JP2005207526A - Flange seal structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flange seal structure allowing repetitive use easily many times and capable of serving in a high temperature environment. <P>SOLUTION: The flange seal structure 10 includes two flanges, among which one of them 11 provided with a ring-shaped projection to be fitted in a ring-shaped recess is fastened to the other 12 where the ring-shaped recess is formed through a ring gasket 13 having a V-section, wherein the ring-shaped recess assumes a V-groove 21 furnished at the opening end with a rounded portion 23 with the opening angle enlarging gradually while the ring-shaped projection assumes a V-projection 17 whose opening angle β is larger than the opening angle α of the V-groove 21 excluding the rounded portion 23, and the opening angle α of the V-groove 21 lies within the range between 20-50 degrees, while the opening angle β of the V-projection 17 is 2-10 degrees. greater than the opening angle of the V-groove 21. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

The present invention relates to a flange seal structure applied to, for example, a vacuum seal of a vacuum device, and more particularly to a flange that can withstand many uses and can be used in a high temperature environment, and a gasket used therefor. .

At present, the most popular flange seal structure in the ultra-high vacuum apparatus is, for example, a knife edge type metal seal flange structure (also called a conflat flange structure) 79.
For example, as shown in FIG. 5, the knife edge type metal seal flange structure 79 is formed with knife edges 82 and 83 each having a ring-shaped acute protrusion on the opposing surfaces of the flanges 80 and 81. 83, for example, an annular metal gasket 84 using oxygen-free copper defined by JIS-C1020 or JIS-C1011 is mounted as a sealing material. Further, for the positioning of the metal gasket 84, jetty jets 85 and 86 are provided inside the knife edges 82 and 83 of the flanges 80 and 81, respectively.
With this configuration, the knife edges 82 and 83 bite into the metal gasket 84 as shown in FIG. 5 in the process of fastening the flange 80 and the flange 81 using, for example, bolts (in the direction of arrow A). ). In this way, the metal gasket 84 is brought into contact with the flanges 80 and 81 at the biting portions of the knife edges 82 and 83 to form a seal portion, and the flange side and the metal gasket 84 side are connected with high pressure at the seal portion. Since they are in contact with each other, a highly reliable vacuum seal is achieved (for example, see Non-Patent Documents 1 and 2).

However, in the knife edge type metal seal flange structure 79 described in Patent Documents 1 and 2, the metal gasket 84 after use is formed with the biting grooves of the knife edges 82 and 83, and thus cannot be reused. .
For this reason, a type of flange seal mechanism is proposed in which the opposing surfaces of the flange are plated, and an oxygen-free copper metal O-ring is interposed between the flanges and fastened with bolts. Has been. However, a high pressure is generated at the contact portion between the metal O-ring and each flange at the time of fastening, and the metal O-ring is pressed against the plated flange surface, so when removing the metal O-ring after use The problem of peeling the plated portion from the flange side is likely to occur. For this reason, even in this type of flange seal structure, it is difficult to repeatedly use it many times.

Therefore, as shown in FIG. 6, a convex portion 88 having a ring-shaped cross-sectional outer shape is formed on the facing surface side of one flange 87 of the facing flanges 87 and 89, and the facing surface of the other flange 89 is formed. The ring-shaped cross-sectional outer shape into which the ring-shaped convex part 88 enters is formed in a concave shape 90, and between the convex part 88 and the concave part 90, for example, the cross-sectional external shape using oxygen-free copper is a square shape. A flange seal structure 92 of the type in which the annular metal gasket 91 is attached as a sealing material is considered.
Here, the convex portion 88 can easily enter the concave portion 90 so that a part of the side surface of the convex portion 88 and a part of the side surface of the concave portion 90 can be brought into close contact with each other with high pressure via the metal gasket 91. The angle θ formed by intersecting the two side surfaces P and Q when the 88 is viewed in cross section is smaller than the angle φ formed when the two side surfaces R and S when the recess 90 is viewed in cross section. . For this reason, the seal part formed in close contact with a part of the side surface of the convex part 88 and a part of the side surface of the concave part 90 is located on the bottom side of the concave part 90 (the top side of the convex part 88).

