JP2002130481A - Seal ring - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a seal ring capable of being set in dovetail grooves easily and excellent in the sealing function. SOLUTION: The seal ring 10 to seal a joining place of two members in such a way as set in dovetail grooves formed in either member and abutting to the other member, is made in a ring form from an elastically deformable material, having such a cross-section as equipped with projections 12a, 12b, 12c arranged protruding in three directions at the periphery and recesses 14a, 14b, 14c provided between them 12a, 12b, 12c.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealing ring, and more particularly, to a sealing ring which is mounted on a joint between members in a piping device or the like which requires high airtightness to seal the joint. It is targeted.

[0002]

2. Description of the Related Art A sealing ring such as an O-ring is attached to a joint between flanges of a pipe valve to maintain airtightness at the joint. The sealing ring is made of an annular body formed of rubber or synthetic resin having excellent elasticity.
Form an annular insertion groove on one side of the flange at the joint,
The sealing ring is inserted into the insertion groove. When the flange on the other side is brought into contact with the sealing ring and the flanges are closed, the sealing ring comes into contact with the flange on the other side and is elastically deformed, thereby fulfilling the sealing function.

The insertion groove of the sealing ring is generally a rectangular groove, but an insertion groove having a dovetail structure is also known. The dovetail groove means a groove structure in which the back side is wider than the opening side. It is said that when the sealing ring is inserted into the dovetail groove, the sealing ring does not easily come off from the groove and has an excellent sealing function during use. In particular, in applications where the joint is repeatedly opened and closed, it is effective to use a dovetail to prevent the sealing ring from coming off. The cross-sectional shape of the sealing ring greatly affects the performance of the sealing ring such as a sealing function. It is said that the above-mentioned O-ring has a circular cross section, is easy to manufacture, and has excellent elastic deformability.

As a specific example of a sealing ring suitable for mounting in the above-described dovetail groove, Japanese Patent Application Laid-Open No. 10-318373 discloses a sealing ring having a heart-shaped cross section. Specifically, a concave part is provided on a part of the circumference of the basic circular cross section, and both sides of the concave part are leg-shaped. The shape formed by the concave portion and the leg portion is arranged along the inner shape of the dovetail groove, and the leg portion comes into contact with and adheres to the bottom of the dovetail groove. As a result, it is said that the sealing ring can be mounted uniformly over the entire length in a stable posture without twisting or rolling inside the dovetail groove. It is also said that the presence of the concave portion allows the repulsion elastic force to act favorably and enhance the sealing function.

[0005]

However, the above-mentioned sealing ring having a heart-shaped cross section requires time and skill in the work of mounting it in the dovetail groove, and also has an insufficient sealing function. First, the sealing ring having a heart-shaped cross section must be inserted so that the concave portion and the leg portions on both sides are inserted into the inside of the dovetail groove from the opening and the leg portion contacts the bottom surface of the dovetail groove. Must. It is difficult to push the leg-shaped portion, which is considerably wider than the dovetail groove opening and spreads left and right, into the inside without being caught in the dovetail groove opening. In the case of an O-ring, the tip of the arc-shaped outer peripheral surface hits the opening of the dovetail groove. Therefore, if the O-ring is pushed as it is, the O-ring is elastically deformed and pushed inside.
However, in the case of a sealing ring having a heart-shaped cross section, the leg-like portion cannot be inserted into the opening of the dovetail groove unless the leg-like portion is strongly sandwiched from the left and right to make the width sufficiently small. Performing this operation manually requires considerable familiarity and skill. It is impossible to insert the leg-shaped portion into the opening while keeping the leg portion thin with fingers or the like.

In a small heart-shaped sealing ring, it is difficult to visually confirm the positions and postures of the concave portion and the leg portions on both sides thereof, and it is also troublesome to check by groping. If the posture of the sealing ring is tilted or twisted, not only mounting becomes difficult, but also the sealing function during use is reduced. It is very difficult to insert the sealing ring into the dovetail groove in the correct posture over the entire circumference of the annular sealing ring.
It is conceivable that the concave portion of the heart-shaped sealing ring is formed deeply so that the left and right leg-shaped portions can be easily narrowed inward, and can easily pass through the opening. However, when the concave portion is deepened, when a load is applied during use, excessive stress concentration occurs at the bottom of the concave portion, and the durability of the sealing ring decreases. Fine cracks are generated on the surface of the concave portion due to excessive stress concentration, and fine spalls, that is, particles are generated by repeated load. It is difficult to use in applications where fine foreign matter is not to be mixed as in the semiconductor manufacturing apparatus described above. Further, in an environment in which a plasma gas or the like comes into contact with the sealing ring, there is a problem that the plasma gas acts on fine cracks to accelerate the deterioration of the sealing ring.

