JP5973781B2 - Corrosion-resistant composite seal structure - Google Patents

Description

  The present invention relates to a corrosion-resistant composite seal structure used for semiconductor manufacturing equipment, FPD manufacturing equipment, food-related sterilization equipment, other plasma processing equipment, and the like.

As one of the above-mentioned various uses, for example, as a vacuum pipe joint in an environment where oxygen plasma or oxygen radicals exist, oxygen plasma resistance or oxygen radical resistance and long-term vacuum retention (sealing Sex) is required.
In the conventional oxygen plasma environment or oxygen-resistant radical environment vacuum piping joint 31 illustrated in FIGS. 14 and 15 , a pair of metal couplings 34, 35 to which the connected pipes 32, 33 are integrally coupled, and The seal material 36 is composed of a metal center ring 38 having an arc-shaped recess 37 on the outer peripheral surface and an O-ring 39 fitted to the arc-shaped recess 37.

14 and 15 are clamp type joint seals established in JIS B 8365, which have known shapes and structures, but are shown in the pipes 32 and 33 and the inside 40 of the vacuum pipe joint 31. A corrosive gas (for example, oxygen plasma, oxygen radical) in a vacuum state flows, and the outside 41 is used as, for example, the atmosphere. The vacuum pipe joint 31 for such applications requires vacuum retention (sealability), and as a material for the O-ring 39, a commonly used vinylidene fluoride-based fluororubber called FKM is oxygen. The resistance to plasma and oxygen radicals is low, and in an environment where oxygen plasma and oxygen radicals are present, the surface of the O-ring 39 exposed to plasma or radicals is corroded (etched) and has a sealing property (sealability). Damaged. Therefore, the O-ring 39 has to be replaced frequently because of its short life. Further, although pipe joints having slightly different shapes from those in FIGS. 14 and 15 have been proposed, the above-described problem relating to the corrosion resistance of the O-ring cannot be solved (see, for example, Patent Document 1).

WO2008 / 056743

Therefore, as a material of the O-ring, tetrafluoroethylene-purple chlorovinyl ether-based fluorine rubber called FFKM having plasma resistance and radical resistance is used in an environment in which oxygen plasma or oxygen radical is present. It must be used.
However, FFKM is disadvantageous in that it is expensive and inferior in vacuum retention (compared to FKM) and unsuitable for high vacuum environments.

  Therefore, the present invention has vacuum retention (sealing) and corrosion gas resistance (oxygen plasma resistance, oxygen radical resistance), and its vacuum retention (sealing performance) and corrosion gas resistance (oxygen plasma). It is an object of the present invention to provide a composite seal structure that can maintain long-term performance and oxygen radical resistance). It is another object of the present invention to provide a corrosion-resistant composite seal structure that can use the center ring of JIS B 8365.

In order to achieve the above object, the present invention provides a first space portion, which is interposed between corresponding planes parallel to each other, in which corrosive gas exists, and non-corrosion at a pressure higher than the pressure of the first space portion. A pair of sealing lips that open to form a pressure-receiving concave groove that opens to the second space portion side in a corrosion-resistant composite seal structure that blocks and seals the second space portion where gas exists And an elastic seal integrally having a wedge-shaped protruding portion projecting toward the first space portion, and the wedge-shaped protruding portion is pushed into the second space portion side, and the wedge-shaped protruding portion is pushed into the leg-opening direction. And a corrosion-resistant seal having a pair of sealing lip portions that are in close contact with the corresponding flat surface under the force of the contact, and in the cross-sectional shape, the wedge-shaped protruding portion gradually approaches the first space portion side. And the pair of dense seals of the anti-corrosion seal. The wedge-receiving groove which is formed by use lip is tapered to gradually width to the second space portion side is increased, At a assembled free state, the wedge-shaped突隆portion of the elastic seal The inclined side is configured to be in close contact with the inclined side of the concave groove of the corrosion-resistant seal, and a metal center ring is disposed near the first space, and the center ring A V-shaped groove having a groove bottom small recess is formed on the second space portion side, and the corrosion-resistant seal has a triangular protrusion with a small top protrusion fitted into the V-shaped groove. Is formed.

In addition, a first space portion that is interposed between corresponding parallel planes and in which a corrosive gas exists, and a second space portion in which a non-corrosive gas having a pressure higher than the pressure of the first space portion exists. In a corrosion-resistant composite seal structure that shuts off and seals, a pair of sealing lip portions that open to form a pressure receiving groove that opens to the second space portion side, and the first space portion side. An elastic seal integrally having a protruding wedge-shaped protruding portion and an opening on the second space portion side, and the wedge-shaped protruding portion is pushed to receive a force in the direction of the open leg and receive the force in the corresponding plane. A corrosion-resistant seal having a pair of sealing lip portions that are in close contact with each other, and in the cross-sectional shape, the wedge-shaped protruding portion is formed in a tapered shape that gradually decreases in width toward the first space portion side. And formed by the pair of sealing lip portions of the corrosion-resistant seal. The concave groove for receiving is formed in a taper shape that gradually increases in width toward the second space portion side, and in the free assembly state, the inclined side of the wedge-shaped ridge portion of the elastic seal has the above-mentioned corrosion resistance. One of the corresponding planes parallel to each other is configured to be in close contact with the inclined side of the concave groove of the seal and to be attached to the seal groove having a rectangular cross section. The groove bottom surface corresponds to the groove, and a fitting for receiving the corrosion-resistant seal is fitted to the first space portion side of the seal groove, and the groove bottom is small on the second space portion side of the fitting. A V-shaped groove having a concave portion is formed in the recess, and the anticorrosion seal is formed with a triangular protrusion with a small top protrusion fitted into the V-shaped groove.