Satoshi Kurokawauchi and 4 others, “Consideration of Conflat Seal Mechanism Based on Gasket Deformation Behavior Observation”, Vacuum, Japan Vacuum Association, October 20, 1999, Vol. 42, No. 10, p. 910-917 Satoshi Kurokawauchi and two others, “Consideration of Conflat Seal Mechanism Based on Stress Analysis in Gasket”, Vacuum, Japan Vacuum Association, October 20, 1999, Vol. 42, No. 10, p. 918-922

However, in the flange seal structure 92 shown in FIG. 6, since the seal portion is located on the bottom side of the recess 90, when the flanges 87 and 89 are unfastened after use and the flanges 87 and 89 are separated from each other, The gasket 91 is left on the bottom side of the recess 90. For this reason, the problem that the metal gasket 91 after use becomes difficult to take out arises. Moreover, when taking out, a metal gasket may be deformed and it may become impossible to reuse.
Furthermore, when viewed from the convex portion 88, the seal portion exists on the top side of the convex portion 88. Therefore, when fastening is repeated by applying a large force to the flanges 87 and 89, the top side of the convex portion 88 is gradually deformed. As a result, there arises a problem that the sealing performance deteriorates. In particular, when it is necessary to retighten the flanges 87 and 89 to improve the fastening force as in use in a high temperature environment, the top side of the convex portion 88 is significantly deformed and stable in a high temperature environment. When used, there is a problem in reliability.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a flange seal structure that can be used repeatedly many times and can be used in a high-temperature environment.

The flange seal structure according to claim 1, wherein the flange seal structure according to claim 1 has a V-shaped cross section in which one flange having a ring-shaped recess is formed and the other flange having a ring-shaped protrusion to be fitted into the ring-shaped recess is formed. In the flange seal structure that is fastened through the ring gasket of
The ring-shaped concave portion is a V-shaped groove in which a rounded portion with an gradually increasing opening angle is formed at an opening end, and the ring-shaped convex portion has the V-shaped groove whose opening angle excludes the rounded portion. It is a V-shaped projection larger than the opening angle.

Since the opening angle (opening angle) of the V-shaped projection is larger than the opening angle of the V-shaped groove excluding the rounded portion, the side surface of the V-shaped projection hits the opening end of the V-shaped groove, that is, the rounded portion via the ring gasket. Therefore, the seal portion can be formed at the opening end portion of the V-shaped groove (a position away from the front end side of the V-shaped projection when the V-shaped projection is fitted into the V-shaped groove).
At this time, since the ring gasket has a V-shaped cross section, the ring gasket is arranged so as to cover the V-shaped protrusion, so that both side surfaces of the V-shaped protrusion respectively contact the rounded portions of the open end of the V-shaped groove through the ring gasket. Touch.

The flange seal structure according to claim 2 is the flange seal structure according to claim 1, wherein an opening angle of the V-shaped groove is in a range of 20 to 50 degrees, and an opening angle of the V-shaped protrusion is a width of the V-shaped groove. It is larger in the range of 2 to 10 degrees than the opening angle.
When the opening angle of the V-shaped groove is less than 20 degrees, the pressing force that pushes the ring gasket vertically decreases. On the other hand, when the opening angle of the V-shaped groove exceeds 50 degrees, the insertion depth of the V-shaped projection into the V-shaped groove is shortened, and positioning of the flanges becomes difficult. For this reason, the opening angle of the V-shaped groove was set to a range of 20 to 50 degrees.
When the difference between the opening angle of the V-shaped protrusion and the opening angle of the V-shaped groove is less than 2 degrees, the seal portion is formed on the back side of the opening end portion of the V-shaped groove (that is, the terminal end side of the rounded portion). When the difference between the opening angle of the protrusion and the opening angle of the V-shaped groove exceeds 10 degrees, the seal portion is formed on the opening side of the opening end portion of the V-shaped groove (that is, the starting end side of the rounded portion). Also in this case, the pressing force pushing the ring gasket vertically decreases. For this reason, the opening angle of the V-shaped projection is set in a range 2 to 10 degrees larger than the opening angle of the V-shaped groove.

The flange seal structure according to claim 3 is the flange seal structure according to claims 1 and 2, wherein the circles formed at the apexes of the opening angles of the V-shaped groove and the V-shaped protrusion are concentric and have the same radius.
By setting it as such a structure, both flanges can be aligned easily by inserting a part of V-shaped protrusion in a part of V-shaped groove.