[0007] In the heart-shaped sealing ring, the left and right side walls are inclined or slightly curved outward.
The tapered inner wall of the dovetail groove having a trapezoidal cross section and the side wall of the heart-shaped sealing ring are arranged closest to the opening of the dovetail groove. Therefore, during or after the mounting operation, the side wall of the sealing ring rubs against the opening edge and is easily scratched or scraped off. Further, if a load is applied during use and the sealing ring is deformed so as to expand left and right, the side wall of the sealing ring comes into contact with the opening edge, and the above-described problem is more likely to occur. When the side wall of the sealing ring is rubbed by the opening edge, particles are generated, and the durability of the sealing ring also decreases. The side wall of the sealing ring may be damaged by being pinched between the opening edge and the mating flange, or the sealing function may not be sufficiently exerted.

An object of the present invention is to solve the above-mentioned problems of the prior art and to provide a sealing ring which can be easily mounted in a dovetail groove and has an excellent sealing function.

[0009]

SUMMARY OF THE INVENTION A sealing ring according to the present invention is mounted on a dovetail groove provided on one of the members at a joint portion between the members, and seals the joint portion by contacting the other member. A sealing ring for stopping, which is made of an elastically deformable material, has an annular shape, and has a cross-sectional shape and protruding portions protruding in three directions on an outer periphery, and a concave portion disposed between each protruding portion. And [Joining location] Sealing rings are used in various types of machinery.
It is used at a place where a pair of members are joined face-to-face to increase the airtightness at the joined place. There is no particular limitation on the structure and shape of the members forming the joining portion as long as the structure is required to have such improved airtightness, that is, a sealing function.

[0010] As a joining place where high airtightness is required,
Examples include joints of various pipes in a semiconductor manufacturing apparatus, an outer structure of a processing space, and an opening / closing part. Examples include a thin film forming apparatus and a gas processing apparatus that handle various gases. The present invention can also be applied to a severe environment in which the material of the sealing ring such as plasma gas is likely to deteriorate. A specific example is a gate valve opening / closing part of a dry etching chamber in a dry etching apparatus. In either case, a pair of members face each other at the joint, and one of the members is provided with a dovetail groove, and a sealing ring is mounted in the dovetail groove. The other member may be a simple flat surface, or a shallow groove or a step may be provided at a location corresponding to the dovetail groove.

[Dove groove] The basic sectional structure of the dove groove is that the width on the inner side is wider than the opening. The bottom surface of the dovetail can be a flat surface parallel to the opening. Both side surfaces of the dovetail groove may be inclined surfaces that are inclined inward from the bottom side to the opening side. The inclination angles may be different on both sides. The side surface may be a curved surface. The corner where the side surface and the bottom surface intersect, and the inner edge of the opening can be rounded or chamfered.

[0012] The dovetail groove is arranged in an annular shape surrounding the area to be sealed at the above-mentioned joint. For example, it is arranged in an annular shape surrounding the outer periphery of the fluid passage. The arrangement shape of the dovetail groove can be appropriately set according to the shape of the sealing cross section, such as an ellipse, an oval, a rectangle, a polygon, etc., in addition to a circle. [Sealing Ring] For the material and the basic structure of the sealing ring, the same technology as that of a normal O-ring and other sealing rings can be adopted. As the material of the sealing ring, a natural or synthetic rubber material or elastic resin material can be used as long as the material is capable of elastic deformation required for the sealing function. Specifically, an appropriate material can be selected according to the conditions of the environment to be sealed (conditions such as the type of fluid, temperature, and pressure). For example, in the field of semiconductors, a fluorine-based rubber (F) having a certain degree of resistance to plasma frequently used in dry etching.
KM) is suitable, and in particular, perfluoroelastomer (FFKM) is a preferred material.