In addition, a first space portion that is interposed between corresponding parallel planes and in which a corrosive gas exists, and a second space portion in which a non-corrosive gas having a pressure higher than the pressure of the first space portion exists. In a corrosion-resistant composite seal structure that shuts off and seals, a pair of sealing lip portions that open to form a pressure receiving groove that opens to the second space portion side, and the first space portion side. An elastic seal integrally having a protruding wedge-shaped protruding portion and an opening on the second space portion side, and the wedge-shaped protruding portion is pushed to receive a force in the direction of the open leg and receive the force in the corresponding plane. A corrosion-resistant seal having a pair of sealing lip portions that are in close contact with each other, and in the cross-sectional shape, the wedge-shaped protruding portion is formed in a tapered shape that gradually decreases in width toward the first space portion side. And formed by the pair of sealing lip portions of the corrosion-resistant seal. The concave groove for receiving is formed in a taper shape that gradually increases in width toward the second space portion side, and in the free assembly state, the inclined side of the wedge-shaped ridge portion of the elastic seal has the above-mentioned corrosion resistance. One of the corresponding planes parallel to each other is configured to be in close contact with the inclined side of the concave groove of the seal and to be attached to the seal groove having a rectangular cross section. groove bottom surface of the groove is the case, further, the corrosion resistance seal is a cross-section substantially U-shaped, the groove side surface of the first space portion side of the groove bottom wall portion above the seal groove, is mounted so as to abut Furthermore, the radial total length T _{3 of the} corrosion-resistant seal and the thickness T ₂₉ of the groove bottom wall portion were set to T ₃ × 0.4 ≦ T ₂₉ ≦ T ₃ × 0.7.

In addition, a first space portion that is interposed between corresponding parallel planes and in which a corrosive gas exists, and a second space portion in which a non-corrosive gas having a pressure higher than the pressure of the first space portion exists. In a corrosion-resistant composite seal structure that shuts off and seals, a pair of sealing lip portions that open to form a pressure receiving groove that opens to the second space portion side, and the first space portion side. An elastic seal integrally having a protruding wedge-shaped protruding portion and an opening on the second space portion side, and the wedge-shaped protruding portion is pushed to receive a force in the direction of the open leg and receive the force in the corresponding plane. A corrosion-resistant seal having a pair of sealing lip portions that are in close contact with each other, and in the cross-sectional shape, the wedge-shaped protruding portion is formed in a tapered shape that gradually decreases in width toward the first space portion side. And formed by the pair of sealing lip portions of the corrosion-resistant seal. The concave groove for receiving is formed in a taper shape that gradually increases in width toward the second space portion side, and in the free assembly state, the inclined side of the wedge-shaped ridge portion of the elastic seal has the above-mentioned corrosion resistance. It is constructed so as to be in close contact with the inclined side of the concave groove of the seal, and a metal center ring is disposed near the first space portion, and the center ring is recessed in the shape of a circular arc on the second space portion 2 side. In the center ring of JIS B 8365 having a groove, the corrosion-resistant seal is formed with an arcuate protrusion that is fitted into the arcuate groove having a cross-section.

In the free state, the outer end width of the pair of lip portions of the elastic seal was set larger than the outer end width of the pair of lip portions of the corrosion resistant seal.

  Moreover, it has the small protrusion part for the local surface pressure rise which contacts the said corresponding plane and elastically deforms at the front-surface front-end | tip part of a pair of lip | rip part of the said elastic seal.

According to the corrosion-resistant composite seal structure according to the present invention, the corrosion-resistant seal can prevent the corrosive gas from the first space portion from coming into contact with the elastic seal, and the elastic seal can be removed from the second space portion. It is possible to prevent the entry of non-corrosive gas (such as the atmosphere), and each seal can perform each function (function) to the maximum.
Since the elastic seal is not deteriorated by the corrosive gas, the sealing performance such as vacuum retention can be exhibited over a long period of time.

It is sectional drawing of the decomposition | disassembly state which shows the 1st Embodiment of this invention. It is sectional drawing of a center ring. It is sectional drawing of the corrosion-resistant seal | sticker of a decomposition free state. It is sectional drawing of the elastic seal of a decomposition free state. It is a principal part expanded sectional view which shows a free state. It is a principal part expanded sectional view which shows a compression use state. It is a principal part expanded sectional view of the free state which shows 2nd Embodiment. It is a principal part expanded sectional view of the free state which shows 3rd Embodiment. It is a principal part expanded sectional view of the free state which shows 4th Embodiment. It is a principal part expanded sectional view of a compression use state. It is sectional drawing of the center ring of 5th Embodiment. It is sectional drawing of the corrosion-resistant seal | sticker of a decomposition free state. It is a principal part expanded sectional view which shows a free state. It is sectional drawing of the decomposition | disassembly state which shows a prior art example. It is an expanded sectional view of the principal part of a prior art example, Comprising: (A) is an expanded sectional view of a free state, (B) is an expanded sectional view of a compression use state.

