferably 75% to 85% (0.75h1≦D≦0.85h1). The radial width W of the cross section of the composite seal structure 1' is 2 to 12 mm, preferably 2.5 to 6 mm. If the depth of the seal groove 12' formed in the first flange portion 10 is D, the height h6 of the metal member 2' is equal to or greater than the depth D of the seal groove 12' and smaller than the maximum height h1 of the elastomer member 3' (D≦h6

[0088] The height h2 of the constricted portion 3c' of the elastomeric member 3' is smaller than the maximum height h3 of the fitting portion 3a' and also smaller than the distance h4 between the open ends 2b' of the metal member 2' (h2<h4<h3). It is desirable to leave a suitable gap between the open ends 2b' and the constricted portion 3c' so that excessive force is not applied to the elastomeric member 3' from the metal member 2' during compression (0.75h4≦h2≦0.9h4). The distance h4 between the open ends 2b' is desirably 90% to 99% of the maximum height h1 of the elastomeric member 3' (0.9h3≦h4≦0.99h3).

[0089] ​As will be described in detail later, the height h6 of the metal member 2' when uncompressed is set to be lower than the height h1 of the elastomeric member 3' (h6

[0090] As will be described in detail later, when the compression ratio is equal to or greater than a predetermined value, the protrusion portion 3b' and the deformed metal member 2' come into contact with each other, thereby sealing the space between the pair of flange portions 10', 11'.

[0091] In the second embodiment, the fitting portion 3a' when not compressed has a semicircular cross section, but may have a different cross section as in the modified example described later.

[0092] - Finite Element Method Analysis - Using commercially available finite element method analysis software, an analysis was carried out on the relationship between the compression ratio and the tightening force of the composite seal structure 1'.

[0093] Based on the premise of static analysis and nonlinear structural analysis (contact, large deformation), the analysis was performed using the symmetry of the composite seal structure 1' as a 1 / 2 axisymmetric model as shown in Figs. 11A and 11B.

[0094] The amount of deformation of the pair of flanges 10', 11' was assumed to be sufficiently small relative to the amount of deformation of the composite seal structure 1', and the rigidity of the flanges 10', 11' was assumed to be sufficiently high, so the pair of flanges 10', 11' were treated as rigid bodies. The large deformation effect was taken into account when performing the analysis based on the amount of deformation and frictional contact. The compression ratio was calculated based on the height of the composite seal structure 1' when uncompressed, i.e., the height h1 of the elastomer member 3' when uncompressed.

[0095] In this analysis, the physical property values ​​of silicone rubber with a hardness of 70 were used for the elastomer member 3', and the physical property values ​​of SUS316L were used for the metal member 2'.

[0096] ​As described above, the height h2 of the metal member 2' when uncompressed is set lower than the height h1 of the elastomer member 3' (h2

[0097] In other words, initially only the upper and lower elastomer members 3' were in contact with the pair of flange portions 10', 11', but at around a compression rate of 13%, the outer periphery of the metal member 2' also came into contact with the pair of flange portions 10', 11'.

[0098] The clamping force increases linearly when the compression ratio reaches about 14%. It can be seen that from 14% onwards, both the metal member 2' and the elastomer member 3' are in stable contact with the pair of flange portions 10', 11', demonstrating sealing performance.

[0099] When the target fastening force was reached, the compression rate was about 22% and the maximum fastening force was 9.3 N / mm.

[0100] 10D , the composite seal structure 1′ described above is placed in the seal groove 12′ of the first flange portion 10 and sandwiched between the pair of flange portions 10′, 11′. There are no particular limitations on the equipment in which it can be used, but it can be used, for example, in a portion of a semiconductor manufacturing device or a surface treatment device for liquid crystal panels that connects gas or liquid flow paths and seals the inside and outside of the flow path between the pair of flange portions 10′, 11′.

