JP2016183729A - Metal seal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a metal seal that endures high temperature and can be used as it is (in place of a conventional seal material) without machining a groove in flanges of a pipe connection part of a vacuum device or a semiconductor manufacturing device.SOLUTION: A metal seal comprises a U-shaped seal part 3 for sealing a gap between two planes 5 and 6 parallel to each other. Bulge parts 4 and 4 are formed by protruding a bottom wall part 3A of the U-shaped seal part 3 in both thickness directions, and outer peripheral surfaces 4A and 4A of the bulge parts 4 and 4 constitute a guide part G for centering.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a metal seal.

Various sealing materials are used in piping connection portions of semiconductor manufacturing equipment. For example, a seal member 36 in which two parts of a rubber O-ring 39 and a holding member 38 having a T-shaped cross section as shown in FIGS. That is, the two planes 40 </ b> A and 41 </ b> A corresponding to the flange portions 40 and 41 are sealed with the rubber O-ring 39. The holding member 38 has an arcuate recess 37 for holding the O-ring 39 (see FIG. 4 of Patent Document 1).
However, recently, in the semiconductor manufacturing apparatus, the atmospheric temperature (temperature of the fluid used) has been set high, and may reach, for example, 500 ° C. Under such severe temperatures, the sealing material 36 shown in FIGS. 6 and 7 cannot be used in terms of heat resistance because the O-ring 39 is made of rubber.
Therefore, as the sealing material that can withstand such a high temperature, the present inventor has also studied the application of a U-shaped metal seal 42 made entirely of metal as shown in FIG. 8 (FIG. 7 of Patent Document 2). reference).

JP-A-8-210572 JP 2013-155769 A

  However, in order to apply the metal seal 42 as shown in FIG. 8 to the place where the seal material 36 shown in FIG. 6 is used, there are the following problems.

That is, (i) if the U-shaped metal seal 42 as shown in FIG. 8 is interposed between the two planes 40A and 41A of the flange portions 40 and 41 shown in FIG. The axis L ₄₀ (of the hole) of the portions 40 and 41 does not match. That is, the centering function cannot be exhibited and the sealing performance cannot be obtained. (Ii) In order to provide such a centering function, as shown by a two-dot chain line in FIG. 8, a concave seal groove 43 is formed in one of the two parallel planes 40A and 41A by cutting or the like. It is necessary and modification of the flange portion 41 is required. (iii) The U-shaped metal seal 42 has a sealing action when the tip seal ridges (projections) 44 and 44 are pressed against the mating flat surface due to its strong resilience. In the pipe connection part 35 as shown in FIG. 6, the diameter and number of the tightening bolts, the wall thickness dimensions of the flange parts 40, 41, etc. are for the original rubber O-ring 39. Since it is designed and the pressing force of the two planes 40A and 41A is set to be small in advance, the pressing force of the two planes 40A and 41A against the U-shaped metal seal 42 cannot be increased too much. Therefore, the U-shaped metal seal 42 shown in FIG. 8 remains uneasy about the sealing performance (sealing performance).

  Therefore, the present invention solves the problems of the conventional sealing materials as described above, can sufficiently cope with the recent high ambient temperature, and furthermore, flanges of pipe connection portions of vacuum devices, semiconductor manufacturing devices, liquid crystal panel manufacturing devices, etc. An object of the present invention is to provide a metal seal excellent in sealing performance that can be used as it is (without replacing the conventional sealing material) without processing the seal groove.

  The metal seal according to the present invention includes a U-shaped seal portion that seals between two planes parallel to each other, and a locking bulging portion projects from a side surface near the base of the U-shaped seal portion, A centering guide is integrally formed.

In addition, a first seal protrusion is formed at the tip of the pair of elastic leg pieces of the U-shaped seal portion, and further, at the corner between the side surface near the base and the bulging portion of the U-shaped seal portion. In addition, a second seal protrusion smaller than the first seal protrusion is formed on each of the side surfaces closer to the base.
Further, a guide gradient surface is formed at the tip corner of the bulging portion.
Further, the second seal protrusion is formed in a triangular mountain shape or a trapezoidal mountain shape cross-sectional shape.

  According to the metal seal of the present invention, centering can be performed without processing the sealing groove into a concave shape in two parallel flat surfaces to be sealed, and replacement with a conventional sealing material can be easily performed. It can withstand use in high temperatures and can be applied to recent semiconductor manufacturing equipment.

It is sectional drawing of the free state which showed one Embodiment of this invention. It is a principal part expanded sectional view of FIG. It is sectional drawing which shows a compression use state. It is a principal part expanded sectional view of FIG. It is a principal part expanded sectional view explaining an effect | action. It is sectional drawing 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. It is sectional explanatory drawing which shows another prior art example.