In the flange seal structure according to any one of claims 1 to 3, since the ring-shaped convex portion is a V-shaped projection whose opening angle is larger than the opening angle of the V-shaped groove excluding the rounded portion, the side surface of the V-shaped projection is a ring gasket. The seal portion can be formed at the open end of the V-shaped groove by contacting the open end of the V-shaped groove, that is, the rounded portion, and the ring gasket can be removed when the opposing flanges are separated from each other. It can be left on the V-shaped projection side. As a result, the ring gasket can be easily removed without being deformed, and the ring gasket can be used many times. Since the rounded portion formed at the opening end of the V-shaped groove contacts the ring gasket, it is possible to prevent the bite at the opening edge of the V-shaped groove from being formed on the ring gasket. As a result, the gasket can be used many times.
Further, when the V-shaped projection is inserted into the V-shaped groove, the seal portion can be formed at a position away from the tip side of the V-shaped projection, that is, at the thick portion of the V-shaped projection. Even if it is inserted into the V-shaped groove and tightened by applying a large force, the deformation of the V-shaped projection can be suppressed, and it is possible to prevent the sealing performance from deteriorating even when used many times. Since the deformation of the V-shaped protrusion is suppressed, it can be stably used even in a high temperature environment where the flange needs to be tightened.
Furthermore, since the ring gasket has a V-shaped cross section, it is arranged so as to cover the V-shaped projection, so that both side surfaces of the V-shaped projection abut against both rounded portions of the open end of the V-shaped groove via the ring gasket. As a result, two inner and outer seal portions can be formed, and a highly reliable seal can be performed.

Particularly, in the flange seal structure according to claim 2, the opening angle of the V-shaped groove is in the range of 20 to 50 degrees, and the opening angle of the V-shaped protrusion is larger in the range of 2 to 10 degrees than the opening angle of the V-shaped groove. Therefore, it is possible to secure the pressing force to push the ring gasket vertically and to secure the depth of insertion of the V-shaped protrusion into the V-shaped groove, and to easily position the flanges by inserting the V-shaped protrusion into the V-shaped groove. It becomes possible to do. As a result, the flange can be easily attached. In addition, it is possible to secure a pressing force that vertically pushes the ring gasket existing between the V-shaped groove and the V-shaped projection, and it is possible to stably maintain the sealing performance.

In the flange seal structure according to claim 3, since the circle formed at the apex of the opening angle of the V-shaped groove and the V-shaped protrusion is concentric and has the same radius, a part of the V-shaped protrusion is part of the V-shaped groove. Positioning can be performed by fitting into the portion, and the entire V-shaped projection can be easily fitted into the V-shaped groove. As a result, the flange can be easily attached.

Next, embodiments of the present invention will be described with reference to the accompanying drawings for understanding of the present invention.
1A and 1B are a plan view and a side sectional view of the other flange of the flange seal structure according to the embodiment of the present invention, respectively, and FIGS. A plan view and a side sectional view of one flange of the flange seal structure, FIGS. 3A and 3B are a side sectional view of a ring gasket before and after pressing applied to the flange seal structure, and FIG. It is explanatory drawing which shows the state by which the V-shaped protrusion formed in the other flange was inserted in the V-shaped groove formed in one flange in the flange seal structure via the ring gasket.

As shown in FIGS. 1 to 4, a flange seal structure 10 according to an embodiment of the present invention includes another flange 11 attached to a vacuum device (not shown) and one flange 12 attached to the other flange 11. And a copper gasket 13 which is an example of a ring gasket having a V-shaped cross section provided therebetween. These will be described in detail below.
The other flange 11 has, for example, a disk shape made of stainless steel, and has a central portion with a back surface (vacuum device side) 14 to a front surface side (hereinafter, a surface facing the one flange 12). A circular opening 16 that is reduced in diameter in three steps toward the side 15 is provided. Further, a V-shaped projection 17 is formed on the facing surface side 15 as an annular ring-shaped convex portion concentric with the opening 16, and the apex of the opening angle of the V-shaped projection 17 is concentric with the opening 16. It exists on the circumference of one circle 18. Further, a plurality (eight in FIG. 2) of screw holes 19 are provided on the outer peripheral side of the flange 11.

The one flange 12 attached to face the other flange 11 is formed in a disk shape made of stainless steel having the same outer diameter as the other flange 11, for example, and faces the other flange 11. 20 is formed with a V-shaped groove 21 which is an annular ring-shaped recess concentric with one flange 12, and the apex of the opening angle of the V-shaped groove 21 is the circumference of the second circle 22 concentric with the flange 12. Exists on. The first circle 18 and the second circle 22 have the same radius.
Further, as shown in FIG. 4, a rounded portion 23 having a gradually increasing opening angle is formed at the opening end of the V-shaped groove 21, and the opening angle α of the V-shaped groove 21 excluding the rounded portion 23 is 20 The opening angle β of the V-shaped protrusion 17 is larger than the opening angle α of the V-shaped groove 21 by 2 to 10 degrees.
With this configuration, the side surface of the V-shaped protrusion 17 can be brought into contact with the open end of the V-shaped groove 21, that is, the rounded portion 23 via the copper gasket 13. The part can be formed. In addition, a pressing force that pushes the copper gasket 13 vertically is secured to stably maintain the sealing performance, and a depth of insertion of the V-shaped protrusion 17 into the V-shaped groove 21 is secured to position the flanges 11 and 12 together. Can be easily performed.