Hereinafter, the present invention will be described in detail with reference to the drawings illustrating embodiments.
In the first embodiment shown in FIGS. 1 to 6, a corrosion-resistant composite seal structure S according to the present invention is interposed between corresponding planes 11 and 12 parallel to each other, and oxygen plasma, The first space 1 in which a corrosive gas (gas) such as oxygen radicals is present and the second space 2 in which a non-corrosive gas having a pressure higher than the pressure of the first space 1 is shut off and sealed. This is a seal configuration.
Specifically, in FIG. 1, a clamp-type pipe joint seal structure is illustrated, and the shaft center of the outer flange portion of a pair of metal couplings 4 and 5 to which the pipes 32 and 33 to be connected are coupled together is illustrated. The orthogonal end faces 4A and 5A correspond to the corresponding parallel planes 11 and 12 described above.

Reference numeral 8 denotes a metal center ring, which includes a thin short tube portion 8A and a protruding portion 8B that protrudes radially outward from the center of the outer peripheral surface thereof.
The first space portion 1 is formed by the inside of the cylindrical couplings 4 and 5 and the inside of the center ring 8, and corrosive gas such as oxygen plasma and oxygen radical flows. The 2nd space part 2 is air | atmosphere, for example, and the 1st space part 1 is what is called a vacuum pressure whose pressure is lower than air | atmosphere.

A V-shaped groove 9 is formed in the protruding portion 8B of the center ring 8, and a small rectangular recess 10 is formed at the back of the V-shaped groove 9 (FIGS. 2, 5, etc.). reference). That is, a center ring 8 is arranged near the first space 1 in the radial inner direction, and the groove bottom small concave portion 10 is formed on the second space 2 side of the center ring 8 in the radial outward direction. The V-shaped groove 9 is formed, and the corrosion-resistant seal 3 is fitted into the V-shaped groove 9. Further, an elastic seal 6 is disposed radially outward of the corrosion-resistant seal 3. ing.

The elastic seal 6 has a pressure receiving groove 7 that opens to the radial outer side --- the second space 2 side--. In other words, the pair of sealing lip portions 13 and 13 are extended to the second space portion 2 side in an open leg shape, and the pressure receiving groove 7 is formed therebetween.
Further, the elastic seal 6 integrally has a wedge-shaped protruding portion 14 protruding in the radial inward direction --- the first space portion 1 side.

The corrosion-resistant seal 3 is a pair of sealing lips that open in the radial outward direction—the second space 2 side—and the wedge-shaped ridge 14 is pushed to receive a force in the direction of the legs. Parts 15 and 15. That is, the corrosion-resistant seal 3 has a concave groove 16 that is radially outwardly formed by the pair of sealing lip portions 15 and 15 and receives the force in the above-described opening direction, The lip portions 15 and 15 are in close contact with 12 (see FIG. 6).

In the cross-sectional shape, the wedge-shaped protruding portion 14 is formed in a tapered shape in which the width dimension W ₁₄ gradually decreases toward the first space portion 1 (inward in the radial direction). Further, the radially inward end surface 14A of the wedge-shaped protruding portion 14 is formed into a flat surface, and substantially parallel portions 14B and 14B are formed at the base of the wedge-shaped protruding portion 14, as shown in FIG. On the left side of the position indicated by the two-dot chain line L ₁₄ is a wedge-shaped ridge ₁₄ having a substantially trapezoidal shape with the two-dot chain line L ₁₄ as the bottom and the tip surface 14A as the upper side. It can be said that it is a substantially hexagonal shape in which substantially parallel portions 14B and 14B are formed by slightly cutting the left and right corners of the base. Thus, the wedge-shaped ridge 14 has the inclined sides 14C and 14C.

On the other hand, as shown in the cross-sectional shape of FIG. 3, the wedge-receiving concave groove 16 into which the wedge-shaped protruding portion 14 is pushed by the pair of sealing lip portions 15, 15 of the corrosion-resistant seal 3 is It is formed in a taper shape in which the width dimension W ₁₆ gradually increases toward the second space 2 side (radial outward direction). More specifically, the groove bottom portion 16A of the concave groove 16 is formed in a straight shape (or a small arc shape not shown), and substantially parallel portions 16B and 16B are formed at the opening end of the concave groove 16. Has been. Thus, the overall cross-sectional shape of the groove 16, said the two-dot chain line L ₁₆ from substantially trapezoidal to bottom, substantially parallel portions 16B cut away the left and right corners of the bottom side, and a substantially hexagon forming the 16B . In this way, the wedge-receiving concave groove 16 has the inclined sides 16C and 16C.

  In the assembly free state shown in FIG. 5, the inclined sides (tapered surfaces) 14C, 14C of the elastic seal 6 are closely connected to the inclined sides (tapered surfaces) 16C, 16C of the concave groove 16 of the corrosion resistant seal 3. When the lip portions 15 and 15 of the corrosion resistant seal 3 are subjected to the pressing force (external force) from the corresponding flat surfaces 11 and 12 in the compression use state after contact (see FIG. 6), the elastic compression deformation is caused. The elastic ridges 14 of the elastic seal 6 pushed into the grooves 16 are also elastically deformed, and the lip portions 15 and 15 are expanded (open legs) in a direction in which a large elastic urging force is applied (elastic restoration) Power).

  In other words, the inclined sides 14C, 14C of the wedge-shaped ridge 14 are strongly and elastically pressed against the inclined sides 16C, 16C of the concave groove 16 of the corrosion-resistant seal 3 to expand the lip portions 15, 15 ( Generating a large elastic urging force (elastic restoring force) in the direction of opening the legs, thereby increasing the sealing surface pressure against the corresponding flat surfaces 11 and 12 of the sealing lip portions 15 and 15 of the corrosion-resistant seal 3 it can.