The basic structure of a sealing ring is an annular body or ring having a specific cross-sectional shape. The ring diameter of the sealing ring and the arrangement shape of the ring are set in accordance with the ring diameter and arrangement shape of the dovetail groove to be mounted. The cross-sectional shape of the sealing ring is 3
Directional projections and recesses are provided. Such a shape may be referred to as a trifurcated shape or a trifurcated shape. The protrusion is disposed so as to protrude outward on the outer periphery of the sealing ring,
A portion that is recessed in the middle of the adjacent protruding portion compared to the protruding portion is a recessed portion. The tip of the protruding portion preferably has a smooth curved shape such as an arc shape. If the shape is smooth, it is difficult for the inner edge of the dovetail groove to be caught or damaged. The generation of fine fragments and powder during use is also reduced. The occurrence of excessive stress concentration can also be prevented.

It is preferable that the recessed portion has a curved shape such as an arc shape smoothly connected to the projecting portions on both sides. If it is smoothly connected to the protruding part, it is difficult for the recess to come into contact with the inner edge of the opening when the sealing ring is inserted into the dovetail groove. The Sooms can enter the inside of the dovetail groove into the part. The protrusions and recesses in the three directions may all have the same size and shape, or may have different sizes and shapes in combination. For example, if the protruding portions and the recessed portions in the three directions are arranged at equal intervals with the same dimensions and shapes, the cross-sectional shape will have a triangular shape with a substantially equilateral triangular overall shape. In this case, when the seal ring is mounted in the dovetail groove, the same mountability and sealing function can be exhibited even if the orientation of the sealing ring is in any direction, and handling becomes easy.

If the height of the one-way protrusion disposed on the opening side of the dovetail groove is made larger than that of the two-direction protrusion portion disposed on the bottom side of the dovetail groove, the protrusion on the opening side can be obtained. The portion is more likely to come into contact with the mating member at the joint, and the sealing function can be enhanced by increasing the amount of elastic deformation. When attached to the dovetail groove, two-sided protrusions located on the bottom side of the dovetail groove
With the same size and shape, the sealing ring can be stably arranged in the dovetail groove. If the sealing ring is symmetrical with respect to the vertical center line of the sealing ring in the mounting posture, stable mounting is possible, and it is possible to uniformly deform the left and right when a load is applied, so that the sealing function is less likely to be biased.

When it is necessary to make a difference in the sealing function between the left and right sides of the sealing ring due to a difference in pressure applied from the left and right sides of the dovetail groove or the like, an asymmetrical cross-sectional shape can be adopted. The protrusions and recesses in the three directions may all have different dimensions and shapes. [Dimensions of Dovetail Groove and Sealing Ring] The performance of the sealing ring can be improved by appropriately setting the dimensions of each part of the dovetail groove and the sealing ring. As the size and shape of the dovetail groove, conditions specified by standards such as JIS-B2401 and AS568A are adopted. The size of the sealing ring is set according to the size and shape of the dovetail groove determined in this way.

For example, for an opening width g of the dovetail groove of 1.71 mm, a height H in the mounting posture of the sealing ring is 1.89 m.
m ± 0.1 mm, and the width W in the mounting posture is set to 2 ± 0.1 mm. For an opening width g of the dovetail groove of 9.24 mm,
Height H in the mounting position of the sealing ring = 10 mm ± 0.3 m
m, the width W in the mounting posture is set to 11 ± 0.3 mm, and the like. Further, the dimensions of the dovetail groove and the sealing ring can be set in the following relationship. At least one of the bidirectional protrusions arranged on the bottom side of the dovetail groove when mounted in the dovetail groove
Is X / g = 1.2 to 1 with respect to the opening width g of the dovetail groove from the tip of the projecting portion in one direction to the bottom of the concave portion arranged between the projecting portions in the other two directions. .0. Preferably, X / g is 1.05 to 1.10.

If X / g is too large, a large force is required to insert the sealing ring into the dovetail groove, making the operation difficult. As a result, the sealing ring is easily damaged during insertion.
If X / g is too small, the sealing ring tends to come off from the dovetail after insertion, and the sealing function also deteriorates. The depth D of the recessed portion arranged on the bottom side of the dovetail when mounted in the dovetail is D / H = 0.15-0.
05. If D / H is too large, excessive stress concentration occurs on the central surface of the recess due to the load during use. As a result, fine cracks are generated in the sealing ring, and fine flakes and abrasion powder, that is, particles are easily generated. If D / H is too small, the concave portion will come into contact with the bottom surface of the dovetail groove when a slight load is applied during use. Effectively works in the stage until a sufficiently large tightening load is applied to the sealing part and in sealing under a low tightening load. Will be less effective. The sealing function under a low tightening load is reduced. At the time of mounting, the sealing ring is not stably arranged on the bottom surface of the dovetail groove, and the sealing ring easily rolls or tilts in the dovetail groove.