Further, on the outer peripheral side of the flange 12, through holes 24 through which bolts to be screwed into the screw holes 19 are inserted in the same number and the same pitch as the screw holes 19 are provided. By adopting such a configuration, the center of the flange 11 and the center of the flange 12 can be aligned by aligning the center of each screw hole 19 with the center of each through-hole 23.
As a result, the centers of the first circle 18 and the second circle 22 can be easily aligned, and the V-shaped protrusion formed on the other flange 11 is formed in the V-shaped groove 21 formed on one flange 12. 17 can be easily inserted.

The copper gasket 13 is obtained by punching an annular original ring gasket 13a from a copper plate having a thickness of about 0.1 to 0.5 mm and pressing it into a V-shaped cross section. The top portion 13b of the copper gasket 13 (copper gasket) The radius of the circle in which the apex of the V-shaped opening angle 13) exists on the circumference is the same radius as the first circle 18 in which the apex of the V-shaped protrusion 17 exists.
Here, the length b of the bus bar of the copper gasket 13 is shorter than the length a of one piece of the V-shaped protrusion 17. As a result, when the flange 11 and the flange 12 are fastened, the copper gasket 13 comes into contact with the opposed surface side 15 of the flange 11, and the copper gasket 13 prevents the sealing force from being reduced due to deformation.
Further, when the center line of the flange 11 is in a horizontal state, the copper gasket 13 can be attached simply by covering the V-shaped protrusion 17 and can be easily positioned without being dropped. The both side surfaces of the V-shaped protrusion 17 can be brought into contact with the respective rounded portions 23 at the open end of the V-shaped groove 21 through the copper gasket 13 for sealing.

Next, the usage method of the flange seal structure 10 which concerns on one embodiment of this invention is demonstrated.
First, the facing surface 15 of the other flange 11 is in a clean state, and the V-shaped protrusion 17 is covered with a copper gasket 13 having a bus bar having a length b shorter than the length a of one piece of the V-shaped protrusion 17.
Next, the center of each through-hole 24 formed in one flange 12 with the opposed surface side 20 in a clean state is positioned so as to coincide with the center of each screw hole 19 formed in the other flange 11. Adjustment is performed so that a bolt (not shown) is inserted into each through hole 24 and screwed into each screw hole 19 so that one flange 12 is maintained parallel to the other flange 11.

By screwing the bolts inserted into the respective through holes 24 into the respective screw holes 19, the one flange 12 gradually approaches the other flange 11 while keeping the center in alignment with each other. Here, since the centers of the one flange 12 and the other flange 11 are matched, the centers of the first circle 18 and the second circle 22 can be matched. Furthermore, since the first circle 18 having the apex of the opening angle of the V-shaped protrusion 17 and the second circle 22 having the apex of the opening angle of the V-shaped groove 21 have the same radius, When the first flange 12 approaches to some extent, the V-shaped projection 17 formed on the other flange 11 is inserted into the V-shaped groove 21 formed on one flange 12 via the copper gasket 13.
At this time, the copper gasket 13 covering the V-shaped protrusion 17 is gradually pushed into the V-shaped groove 21 as the V-shaped protrusion 17 moves.

As shown in FIG. 4, the opening angle α of the V-shaped groove 21 formed on one flange 12 is smaller than the opening angle β of the V-shaped protrusion 17 formed on the other flange 11. When 17 is inserted into the V-shaped groove 21 to some extent, the rounded portion 23 formed at the open end of the V-shaped groove 21 starts to contact the side surface of the V-shaped protrusion 17 via the copper gasket 13. For this reason, when one flange 12 is further brought closer to the other flange 11 while maintaining a parallel state, the copper gasket 13 placed on the V-shaped protrusion 17 is formed at the open end of the V-shaped groove 21. The rounded portion 23 is slid on the rounded portion 23 while being pushed toward the V-shaped protrusion 17 side and is pushed into the V-shaped groove 21.
When the rounded portions 23 formed at the open end of the V-shaped groove 21 are brought into contact with both side surfaces of the V-shaped projection 17 via the copper gasket 13, the V-shaped projection 17 is further moved into the V-shaped configuration. It cannot be fitted into the groove 21 and the attachment of one flange 12 to the other flange 11 is completed.