By the way, in the disassembly free state, the angle θ ₁₄ formed by the inclined sides 14C and 14C of the wedge-shaped ridge ₁₄ and the angle θ ₁₆ formed by the inclined sides 16C and 16C of the concave groove ₁₆ are 15 ° to 120 °. °. The angle is preferably 30 ° to 110 °, and more preferably 60 ° to 100 ° (see FIGS. 3 and 4).

In the state of FIG. 6, the elastic seal 6 receives the gas pressure from the second space 2 and the first space 1.
The wedge-shaped ridge 14 is pushed deeper into the groove 16 (inward in the radial direction) by the pressing force, and the lip portion 15 with respect to the corresponding flat surfaces 11 and 12 described above is pressed. , 15 surface pressure increases.

By the way, the shape of the corrosion-resistant seal 3 on the first space 1 side (radial inward side) will be described. As shown in FIGS. A triangular protrusion 18 with a small top protrusion 17 is formed, and this small protrusion 17 is fitted in a small recess 10 of the center ring 8 as shown in FIG. 5 and FIG. Assembled.

As shown in FIG. 3, the outer base end portions 19 and 19 of the pair of sealing lip portions 15 and 15 of the corrosion-resistant seal 3 are continuously inclined with the inclined surface of the triangular protrusion 18 in the disassembly free state. Although drawn in a line, the outer surface tip 20 at an angle θ ₂₀ (on the straight lines L ₂₀ and L ₂₀ ) sufficiently smaller than the angle θ ₁₉ formed by the outer surface base ends 19 and 19 of the lip portions 15 and 15. , 20 are continuous via the corner 21.

In this way, mutual width W ₂₀ of the outer surface tip portions 20 of the pair of the lip portions 15 and 15, the second
In the compression use state shown in FIG. 6, the seal contact surface 22 that contacts the corresponding flat surfaces 11 and 12 is formed with a corrosive gas blocking width W ₂₂ . It is a large plane. Thereby, the sealing performance of the elastic seal 6 can be maintained over a long period of time, and a long-life seal structure is obtained.

Further, as shown in the disassembly free state of FIGS. 3 and 4 and the free mounting state of FIG. 5, the elastic seal is larger than the outer end width W ₁₅ of the pair of lip portions 15 and 15 of the corrosion resistant seal 3. the outer end width W ₁₃ of the pair of lip portions 13, 13 of 6 large set, to enhance the seal surface pressure for sealing the non-corrosive gas in the second space 2.

The elastic seal 6 will be further described. In the first embodiment shown in FIGS. 1 to 6 and other embodiments such as FIGS. 8 to 10 and FIG. 13 described later, the pair of lip portions 13 and 13 are provided. The outer surface tip 23 has a small protrusion 24 for increasing the local surface pressure that is elastically compressed and deformed in contact with the corresponding flat surfaces 11 and 12.
In the second embodiment shown in FIG. 7, the small projecting portion 24 is omitted, and the outer surface tip portion 23 of the lip portions 13 and 13 is formed in a gradient straight shape. If the seal surface pressure can be secured when pressed against the corresponding flat surfaces 11 and 12, the shape shown in FIG. 7 can be freely used. Note that FIG. 7 has almost the same configuration as that of FIG. 5, and thus the description thereof will be omitted (the same reference numerals are the same).

Next, in the third embodiment shown in FIG. 8, a case of so-called flange fixing or the like is illustrated (in contrast to the clamp-type pipe joint seal described in FIGS. 1 to 7). In other words, it is used to seal between the mounting member 26 having the sealing groove 25 having a rectangular cross section and the mating member 27 opposed to each other in plan view.
That is, the corrosion-resistant seal 3, the elastic seal 6, and the substantially U-shaped receiving metal fitting 28 (in place of the above-described center ring 8) are fitted into the seal groove 25 having a rectangular cross section. One of the corresponding flat surfaces 11 and 12 of the above-described embodiment parallel to each other corresponds to the groove bottom surface 25A of the seal groove 25, and the other of the corresponding flat surfaces 11 and 12 corresponds to the flat surface of the mating member 27. Applicable.

More specifically, a receiving metal fitting 28 is fitted on the first groove 1 side of the seal groove 25 in order to receive the corrosion-resistant seal 3.
The receiving metal fitting 28 is provided with a V-shaped groove 9 having a groove bottom small recess 10 on the second space 2 side (that is, the center ring 8 of the first and second embodiments described above). In part).

And the cross-sectional shape of the corrosion-resistant seal | sticker 3 is the same as that of FIGS. That is, the corrosion-resistant seal 3 has a triangular protrusion 18 with a small top protrusion 17 that is fitted in the V-shaped groove 9 of the metal fitting 28.
The shape of the triangular protrusion 18 and the shape of the V-shaped groove 9 are the same as those shown in FIGS.

  Next, in the fourth embodiment shown in FIGS. 9 and 10, the place of use is the same as in FIG. 8, and the mounting member 26 having the rectangular cross-sectional seal groove 25 is omitted (the metal fitting 28 in FIG. 8 is omitted). Then, only the corrosion-resistant seal 3 and the elastic seal 6 are fitted (attached). That is, one of the corresponding flat surfaces 11 and 12 corresponds to the groove bottom surface 25A, and the other corresponds to the flat surface of the mating member 27.