[0101] ​When not compressed, only the upper and lower protrusions 3b' of the elastomer member 3' abut against the pair of flanges 10', 11', respectively. In the second embodiment, for example, the composite seal structure 1' is used such that the outer circumferential side (inside the flow passage) of the metal member 2' is in a radical gas atmosphere, and the inner circumferential side (outside the flow passage) of the elastomer member 3' is in an atmosphere of -80°C or higher and 250°C or lower. Since the protrusions 3b' of the elastomer member 3' are in contact with the pair of flanges 10', 11' from the start of compression, sealing performance is reliably ensured.

[0102] Next, as the compression ratio is gradually increased, for example, as described above, at a compression ratio of around 13%, the metal member 2' also begins to abut against the pair of flange portions 10', 11', and when compressed at or above that compression ratio, the protrusion portion 3b' and the deformed metal member 2' come into contact with the pair of flange portions 10', 11'.

[0103] As a result, with an appropriate tightening force, the composite seal structure 1' seals between the pair of flange portions 10', 11', and the metal member 2' suppresses the flow of radical gas toward the elastomer member 3' while reducing gas permeation from the elastomer member 3'.

[0104] It is desirable that the maximum clamping force during compression be maintained at, for example, 3.44 N / mm or more and 20.0 N / mm or less. In other words, since the flexible elastomer member 3' ensures sealing performance, the maximum clamping force can be maintained at a lower value than with a single metal seal.

[0105] In this way, while the elastomer member 3' ensures sealing properties, the metal member 2', which is in compressed contact with the pair of flange portions 10', 11', prevents radical gas from flowing toward the elastomer member 3', thereby reducing gas permeation from the elastomer member 3'.In addition, since the elastomer member 3' ensures sealing properties, the tightening force of the metal member 2' can be reduced.

[0106] Furthermore, during compression, the metal member 2' is in contact with the pair of flange portions 10', 11' with an appropriate tightening force, which effectively prevents radical gas from flowing into the elastomer member 3', thereby significantly improving the durability of the elastomer member 3'.

[0107] In addition, in this embodiment 2, the outer peripheral side of the elastomer member 3' is in an atmosphere of -80°C or higher and 250°C or lower, but by appropriately changing the material of the elastomer member 3', seals with various physical properties (temperature range, sealing performance, etc.) can be achieved.

[0108] Furthermore, since the groove 2a' of the metal member 2' encloses the fitting portion 3a' of the elastomer member 3' all around, the fitting portion 3a' is properly accommodated in the groove 2a' of the metal member 2' so as not to come off when uncompressed or compressed.

[0109] Furthermore, the cross-sectional shape of the metal member 2' is curved so that the opening ends 2b' approach each other, and the opposing opening ends 2b' engage with the constricted portion 3c' of the elastomer member 3' to prevent them from coming off, making handling extremely easy, for example, when fitting the composite seal structure 1 into the seal groove 12'.

[0110] Therefore, in the composite seal structure 1' of this embodiment 2, the elastomer member 3' maintains sealing properties, and the metal member 2' reduces gas permeation from the elastomer member 3' while suppressing the flow of corrosive gases or radical gases toward the elastomer member 3'. Therefore, while maintaining a low tightening force, the sealing performance is improved and the structure is difficult to come loose and easy to handle.

[0111] 13 shows a composite seal structure 101 according to a first modification of the second embodiment of the present invention, which differs from the second embodiment in particular in the shape of the metal member 102. In the following modifications, the same parts as those in FIGS. 9 to 11B are designated by the same reference numerals, and detailed description thereof will be omitted.

[0112] The metal member 102 of this modified example does not have an arc-shaped cross section, but rather has a tapered opening resembling the cross section of a teapot, formed by pressing a metal plate. In this modified example, the pair of opening ends 2b' approach each other, and the distance h4 between them is smaller than the maximum height h5 of the inner periphery of the groove 2a' (h4 < h5). The inner diameter of the opening end 102b of the metal member 102 is a uniform, flat shape, and the constricted portion 103c may also have a flat portion. The protrusion 103b has a shape similar to that of the second embodiment. The distance h4 between the opening ends 102b is narrower than the height h3 of the fitting portion 103a of the elastomeric member 103 and slightly larger than the height h2 of the constricted portion 103c (h2 < h4 < h3 < h5). This configuration achieves the same effects as the second embodiment.