The tip of the protrusion has an arc shape, and the radius R of the arc is R / g = 0.4 with respect to the opening width g of the dovetail groove.
０．２0.2. Preferably, R / g =
0.35 to 0.25. If R / g is too large, the protruding portion becomes large, so that insertion into the dovetail groove becomes difficult. It becomes difficult to arrange a sufficiently large concave portion. If R / g is too small, excessive stress is generated at the tip of the protruding portion during use. As a result, the protruding portion is likely to bend and the sealing failure is likely to occur. [Installation of Sealing Ring] An annular sealing ring is sequentially inserted along an annular dovetail groove. However, since the entire width of the sealing ring in the mounting posture is larger than the opening width of the dovetail groove, it is difficult to insert the sealing ring into the dovetail groove in the mounting posture.

Therefore, one of the two projections on the bottom side of the sealing ring is inserted into the dovetail first.
The sealing ring will be slightly tilted. A concave portion adjacent to the upper side of the protrusion inserted into the dovetail groove is engaged with the opening edge of the dovetail groove, and the protrusion at a position facing the concave portion contacts the upper portion of the opening edge on the opposite side. Push the protruding part in contact with the upper part of the opening edge downward, and push the entire sealing ring into the interior of the dovetail groove by turning the entire sealing ring from the recessed part locked at the opening edge of the dovetail groove. Then, the protruding portion in contact with the upper part of the opening edge is elastically deformed, and the whole sealing ring is smoothly inserted into the dovetail groove with a relatively small force. Since there is no need to force the sealing ring into the opening edge of the dovetail groove and push it in, the generation of particles and damage to the sealing ring during mounting work can be prevented, and work efficiency is improved.

The sealing ring inserted into the dovetail groove is arranged in a stable posture, with the left and right protruding portions on the bottom side surely abutting against the bottom surface of the dovetail groove. The sealing ring is prevented from being twisted or tilted. The remaining one-way protruding portion is disposed so as to protrude above the opening of the dovetail groove. Since the recessed portions arranged on the left and right of the protruding portion are arranged near the opening of the dovetail groove, there is sufficient room between the opening edge of the dovetail groove and the sealing ring, and the sealing ring is Rubbing and damage are prevented. Conventionally, in the case of an O-ring that has been generally used as a sealing ring, twisting easily occurs when the O-ring is attached to a dovetail groove. Moreover, it is difficult to confirm whether or not the O-ring having a circular cross section is twisted. In the case of the sealing ring of the present invention, the structure is such that the twist is unlikely to occur as described above, and if the twist occurs, the length of the protrusion formed on the upper side is inclined or formed by the protrusion and the recess. Since the stripe pattern extending in the direction is displaced or twisted, occurrence of the twist can be surely found by visual observation. If the twist can be confirmed, the sealing ring can be twisted in the opposite direction inside the dovetail groove to eliminate the twist. The operation of returning the twist can be relatively easily performed by moving the projecting portion projecting upward to the left and right.

[Sealing Function of Sealing Ring] A member on the mating side is arranged above the dovetail groove on which the sealing ring is mounted, and the members are joined to each other, so that the sealing ring is placed on the surface of the mating member. To seal the joint. At the joint between the members, the tip of the projecting portion of the sealing ring mounted on the dovetail groove projects above the dovetail groove abuts the surface of the mating member. When the tip of the protruding portion is elastically deformed, a sufficient surface pressure is generated between the protruding portion and the surface of the mating member to perform a sealing function.

Even if the recesses disposed on the left and right sides of the protrusion are deformed so as to expand outward due to the elastic deformation of the protrusion, there is a sufficient margin between the opening edge of the dovetail groove and the recess. Accordingly, the sealing ring is prevented from being sandwiched between the opening edge and the counterpart member, and the sealing ring is prevented from being damaged by the surface of the sealing ring being hooked on the opening edge. External force applied to the sealing ring from above is supported on the bottom surface of the dovetail through two-way protrusions disposed on the bottom surface side of the dovetail. The protrusions in the two directions are elastically deformed and pressed against the bottom of the dovetail groove. The compressive stress transmitted downward from the upper protrusion is
Acts to push the left and right protrusions apart, ensuring the elastic repulsion required for sealing. In the case where it is only necessary to seal with a relatively low tightening load, the necessary sealing function can be exhibited by the elastic repulsive force accompanying the deformation of the projecting portion in the two directions.