The corrosion-resistant seal 3 itself has a cross-sectional shape that can maintain a stable posture in the rectangular seal groove 25. That is, the corrosion-resistant seal 3 has a substantially U-shaped cross section, but the thickness T ₂₉ of the groove bottom portion ₂₉ is large. For example, the thickness T ₂₉ is 40% to 70% of the radial total length T ₃ . Moreover, the groove bottom portion 29 has a rectangular cross section and is mounted so as to abut on the groove side surface 25B of the seal groove 25 on the first space portion 1 side.
In the fourth embodiment shown in FIGS. 9 and 10, the metal fitting 28 in the third embodiment shown in FIG. 8 is made of the same material as the corrosion-resistant seal 3, and both are completely integrated. It can also be said that the shape has been changed.

11 to 13 show a fifth embodiment. A metal center ring 8 is disposed near the first space 1, and the center ring 8 is a JIS B 8365 center ring having an arc-shaped groove 49 in cross section on the second space 2 side. The corrosion-resistant seal 3 is formed with an arcuate protrusion 50 that is fitted in the arcuate groove 49 in cross section. The curvature radius R ₅₀ of the cross-sectional outer arc of the arc-shaped protrusion 50 is set to be the same as or slightly smaller than the curvature radius R ₄₉ of the arc-shaped concave groove 49 of the cross-section. Other configurations are the same as those of the first embodiment.

  In the present invention, the sealing lip portions 13 and 13 of the elastic seal 6 are bent at the corner portions 42 (in the shape of the outer surface) at the corner portions 42, and more than the corner portions 42. A small concave recess 43 is formed in the vicinity of the proximal end. The small concave recess 43 has a surface substantially perpendicular to the above-described substantially parallel portion 14B and the corresponding flat surfaces 11 and 12, but has a shape to which an appropriate radius portion is added. The tip portion 15A on the second space 2 side of the lip portion 15 of the corrosion resistant seal 3 is substantially parallel to the corresponding flat surfaces 11, 12, and has the outer surface tip portion 20, the most advanced surface 15B, and a substantially parallel portion 16B. While being configured in a rectangular shape (as shown in FIGS. 5 to 10, 12, and 13), the rectangular tip portion 15 </ b> A is fitted (partially) into the small concave recess 43 of the elastic seal 6. Match. By such fitting, the elastic repulsion biasing force accompanying the elastic compression of the elastic seal 6 acts strongly (in the vertical direction in FIGS. 6 and 10), and the leading edge of the outer surface tip 20 of the corrosion resistant seal 3. The part is assisted (reinforced) so as to be in close contact with the corresponding planes 11 and 12 with a large surface pressure.

By the way, in the elastic seal 6, the sealing lip portions 13, 13 are free of the portion (outer surface tip portion 23) to be pressed against the corresponding flat surfaces 11, 12 under the compression use condition as shown in FIGS. 6 and 10. width W ₂₃ under condition (FIGS. 5, 7, 8, 9, see FIG. 13) is set larger than the distance dimension G ₀ of the corresponding planes 11 and 12 under compression use.
That includes a corner portion 42, the width W ₂₃ of the outer surface tip portion 23, is set larger than the spacing dimension G _0, plus the seal surface pressure by the sealing lip 13, the corner portion 42 elastically The seal surface pressure can be further increased by the dynamic compression deformation.

As the material for the corrosion-resistant seal 3, silicone rubber, polyether ether ketone (PEEK), polyimide (PI), tetrafluoroethylene resin (PTFE), or perfluoroelastomer (FFKM) are suitable. Moreover, as a material of the elastic seal 6,
Fluoro rubber, ethylene-propylene rubber, nitrile rubber, or hydrogenated nitrile rubber,
Alternatively, vinylidene fluoride (FKM) rubber is used. In the present invention, F is expensive as a material.
The first space portion 1 where oxygen plasma, oxygen radicals, etc. are present without using FKM (tetrafluoroethylene-purple chlorovinyl ether-based fluororubber) or only using a smaller amount of FFKM than in the past, for example, The second space 2 in which the atmosphere (non-corrosive gas) exists can be manufactured at low cost and can be hermetically sealed for a long period.

The present invention is not limited to the embodiment shown in the drawings, and the design can be freely changed. The inside and the outside in the radial direction may be interchanged. That is, the second space portion 2 is set to the radially inner side such as the inside of the pipe, and the first space portion 1 is set to the radially outer side such as the outside of the pipe, so that the grooves 16 of the corrosion resistant seal 3 and the elastic seal 6 are provided. It is also possible to arrange 7 so that it faces radially inward.
Alternatively, the present invention is not limited to vacuum use, and can be freely applied if the pressure in the second space 2 is higher than that in the first space 1. Further, the cross-sectional shapes of the center ring 8 (see FIG. 1) and the receiving metal fitting 28 (see FIG. 8) can be variously modified other than shown. Further, the overall shape of the corrosion-resistant seal 3, the elastic seal 6, the receiving metal fitting 28 (see FIG. 8) and the like is not limited to an annular shape, but may be a polygon such as a rectangle or an annular shape such as an ellipse.