When the attachment of the one flange 12 to the other flange 11 is completed, the copper gasket 13 is in a state of covering the V-shaped protrusion 17. And since the big press has generate | occur | produced in the position where both the rounded parts 23 currently formed in the opening edge part of the V-shaped groove | channel 21 contact | abut on the both sides | surfaces of the V-shaped protrusion 17, the copper gasket 13 in the contact location. Are in close contact with the V-shaped protrusion 17 and the V-shaped groove 21 to form a seal portion. For this reason, a highly reliable seal is achieved in the seal portion.
Since the seal portion is formed at a position away from the tip end side of the V-shaped projection 17, that is, at the thick portion of the V-shaped projection 17, a large force is applied to bring the V-shaped projection 17 into the V-shaped groove 21. Even if it is inserted, the deformation of the V-shaped protrusion 17 can be suppressed, and it is possible to prevent the sealing performance from deteriorating even when used many times. Furthermore, since the deformation of the V-shaped protrusion 17 is suppressed, it is possible to use the flange 11 and 12 stably even in a high temperature environment where additional tightening of the flanges 11 and 12 is required.

Since the seal part is formed at a position corresponding to the rounded part 23 provided at the opening end of the V-shaped groove 21, the flanges 11, 12 are unfastened after use and the flanges 11, 12 are separated from each other. As a result, the copper gasket 13 remains on the V-shaped projection 17 side. For this reason, the copper gasket 13 can be easily removed, and the copper gasket 13 can be used many times.
When the copper gasket 13 is used repeatedly, the other flange 11 with the facing side 15 made clean is placed so that the V-shaped projection 17 is covered with the copper gasket 13 deformed in a V-shaped cross section. Then, one flange 12 having the opposed surface side 20 in a clean state is attached using a bolt.

As mentioned above, although embodiment of this invention was described, this invention is not limited to this embodiment, The change in the range which does not change the summary of invention is possible, Each above-mentioned embodiment is possible. The case where the vacuum sealing flange mechanism of the present invention is configured by combining some or all of the forms and modifications is also included in the scope of the right of the present invention.
For example, a copper gasket is used as the gasket, but a metal gasket formed of a metal that can be easily deformed, such as a copper alloy, aluminum, an aluminum alloy, or nickel, may be used.

(A), (B) is the top view and side sectional view of the other flange of the flange seal structure which concern on one embodiment of this invention, respectively. (A), (B) is the top view and side sectional drawing of one flange of the same flange seal structure, respectively. (A), (B) is a sectional side view of the ring gasket before and after press processing applied to the flange seal structure, respectively. It is explanatory drawing which shows the state in which the V-shaped protrusion formed in the other flange was inserted in the V-shaped groove formed in one flange in the same flange seal structure via the ring gasket. It is explanatory drawing of the flange mechanism for vacuum seals which concerns on a prior art example. It is explanatory drawing of the flange mechanism for vacuum seals which concerns on another prior art example.

Explanation of symbols

10: Flange seal structure, 11: The other flange, 12: One flange, 13: Copper gasket, 13a: Original ring gasket, 13b: Top part, 14: Back side, 15: Front side (opposite side), 16: Opening portion, 17: V-shaped projection, 18: first circle, 19: screw hole, 20: facing surface side, 21: V-shaped groove, 22: second circle, 23: rounded portion, 24: through-hole

Claims (3)

In a flange seal structure in which one flange formed with a ring-shaped recess is fastened with the other flange formed with a ring-shaped protrusion fitted into the ring-shaped recess via a ring gasket having a V-shaped cross section.
The ring-shaped concave portion is a V-shaped groove in which a rounded portion with an gradually increasing opening angle is formed at an opening end, and the ring-shaped convex portion has the V-shaped groove whose opening angle excludes the rounded portion. A flange seal structure characterized by being a V-shaped protrusion larger than the opening angle. 2. The flange seal structure according to claim 1, wherein an opening angle of the V-shaped groove is in a range of 20 to 50 degrees, and an opening angle of the V-shaped protrusion is in a range of 2 to 10 degrees from an opening angle of the V-shaped groove. A flange seal structure that is large. 3. The flange seal structure according to claim 1, wherein the circles formed at the apexes of the opening angles of the V-shaped grooves and the V-shaped projections are concentric and have the same radius. Flange seal structure.

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