In the case of sealing by applying a large tightening load, it can be deformed until the concave portion on the bottom side disappears in the middle of the tightening and the protruding portions in the two directions are connected. When the bottom recessed portion has substantially disappeared, the expansion in which the left and right protruding portions are expanded does not progress even if a further compressive stress is applied. When the surface of the protruding part is strongly rubbed against the inner surface of the dovetail with the expansion, a part of the protruding part is peeled off, so-called particles are generated.
If the enlargement does not proceed, the generation of such particles can be suppressed. The sealing ring of the present invention can be easily inserted into the dovetail groove even if the bottom recess is shallower than the heart-shaped sealing ring of the prior art described above.

If the bottom recess is made shallow, even when the above-mentioned large tightening load is applied, the protrusion on the bottom is unnecessarily deformed and particles are generated due to friction with the dovetail bottom. Is less likely to occur. Furthermore, since excessive stress concentration does not occur in the bottom recessed portion, cracks due to the stress concentration are prevented, and a stable sealing function can be exhibited for a long time even in a plasma environment or the like. Such a function is particularly effective when used for sealing a valve or the like that is frequently opened and closed repeatedly.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiment shown in FIGS. 1 to 4 shows a sealing ring 10 made of an elastic resin and having a whole annular shape. [Structure of Sealing Ring] As shown in FIG. 1 (a), the cross-sectional shape of the sealing ring 10 is substantially triangular in shape of an equilateral triangle, and has the same dimensions and shape extending from the center to the outer periphery in three directions. Projections 12a, 12b, 12c and
... recesses 14a, 14 of the same size and shape arranged between
b, 14c. In the circumferential direction, protruding portions 12a in three directions and concave portions 14a in three directions are arranged at regular intervals of 120 °. It is symmetrical about the center of the sealing ring 10 every 120 °.

The tip side of each of the protruding portions 12a has an arc shape. Each of the concave portions 14a is also formed in an arc shape, and is smoothly connected to the projecting portions 12a on both sides. [Dimensions of each part of the sealing ring] FIG.
0 shows how to determine the dimensions of each part. Each projection 12a
Are represented by Ra, Rb, and Rc, respectively. Ra, Rb, and Rc all have the same value. Recess 14
The depth Db of b is the distance from the line connecting the vertices of the protrusions 12b and 12c on both sides to the bottom of the recess 14b. Although not shown, the depths Da and Dc of the recessed portions 14a and 14c are represented by the same reference.

The total height Ha is calculated from a line connecting the two protruding portions 12b and 12c arranged at the bottom, that is, from the bottom surface.
It is represented by the distance to the protruding portion 12a arranged at the top in the remaining one direction. When the protruding portion 12b or 12c is arranged on the upper portion, the overall heights Hb and Hc (not shown) in each case are represented by the same reference as Ha. Further, from the tip of the one-way projection 12c, the remaining two-direction projection 12
The distance Xc to the bottom of the middle recessed part 14a between the points a and 12b is defined. Similar distances Xb and Xa (not shown) are defined for the protruding portions 12b and 12a. Projecting portion 12b,
The total width Wbc of the sealing ring 10 when the sealing ring 12c is arranged on the bottom side is defined. The total width Wab, Wca (not shown) is determined by the combination of the protrusions 12a arranged on the bottom side.
Is also specified.

By appropriately setting the dimensions of these parts, the performance of the sealing ring 10 can be improved. [Sealing Ring Mounting Work] As shown in FIG. 2, a sealing ring 10 is provided on a joining surface of a joining member 20 such as an on-off valve of a valve or a flange of a pipe joint. Is mounted in the dovetail groove 22 formed in the groove. The structure of the dovetail groove 22 will be described with reference to FIG. The basic structure of the dovetail groove 22 has a trapezoidal cross section in which the inner width of the dovetail groove 22 is larger than the width g of the opening 24. Bottom 26
Is flat, and the left and right side surfaces 28, 28 are inclined inward from the bottom surface 26 side toward the opening 24 side. Therefore, the inner width increases toward the bottom surface 26. The edge of the opening 24 is rounded. A corner formed by the bottom surface 26 and the inclined side surface 28 is also rounded.