As described above, the present invention is interposed between the corresponding planes 11 and 12 parallel to each other, and the first space portion 1 where the corrosive gas exists, and the non-pressure higher than the pressure of the first space portion 1 are present. In the corrosion-resistant composite seal structure that blocks and seals the second space portion 2 where the corrosive gas exists; a pair of legs that open to form a pressure-receiving concave groove 7 that opens to the second space portion 2 side. An elastic seal 6 integrally having sealing lip portions 13 and 13 and a wedge-shaped protruding portion 14 protruding toward the first space portion 1 side; and a wedge-shaped protruding portion opening toward the second space portion 2 side And a corrosion-resistant seal 3 having a pair of sealing lip portions 15 and 15 that are pressed into the corresponding flat surfaces 11 and 12 by receiving a force in the direction of opening and being pressed, elastic seal 6 is pushed by the wedge突隆portion 14 in pressure-receiving state to the groove 16 of the anti-corrosion sealing 3 sealing lip 15, 15 However, it is possible to prevent the elastic seal 6 from being damaged by the corrosive gas by closely contacting the corresponding flat surfaces 11 and 12 with a high surface pressure and blocking the corrosive gas. Then, the elastic seal 6 receives pressure in the pressure receiving groove 7 and the sealing lip portions 13 and 13 are elastically deformed in the direction to open the legs, and are brought into close contact with the corresponding flat surfaces 11 and 12 with high surface pressure. The gas flow from the space portion 1 to the second space portion 2 is reliably blocked.
In this way, both seals 3 and 6 perform different functions and functions, and each is expensive F
Without using a material such as FKM, sealing performance (sealing performance) and durability can be reliably exhibited.
To reiterate, the corrosion-resistant seal 3 can prevent the corrosive gas such as oxygen plasma and oxygen radicals from flowing to the elastic seal 6, and the elastic seal 6 is not deteriorated by the corrosive gas. Can be maintained over a long period of time, and dust generation of the elastic seal 6 due to such deterioration can be prevented, so that impurities are not attached to the products in the semiconductor manufacturing apparatus and the FPD manufacturing apparatus.

Further, At a free state, the outer end width W ₁₅ of the pair of lip portions 15, 15 of corrosion-resistant seals 3, the outer end width W ₁₃ of the pair of lip portions 13, 13 of the elastic seal 6 Since it set large, the said sealing performances, such as a vacuum holding property, can be improved further.

Further, in the cross-sectional shape, the wedge-shaped protruding portion 14 is formed in a taper shape in which the width dimension W ₁₄ gradually decreases toward the first space portion 1 side, and a pair of sealing lips of the corrosion resistant seal 3 is formed. The groove 16 for receiving the wedge formed by the portions 15 and 15 is formed in a taper shape in which the width dimension W ₁₆ is gradually increased toward the second space portion 2 side, so that the elastic force rich in elastic urging force is provided. The seal 6 cleverly spreads the corrosion-resistant seal 3 from the inner side in the direction of the legs, and reliably exerts the functions and functions of the corrosion-resistant seal 3.

Further, At a free state, mutual width W ₂₀ of the outer surface tip portions 20 of the pair of sealing lip 15, 15 of corrosion-resistant seal 3, so that gradually increases to the second space portion 2 Since the seal contact surface 22 that contacts the corresponding flat surfaces 11 and 12 in a compression use state is a flat surface having a large corrosive gas blocking width W ₂₂ , for example, oxygen plasma, oxygen radical Therefore, the sealing performance of the elastic seal 6 can be maintained over a long period of time. Alternatively, the elastic seal 6 does not need to be made of an expensive material.

Further, a metal center ring 8 is disposed near the first space 1, and the center ring 8
A V-shaped groove 9 having a groove bottom small recess 10 is formed in the second space 2 side, and a top small protrusion 17 fitted into the V-shaped groove 9 is provided in the corrosion-resistant seal 3. Since the attached triangular protrusion 18 is formed, the center ring 8 and the corrosion-resistant seal 3 are fitted (assembled) in a stable posture, have excellent seal mounting properties, and are in use. The postures of the seals 3 and 6 are always stable.

  In addition, one of the corresponding flat surfaces 11 and 12 that are configured to be attached to the seal groove 25 having a rectangular cross section corresponds to the groove bottom surface 25A of the seal groove 25. A receiving metal fitting 28 that receives the corrosion-resistant seal 3 is fitted on the first space 1 side, and a V-shaped groove 9 having a groove bottom small recess 10 is recessed on the second space 2 side of the receiving metal 28. The corrosion-resistant seal 3 is provided with a triangular protrusion 18 with a small top protrusion 17 fitted in the V-shaped groove 9 and is suitable for a flange or an opening / closing lid. Further, the metal fitting 28 and the corrosion-resistant seal 3 are fitted (assembled) with a stable posture to each other, have excellent seal mounting properties, and the postures of the seals 3 and 6 are always stable in use. (See FIG. 8).

Further, one of the corresponding flat surfaces 11 and 12 which are configured to be attached to the seal groove 25 having a rectangular cross section corresponds to the groove bottom surface 25A of the seal groove 25, and further, a corrosion resistant seal. 3 is a substantially U-shaped section having a large thickness T ₂₉ of the groove bottom wall portion 29, and the groove bottom wall portion 29 is in contact with the groove side surface 25 B on the first space 1 side of the seal groove 25. Since it is mounted, the number of parts can be reduced (as shown in FIG. 9), and the structure can be simplified. Moreover, the corrosion resistant seal 3 maintains a stable posture in the seal groove 25. This structure can be said to be suitable for a flange or an opening / closing lid.

Further, a metal center ring 8 is disposed near the first space portion 1 so that the center ring 8 is the second space.
A center ring of JIS B 8365 having a circular arc-shaped groove 49 in the space 2 side, and the corrosion-resistant seal 3 is formed with an arc-shaped protrusion 50 fitted in the circular arc-shaped groove 49 in the cross section. Therefore, it is convenient to use the center ring of JIS B 8365 (as shown in Fig. 13). That is, the vacuum retaining property and the corrosion gas resistance can be obtained simply by replacing the O-ring conventionally used with JIS B 8365 with the corrosion resistant seal 3 and the elastic seal 6 of the present invention (fifth embodiment). It is possible to provide a composite seal structure that can maintain the vacuum retention and corrosion gas resistance for a long time.