[0113] --Modification 2-- FIG. 14 shows a composite seal structure 201 according to Modification 2 of the second embodiment of the present invention, which differs from the second embodiment in particular in that the shape of the metal member 202 is different.

[0114] The metal member 202 of this modification has a generally arc-shaped cross section, but the open ends 202b are bent so that they approach each other in the vertical direction. The distance h4 between the open ends 202b is narrower than the height h3 of the fitting portion 203a and slightly greater than the height h2 of the constricted portion 203c (h2<h4<h3<h5). This configuration achieves the same effects as the second embodiment.

[0115] The radially inner peripheral surface of the protrusion 203b of the elastomer member 203 is rounded. The neck portion 203c of the elastomer member 203 is narrow and has no flat surfaces above or below, matching the shape of the opening end 202b. However, the operational effects are the same as those of the second embodiment.

[0116] --Modification 3-- FIG. 15 shows a composite seal structure 301 according to Modification 3 of the second embodiment of the present invention, which differs from the second embodiment in particular in that the shape of the elastomer member 303 is different.

[0117] The metal member 302 of this modification has an arc-shaped cross section, as in the second embodiment, but the elastomer member 303 has a dogleg-shaped cross section with a recess on the radially outer side. In this case, there is a relatively large gap between the inner surface of the metal member 302. The distance h4 between the open ends 302b is narrower than the height h3 of the fitting portion 303a and slightly larger than the height h2 of the constricted portion 303c (h2<h4<h3<h5). This configuration achieves the same effects as the second embodiment.

[0118] That is, in the second embodiment, the metal member 2' is provided on the outer periphery side, but when the inner periphery side is in an environment of radical gas, etc., it is provided on the inner periphery side. In this case, the elastomer member is fitted into the groove on the outer periphery side from the outer periphery side.

[0119] In addition, in the second embodiment, the first member and the second member are a pair of flange portions 10', 11', but are not limited to a flange shape and may be configured as a pair of members with a seal groove formed in one of them.

[0120] It should be noted that the above-described embodiments are essentially preferred examples and are not intended to limit the scope of the present invention, its applications, or uses.

[0121] DESCRIPTION OF SYMBOLS 1 Composite seal structure 2 Metal member 2a Groove 3 Elastomer member 3a Receiving portion 3b Protrusion portion 10 Flange portion 1' Composite seal structure 2' Metal member 2a' Groove 2b' Opening end 3 Elastomer member 3a' Fitting portion 3b' Protrusion portion 3c' Narrowed portion 10', 11' Pair of flange portions (first member and second member) 12' Seal groove 101 Composite seal structure 102 Metal member 102b Opening end 103a Fitting portion 103c Narrowed portion 201 Composite seal structure 202 Metal member 202b Opening end 203 Elastomer member 203a Fitting portion 203b Protrusion portion 203c Narrowed portion 301 Composite seal structure 302 Metal member 302b Open end 303 Elastomer member 303a Fitting portion 303c Neck portion

Claims

1. An annular metal member having a concave groove formed continuously around the entire outer circumference or inner circumference, and an elastomeric member having a received portion that fits into the concave groove of the metal member and a ridge portion where a pair of flange portions abut continuously to the received portion, wherein only the ridge portion abuts against the pair of flange portions when not compressed and at the start of compression, and the ridge portion and the deformed metal member are in contact with each other in a compressed state with a predetermined compression ratio or more so that the space between the pair of flange portions is sealed, and the concave groove of the metal member has both ends approaching each other, and the minimum height dimension of the both ends is smaller than the maximum height dimension of the received portion. A composite seal structure characterized by this.

2. The composite seal structure according to claim 1, wherein the received portion when not compressed has a semi-circular or semi-elliptical cross-section, or has a groove with a V-shaped cross-section.

3. The concave groove of the metal member wraps around the received portion of the elastomeric member over the entire circumference by having both ends approach each other, and the received portion is housed so as not to easily come off during non-compression and compression within the concave groove. The composite seal structure according to claim 1 or 2, characterized by this.