The sealing ring 10 is mounted and used in the dovetail groove 22 having the above structure. As described above, since the dovetail groove 22 is arranged in a circular or rectangular ring shape on the surface of the joining member 20, the sealing ring 10 is also attached to the dovetail groove 2.
It is formed in an annular shape having substantially the same length as the annular circumferential length of No. 2. As is apparent from FIG. 3, the total width Wbc of the sealing ring 10 in the mounted state is larger than the width g of the opening 24 of the dovetail groove 22.
The height Ha of the sealing ring 10 is higher than the height h of the dovetail groove 22. If the sealing ring 10 is to be inserted into the dovetail groove 22 from the outside of the joining member 20 while keeping the posture at the time of attachment, the entire width Wbc of the sealing ring 10 becomes smaller than the opening width g of the dovetail groove 22. It is necessary to be elastically deformed. However, this requires a great deal of force and is time-consuming.

On the other hand, according to the method shown in FIG. 2, the operation of inserting the sealing ring 10 can be easily performed. 2 of the sealing rings 10 arranged on the bottom side in the mounted state
One of the protrusions 12b and 12c
Only b is inserted into the opening 24 of the dovetail groove 22. The sealing ring 10 may be slightly inclined. Protruding part 1 in one direction
If it is only 2b, it is inserted into the opening 24 of the dovetail groove 22 without resistance. The recess 14 a of the sealing ring 10 is arranged on the inner edge of the opening 24, and the projection 12 c contacts the upper side of the opening 24. The distance Xc from the protrusion 12c to the recess 14a is:
The sealing ring 10 is narrower than the entire width Wbc of the sealing ring 10 but slightly larger than the width g of the opening 24, so that the sealing ring 10 comes into contact with the upper surface of the opening 24.

When the projecting portion 12c is pressed from above and the sealing ring 10 is elastically deformed and pushed into the opening 24, the sealing ring 10 is stepped as shown by a two-dot chain line in FIG. While elastically deforming, it moves so as to pivot around the position of the recessed portion 14 a abutting on the inner edge of the opening 24, and the entirety of the sealing ring 10 is
2 is inserted inside. At this time, the projecting portion 12c at a position facing the recessed portion 14a and its peripheral portion mainly deform elastically. Since the distance Xc from the protrusion 12c to the recess 14a does not greatly differ from the opening width g, the amount of elastic deformation described above does not need to be so large. Further, by pushing in such a manner that the sealing ring 10 is swung starting from the recessed portion 14 a locked to the inner edge of the opening 22, the pushing force efficiently deforms the sealing ring 10 elastically and pushes the sealing ring 10 downward. Act on. As a result, the operation of inserting the sealing ring 10 into the dovetail groove 22 can be performed extremely smoothly with a small force. If the sealing ring 10 is arranged above the dovetail groove 22 with the sealing ring 10 slightly inclined, the recess 14 a
Is naturally positioned at the inner edge of the opening 24, so that the posture and position of the sealing ring 10 do not need to be strictly adjusted, and the sealing ring 10 can be easily and quickly inserted without knowing special skills and tips. Work can be done.

[Sealing Function of Sealing Ring] After the insertion operation shown in FIG. 2, the sealing ring 10 is mounted in the dovetail groove 22 in the state shown in FIG. On the bottom surface 26 of the dovetail groove 22,
The two-direction protrusions 12b and 12c of the sealing ring 10 abut, and a part of the one-way protrusion 12a is
It will be in a state of projecting upward. Left and right protrusions 12
Since b and 12c are supported by the bottom surface 26 of the dovetail groove 22, the posture of the sealing ring 10 is stable. Further, since the substantially triangular outer shape of the sealing ring 10 is arranged along the taper of the side surface 28 of the dovetail groove 22, the sealing ring 10 excessively moves inside the dovetail groove 22 to roll or twist. I will not do it.