The corrosion-resistant seal 3 is made of silicone rubber, polyether ether ketone, polyimide, tetrafluoroethylene resin, or perfluoroelastomer, and the elastic seal 6 is fluorine rubber, ethylene-propylene rubber, nitrile rubber. Or a hydrogenated nitrile rubber or a vinylidene fluoride (FKM) rubber, so that the corrosion-resistant seal 3
Is excellent in oxygen-resistant plasma and oxygen-resistant radical properties, can prevent deterioration, and maintains the sealing properties such as vacuum retention of the elastic seal 6 for a long period of time. Furthermore, the elastic seal 6 is further sealed (elasticity).
Can be maintained over the long term. In addition, it is not necessary to use an expensive material such as the FFKM as the composite seal, or only a small amount of the conventional seal is required.

Further, the width dimension W ₂₃ under the free state of the portion where the sealing lip portions 13 and 13 of the elastic seal 6 should be in pressure contact with the corresponding planes 11 and 12 is the gap dimension G ₀ between the corresponding planes 11 and 12 under the compression use condition. Therefore, a higher surface pressure is generated by the elastic compression deformation (crushing) accompanying the approach of the corresponding flat surfaces 11 and 12, and the sealing performance of the elastic seal 6 is further improved.

  In addition, since the outer surface tip 23 of the pair of lip portions 13 and 13 of the elastic seal 6 has a small protrusion 24 for increasing the local surface pressure that elastically compresses and deforms in contact with the corresponding flat surfaces 11 and 12, the local surface Pressure is increased and further sealing performance is improved.

DESCRIPTION OF SYMBOLS 1 1st space part 2 2nd space part 3 Corrosion-resistant seal 6 Elastic seal 7 Pressure receiving groove 8 Center ring 9 V-shaped groove
10 Small recess
11, 12 Compatible plane
13 Sealing lip
14 Wedge shaped ridge
15 Sealing lip
15A tip
16 groove
17 Small top protrusion
18 Triangular protrusion
19 Outer base end
20 External tip
22 Seal contact surface
23 Tip of outer surface
24 Small protrusion
25 Seal groove
25A groove bottom
25B groove side
28 Bracket
29 Groove bottom
49 Cross-section arc-shaped groove
50 Arc-shaped protrusion T ₂₉ Thickness W ₁₄ , W ₁₆ , W ₂₃ Width W ₂₀ Mutual width W ₂₂ Corrosion gas cutoff width W ₁₃ , W ₁₅ Outer end width G ₀ Distance

Claims (6)