4. A composite seal structure including an annular metal member having a concave groove formed continuously around the entire outer circumference or inner circumference, and an elastomeric member having a received portion that fits into the concave groove of the metal member and a ridge portion where a pair of flange portions abut continuously to the received portion, is sandwiched between the pair of flange portions in a state where the concave groove of the metal member wraps around the received portion of the elastomeric member over the entire circumference and the received portion is housed so as not to easily come off during non-compression and compression within the concave groove. Only the ridge portion is brought into contact with the pair of flange portions when not compressed and at the start of compression, and the ridge portion and the deformed metal member are brought into contact with the pair of flange portions in a compressed state with a predetermined compression ratio or more to seal the space between the pair of flange portions, and while suppressing the flow of corrosive gas or radical gas from the metal member to the elastomeric member side, it is configured to reduce the gas permeation from the elastomeric member. By making the concave groove of the metal member approach in a direction where both ends approach each other, the received portion is preformed so as to be housed so as not to easily come off during non-compression and compression within the concave groove. A sealing method using a composite seal structure, characterized by this.

5. A sealing method using the composite seal structure according to claim 4, characterized in that the side of the metal member is in an atmosphere of radical gas.

6. A sealing method using the composite seal structure according to claim 4 or 5, characterized in that the side of the elastomer member is used in an atmosphere of -80°C or higher and 250°C or lower.

7. An annular metal member having a concave groove continuously formed on the entire circumference of the outer peripheral side or the inner peripheral side, and the opening end of the concave groove being curved or bent so as to approach each other; and an annular elastomer member having a fitting portion fitted into the concave groove of the metal member and a ridge portion having a pair of flange portions continuously contacting each other through a constricted portion having a thickness smaller than that of the fitting portion. When not compressed and at the start of compression, only the ridge portion contacts the pair of flange portions, and in a compressed state with a predetermined compression rate or more, the ridge portion and the deformed metal member contact each other so that the space between the pair of flange portions is sealed. The minimum distance between the opposing portions of the opening ends of the metal member is smaller than the maximum height of the fitting portion, and the opening end of the metal member is engaged with the constricted portion to prevent detachment. A composite seal structure characterized by this.

8. The composite seal structure according to claim 7, characterized in that in the compressed state, the curved portion on the opening end side of the metal member is configured to contact the pair of flange portions.

9. The composite seal structure according to claim 7, characterized in that the minimum distance between the opposing portions of the opening ends is 70% or more and 99% or less of the maximum height of the fitting portion.

10. A seal structure in which the composite seal structure according to any one of claims 7 to 9 is fitted into the concave groove of the first member and tightened by the second member to exhibit seal performance. The maximum height of the metal member is larger than the depth of the concave groove, smaller than the maximum height of the ridge portion, and larger than 100% and 130% or less of the depth of the concave groove. A seal structure characterized by this.

11. The seal structure according to claim 10, characterized in that the maximum height of the ridge portion is 105% or more and 145% or less of the depth of the concave groove.

12. Prepare a composite seal structure in which the constricted portion of an annular elastomeric member, in which a fitting portion, a constricted portion, and a rib portion are continuously formed, is fitted into and retained in the concave groove of an annular metal member in which a concave groove continuous over the entire outer circumference or inner circumference is formed. Sandwich the composite seal structure between a pair of flange portions. At the time of non-compression and at the start of compression, bring only the rib portion continuous through the constricted portion into contact with the fitting portion of the elastomeric member against the pair of flange portions. In a compressed state with a predetermined compression ratio or more, bring the rib portion and the curved arc-shaped cross-sectional portion of the deformed metal member into contact with the pair of flange portions to seal between the pair of flange portions, and reduce gas permeation from the elastomeric member while suppressing the flow of corrosive gas or radical gas to the elastomeric member side by the metal member. A sealing method using a composite seal structure, characterized by the above.

13. A sealing method using the composite seal structure according to claim 12, characterized in that the side of the metal member is in an atmosphere of radical gas.

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