However, since the entire width Wbc of the sealing ring 10 is slightly smaller than the inner width of the dovetail groove 22, the sealing ring 10 may move left and right or deform within a certain range inside the dovetail groove 22. Is possible. As shown in FIG. 4, another joining member 30 is brought into contact with the joining member 20 provided with the dovetail groove 22 to close the joining portion. The surface of the mating joining member 30 comes into contact with the protruding portion 12a of the sealing ring 10 protruding above the dovetail groove 22, and is elastically deformed so as to compress the protruding portion 12a downward. The protruding portion 12a is deformed so as to be pushed and contracted downward and to expand right and left.
The force applied to the protrusion 12a causes the protrusion 12
b and 12c are also elastically deformed. Projections 12b, 12c
Is deformed so as to be compressed vertically and spread left and right. The protrusions 12b and 12c are on the side surface 2 of the dovetail groove 22.
Until abutting on 8, the projections 12b, 12c can expand freely. The concave portion 14b on the bottom side is deformed so that the depth Db becomes smaller. The deformation may be made to such an extent that the recess 14b is substantially eliminated. If the recessed portion 14b is eliminated, the protruding portions 12b and 12c will not spread left and right beyond that.

As a result, a large pressure is generated on the contact surface between the projecting portion 12a and the mating joining member 30, and a strong sealing function is exhibited. Projections 12b in two directions on the bottom side, 1
When the 2c is pressed against the bottom surface 26 of the dovetail groove 22, a sufficient contact force is generated between the two and the sealing function is exhibited. The repulsive force generated by the pressure contact between the protrusions 12b and 12c and the bottom surface 26 of the dovetail groove 22 increases the pressure contact force between the upper protrusion 12a and the mating joining member 30. Since the top-side projection 12a is arranged vertically above the center of the bottom-side projections 12b and 12c which are arranged left and right with the recessed portion 14b interposed therebetween, the left and right projections 12b and 12c are arranged.
b, 12c and the bottom surface 26 of the dovetail groove 22 ensure that the top-side protruding portion 12a securely engages the mating joining member 3
It acts in the direction of pressing against 0, and can exert a stronger sealing function.

The protrusion 12b on the bottom side of the sealing ring 10
12c and the bottom surface 26 of the dovetail groove 22, the protrusion 12
b, 12c are deformed so as to expand to the left and right, and the concave portion 14b
, The contact area between the sealing ring 10 and the bottom surface 26 of the dovetail groove 22 increases, and the contact stress generated in the sealing ring 10 decreases. In addition, the concave portion 1
4b is substantially eliminated, the protruding portions 12b and 12c do not spread left and right even if a larger load is applied, and the protruding portions 12b and 12c
2 are strongly rubbed against the bottom surface 26 of the projections 12b, 12
The problem that the surface of c is peeled off and particles are generated can be prevented.

As a result, even when the opening and closing operations of the joining members 20 and 30 are repeated,
It is less likely that the sealing ring 10 will be damaged or particles will be generated due to the friction with the sealing ring 10.

[0038]

[Dovetail to attach]

Opening width g = 3.34 mm Depth h = 2.51 mm Maximum inner width (bottom) = 4.45 mm Side inclination angle = 24 ° [Evaluation of sealing ring] Sealing ring 1 having the dimensions and shape described above.
No. 0 was mounted in the dovetail groove 22 having the above-mentioned dimensions and shape, and the mountability and the sealing function were measured and evaluated.

<Attachability> The force required for the attaching operation was compared with that of the above-mentioned sealing ring having a heart-shaped cross section. A heart-shaped sealing ring (comparative example) is disclosed in Japanese Unexamined Patent Application Publication No. 10-318373.
A heart-shaped sealing ring having a structure described in Japanese Patent Application Laid-Open No. H10-209,837 was used. The dimensions were 4.1 mm in width, 3.4 mm in height, and 4.1 mm in radius at the top. The load value required for pushing into the dovetail groove at the time of mounting was measured. As a result, it was proved that the sealing ring of the example can be attached to the dovetail groove with a much smaller force than the comparative example.

<Durability> The durability of the sealing ring when the joining and releasing operations of the members were repeated was evaluated. Further, in the sealing ring of the example, a difference in performance due to the depth Db of the bottom-side concave portion was verified. As an evaluation test, an operation of pressing the sealing ring at a surface pressure of 2 kgf / cm ² for 1 second was repeated 100,000 times. Thereafter, a sample was taken from the surface of the concave portion on the bottom side of the sealing ring and observed with a microscope. <Table 2. Recess depth and durability> Recess depth Observation result Db / Ha ──────────────────────── Example (trident) 0.1 No change 0.15 No change 0.2 No change 0.3 Slightly Micro crack generation ───────────────────────────── Comparative example (heart shape) 0.2 Micro crack generation ────── 、 As a result, in applications where repetitive force is applied, the structure of the example is much more durable than the structure of the comparative example. It was demonstrated that the property was excellent.