A first space part (1) interposed between corresponding parallel planes (11) and (12) parallel to each other, and a non-corrosion having a pressure higher than the pressure of the first space part (1). In the corrosion-resistant composite seal structure that shuts off and seals the second space (2) where gas exists,
A pair of sealing lip portions (13) and (13) that open to form a pressure receiving groove (7) that opens to the second space portion (2) side, and to the first space portion (1) side. An elastic seal (6) integrally having a protruding wedge-shaped protrusion (14);
A pair of seals that open to the second space (2) side and are in close contact with the corresponding flat surfaces (11) and (12) when the wedge-shaped ridges (14) are pushed and receive a force in the direction of the legs. A corrosion resistant seal (3) having a lip (15) (15) for use;
Equipped with,
In the cross-sectional shape, the wedge-shaped ridge (14) is formed in a taper shape in which the width dimension (W ₁₄ ) gradually decreases toward the first space (1) , and the corrosion-resistant seal ( 3) The wedge receiving concave groove (16) formed by the pair of sealing lip portions (15) and (15) in (3) gradually increases in width dimension (W ₁₆ ) toward the second space portion (2). In the assembly free state, the inclined sides (14C) (14C) of the wedge-shaped ridge (14) of the elastic seal (6) are recessed in the corrosion-resistant seal (3). It is constructed so as to be in close contact with the inclined side (16C) (16C) of the groove (16),
A metal center ring (8) is disposed near the first space (1), and the groove bottom small recess (10) is provided on the second space (2) side of the center ring (8). A V-shaped groove (9) having a recess is provided, and the corrosion-resistant seal (3) has a triangular protrusion with a small top protrusion (17) fitted in the V-shaped groove (9). (18) are formed corrosion resistant composite sealing structure according to claim Rukoto. A first space part (1) interposed between corresponding parallel planes (11) and (12) parallel to each other, and a non-corrosion having a pressure higher than the pressure of the first space part (1). In the corrosion-resistant composite seal structure that shuts off and seals the second space (2) where gas exists,
A pair of sealing lip portions (13) and (13) that open to form a pressure receiving groove (7) that opens to the second space portion (2) side, and to the first space portion (1) side. An elastic seal (6) integrally having a protruding wedge-shaped protrusion (14);
A pair of seals that open to the second space (2) side and are in close contact with the corresponding flat surfaces (11) and (12) when the wedge-shaped ridges (14) are pushed and receive a force in the direction of the legs. A corrosion resistant seal (3) having a lip (15) (15) for use;
Comprising
In the cross-sectional shape, the wedge-shaped ridge (14) is formed in a taper shape in which the width dimension (W ₁₄ ) gradually decreases toward the first space (1) , and the corrosion-resistant seal ( 3) The wedge receiving concave groove (16) formed by the pair of sealing lip portions (15) and (15) in (3) gradually increases in width dimension (W ₁₆ ) toward the second space portion (2). In the assembly free state, the inclined sides (14C) (14C) of the wedge-shaped ridge (14) of the elastic seal (6) are recessed in the corrosion-resistant seal (3). It is constructed so as to be in close contact with the inclined side (16C) (16C) of the groove (16),
In addition, one of the corresponding flat surfaces (11) and (12) parallel to each other is configured to be attached to the seal groove (25) having a rectangular cross section, and the bottom surface (25A) of the seal groove (25) And a fitting (28) for receiving the corrosion-resistant seal (3) is fitted on the first space (1) side of the seal groove (25), and the fitting (28) A V-shaped groove (9) having a small groove bottom concave portion (10) is recessed in the second space portion (2) side, and the corrosion-resistant seal (3) has the V-shaped groove ( 9) A corrosion-resistant composite seal structure characterized in that a triangular protrusion (18) with a top small protrusion (17) fitted to 9) is formed . A first space part (1) interposed between corresponding parallel planes (11) and (12) parallel to each other, and a non-corrosion having a pressure higher than the pressure of the first space part (1). In the corrosion-resistant composite seal structure that shuts off and seals the second space (2) where gas exists,
A pair of sealing lip portions (13) and (13) that open to form a pressure receiving groove (7) that opens to the second space portion (2) side, and to the first space portion (1) side. An elastic seal (6) integrally having a protruding wedge-shaped protrusion (14);
A pair of seals that open to the second space (2) side and are in close contact with the corresponding flat surfaces (11) and (12) when the wedge-shaped ridges (14) are pushed and receive a force in the direction of the legs. A corrosion resistant seal (3) having a lip (15) (15) for use;
Comprising
In the cross-sectional shape, the wedge-shaped ridge (14) is formed in a taper shape in which the width dimension (W ₁₄ ) gradually decreases toward the first space (1), and the corrosion-resistant seal ( 3) The wedge receiving concave groove (16) formed by the pair of sealing lip portions (15) and (15) in (3) gradually increases in width dimension (W ₁₆ ) toward the second space portion (2). In the assembly free state, the inclined sides (14C) (14C) of the wedge-shaped ridge (14) of the elastic seal (6) are recessed in the corrosion-resistant seal (3). It is constructed so as to be in close contact with the inclined side (16C) (16C) of the groove (16),
In addition, one of the corresponding flat surfaces (11) and (12) parallel to each other is configured to be attached to the seal groove (25) having a rectangular cross section, and the bottom surface (25A) of the seal groove (25) In addition, the corrosion-resistant seal (3) has a substantially U-shaped cross section, and the groove bottom (29) is a groove on the first space (1) side of the seal groove (25). Attached to the side surface (25B) to be in contact with each other, and further, the radial total length dimension (T ₃ ) of the corrosion-resistant seal ( ₃ ) and the wall thickness dimension (T ₂₉ ) of the groove bottom wall part (29) , A corrosion-resistant composite seal structure characterized in that T ₃ × 0.4 ≦ T ₂₉ ≦ T ₃ × 0.7 . A first space part (1) interposed between corresponding parallel planes (11) and (12) parallel to each other, and a non-corrosion having a pressure higher than the pressure of the first space part (1). In the corrosion-resistant composite seal structure that shuts off and seals the second space (2) where gas exists,
A pair of sealing lip portions (13) and (13) that open to form a pressure receiving groove (7) that opens to the second space portion (2) side, and to the first space portion (1) side. An elastic seal (6) integrally having a protruding wedge-shaped protrusion (14);
A pair of seals that open to the second space (2) side and are in close contact with the corresponding flat surfaces (11) and (12) when the wedge-shaped ridges (14) are pushed and receive a force in the direction of the legs. A corrosion resistant seal (3) having a lip (15) (15) for use;
Comprising
In the cross-sectional shape, the wedge-shaped ridge (14) is formed in a taper shape in which the width dimension (W ₁₄ ) gradually decreases toward the first space (1) , and the corrosion-resistant seal ( 3) The wedge receiving concave groove (16) formed by the pair of sealing lip portions (15) and (15) in (3) gradually increases in width dimension (W ₁₆ ) toward the second space portion (2). In the assembly free state, the inclined sides (14C) (14C) of the wedge-shaped ridge (14) of the elastic seal (6) are recessed in the corrosion-resistant seal (3). It is constructed so as to be in close contact with the inclined side (16C) (16C) of the groove (16),
Further, a metal center ring (8) is disposed near the first space (1), and the center ring (8) has an arc-shaped groove (49) in cross section on the second space 2 side. The anti-corrosion seal (3) has an arc-shaped protrusion (50) fitted into the arc-shaped groove (49) in cross section. Corrosive composite seal structure. In a free state, the pair of lip portions (13) of the elastic seal (6) is larger than the outer end width (W ₁₅ ) of the pair of lip portions (15) (15) of the corrosion resistant seal (3). The corrosion-resistant composite seal structure according to claim 1, 2, 3 or 4 , wherein the outer end width dimension (W ₁₃ ) of ( ₁₃ ) is set large . For increasing the local surface pressure that elastically compresses and deforms in contact with the corresponding flat surfaces (11) and (12) at the outer surface tip portions (23) of the pair of lip portions (13) and (13) of the elastic seal (6) The corrosion-resistant composite seal structure according to claim 1, 2 , 3 , 4, or 5 having a small protrusion (24) .

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