Even in the structure of the comparative example, if the depth of the concave portion is reduced, the occurrence of minute cracks may be eliminated. In this case, however, a larger force is required for the work of mounting the dovetail groove. In practice, it becomes impossible to mount the camera. Further, in the examples, it was found that when the depth of the recessed portion was too large, the durability was reduced. [Isosceles Triangular Seal Ring] The embodiment shown in FIG. 5 is different from the above embodiment in the cross-sectional structure of the seal ring. 1
Direction protruding part 12a, other two direction protruding parts 12b, 1
It extends to the outer peripheral side and is higher than 2c. As a result, the overall shape of the sealing ring 10 has an isosceles triangle.

When such a sealing ring 10 is used, the upper projecting portion 12 a protrudes above the dovetail groove 22 with the sealing ring 10 mounted in the dovetail groove 22. When the joining members 30 are overlapped and joined, the protruding portion 12a is largely compressed and deformed, so that a strong sealing force can be generated on the joining surface. If the dovetail groove 22 has a greater depth than the inner width, the height Ha is increased without increasing the width Wbc of the sealing ring 10 to secure a sufficient amount of protrusion in the upper part of the dovetail groove 22. can do. However, in the case of the sealing ring 10 of the above embodiment, the projection 12 a
It is necessary to carry out the mounting work in consideration of the posture so that the camera faces upward.

[0043]

The sealing ring according to the present invention is provided with the above-described three-direction projecting portion and concave portion,
The mounting work in the dovetail groove can be performed easily and reliably, and the sealing function at the time of use is extremely excellent. The generation of fine cracks and particles during mounting and use is reduced, and the durability of the sealing ring can be significantly improved. As a result, it can be practically used in applications that are difficult to use with conventional O-rings or heart-shaped sealing rings, such as in semiconductor manufacturing equipment that requires a high sealing function or in environments where the sealing ring is easily degraded. Sufficient performance can be exhibited, and it can also contribute to expansion of use and demand of the sealing ring.

[Brief description of the drawings]

FIG. 1 is a sectional view and a dimension designation diagram of a sealing ring showing an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a mounting operation of a sealing ring.

FIG. 3 is a sectional view showing a mounted state.

FIG. 4 is a sectional view showing a use state.

FIG. 5 is a cross-sectional view illustrating another embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Sealing ring 12a, 12b, 12c Projecting part 14a, 14b, 14c Depressed part 20 Joining member 22 Dovetail 24 Opening 26 Bottom surface 28 Side surface

Continued on the front page (72) Inventor Takashi Yamashita F-term (reference) 3J040 AA17 BA01 EA01 EA16 FA05 HA03 in Nippon Valqua Industry Co., Ltd.

Claims (6)

[Claims] 1. A sealing ring which is attached to a dovetail groove provided on one of the members at a joint portion between members and abuts on the other member to seal the joint portion, and is elastically deformable. A sealing ring, which is made of a material, has a ring shape, and has a projection portion projecting in three directions on an outer periphery in a cross-sectional shape, and a recessed portion arranged between the projection portions. 2. A distance between a tip of at least one of the two-direction protrusions disposed on the bottom side of the dovetail when mounted in the dovetail and another two-direction protrusion. The distance X to the bottom of the recessed portion arranged in the groove is the opening width g of the dovetail groove.
The sealing ring according to claim 1, wherein X / g is 1.2 to 1.0. 3. The depth D of the recessed portion disposed on the bottom side of the dovetail when mounted in the dovetail is equal to the height H of the entire sealing ring.
D / H = 0.15 to 0.05 with respect to
Or the sealing ring according to 2. 4. The tip of the projection has an arc shape, and the radius of the arc is R / g = R / g = the opening width g of the dovetail groove.
The sealing ring according to claim 1, wherein the number is 0.4 to 0.2. 5. The sealing ring according to claim 1, wherein said projecting portion and said recessed portion in said three directions have the same dimensions and shapes and are arranged at equal intervals in a circumferential direction. 6. A height of a one-way protrusion disposed on the opening side of the dovetail, as compared with a two-way protrusion disposed on the bottom side of the dovetail among the three-way protrusions. The sealing ring according to claim 1, wherein the sealing ring is large.