Hereinafter, the present invention will be described in detail based on the illustrated embodiment.
The metal seal S of the present invention is used, for example, in a pipe connection part of a vacuum apparatus, a semiconductor manufacturing apparatus, a liquid crystal panel manufacturing apparatus, or the like. In the embodiment shown in FIG. 3, a U-shaped seal portion that is interposed between two parallel planes 5 and 6 of the joint 14 for piping and seals the inside 10 and the outside 11 of the joint 14 in a compressed use state. 3 is provided. In the cross section, as shown by a solid line and two-dot chain lines 18 and 18 in FIG. 1, the U-shaped seal portion 3 is separated from the bottom wall portion (base portion) 3A and the bottom wall portion 3A (toward radially outward). It has a pair of cantilever-like elastic leg pieces 7, 7 protruding in parallel. Then, the bulging portions 4 and 4 for locking protrude from the side surfaces 3E and 3E closer to the base of the U-shaped seal portion 3 to form a centering guide portion G.
The bulging portion 4 has a substantially rectangular cross section, and in the example shown in FIGS. 3 and 4, the metal seal having an annular shape as a whole has a groove 15 in the U-shaped seal portion 3. The centering guide portion G is configured by the outer circumferential surfaces 4A and 4A of the bulging portions 4 and 4 that are open in the radial outward direction and are annular in general. In addition, the bulging parts 4 and 4 can also be paraphrased when the bottom wall part 3A of the U-shaped seal part 3 is formed so as to protrude in both thickness directions.

As shown in FIG. 1, in the free state, the U-shaped seal portion 3 is provided on both side surfaces 7E, 7E, 3E, (except for the first seal protrusion 1 and the second seal protrusion 2 described later). 3E are parallel to each other and formed on the flat surfaces 16 and 16.
In the present invention, the material of the metal seal is preferably composed of a heat-resistant alloy, for example, a Ni-based alloy. In addition, in the pipe joint 14 illustrated in FIG. 3, the axially orthogonal end faces 12 </ b> A and 13 </ b> A of the flange portions 12 and 13 of the pair of metal couplings are sealed by the U-shaped seal portion 3. It corresponds to two parallel planes 5 and 6. For example, gas (gas) or liquid such as oxygen plasma or oxygen radical flows in the inside 10 of the piping joint 14, and the outside 11 is the atmosphere or other fluid. The atmosphere inside 10 of the pipe joint 14 is lower than the atmosphere outside 11.

As shown in FIG. 1, the front end portion 7 a of the elastic leg piece 7 is formed with a first seal protrusion 1 that contacts each of the two flat surfaces 5 and 6, and the side surface near the base portion of the U-shaped seal portion 3. At the corner R between 3E and the bulging portion 4, a second seal protrusion 2 is formed on each of the side surfaces 3E and 3E.
The second seal protrusion 2 is set to have a protrusion height dimension (and a cross-sectional area) smaller than that of the first seal protrusion 1, and in the free state, the second end portions 7a and 7a of the elastic leg pieces 7 and 7 are free. The width dimension W ₁ between the first seal protrusions 1 and ₁ is set to be larger than the width dimension W ₂ between the second seal protrusions 2 and 2. That is, when the U-shaped seal portion 3 is tightened by gradually bringing the two planes 5 and 6 closer together, the two planes 5 and 6 first come into contact with the first seal protrusions 1 and 1 of the tip portions 7a and 7a, and the elasticity The leg pieces 7 and 7 are elastically deformed, and then, as shown in FIG. 4, the two planes 5 and 6 abut against the second seal protrusions 2 and 2.
In the compression use state shown in FIG. 4, repulsive forces F and F are generated on the first seal protrusions 1 and 1 of the tip portions 7a and 7a, and the first seal protrusions 1 and 1 have two repulsive forces F and F in two planes. The two planes 5 and 6 are sealed (sealed) by being pressed against 5 and 6. In addition, although the 1st seal | sticker protrusion 1 is a cross-sectional shape of a small round mountain type in the example of a figure, it is good also as a triangular mountain type.

As shown in FIG. 1, in a free state, with respect to the width _{W 1} between a first sealing protrusion 1,1 mutually width _{W 2} between the second sealing protrusion 2,2 mutually example, 85% It is set to about ~ 95%.
If the width dimension W2 between the second seal protrusions 2 and ₂ is less than the lower limit value, the elasticity of the elastic leg pieces 7 and 7 when the two planes 5 and 6 come into contact with the second seal protrusions 2 and 2. Deformation becomes excessive.
When the width W ₂ between the second sealing protrusion 2,2 mutually exceeds the upper limit, insufficient elastic deformation of the cantilever elastic leg pieces 7, 7, the repulsive force F, may F is insufficient is there.

  As shown in FIG. 2, the second seal protrusion 2 is formed in a small triangular mountain cross-sectional shape, and a vertical or steep rising surface 2 a is provided on the side surface 3 </ b> E near the base of the U-shaped seal portion 3. And an unequal triangular shape having a slanted inclined surface 2b on the distal end 7a side (external 11 side) of the elastic leg piece 7. In addition, the 2nd seal | sticker protrusion 2 is good also as a cross-sectional shape of the trapezoid mountain shape from which the top part 9 was cut off. In the illustrated example, only one second seal protrusion 2 is formed, but two or more second seal protrusions 2 may be formed (not shown). It is also preferable to coat the second seal protrusion 2 with a metal plating layer of Ag, Cu, Au, Ni or the like. (The same applies to the first seal protrusion 1).

In the second seal protrusion 2, the length L from the outer peripheral surface 4 </ b> A of the bulging portion 4 to the top portion 9 is set to 0.3 mm to 1.2 mm.
If it is less than 0.3 mm, there may be a portion that does not come into contact with the flat surfaces 5 and 6 on the circumference. On the other hand, when it exceeds 1.2 mm, the first seal protrusion 1 comes into contact with the approach of the two planes 5 and 6, and the elastic leg piece 7 is elastically deformed (as shown in FIG. 4). There is a possibility that the second seal protrusion 2 may be separated from the flat surfaces 5 and 6 (not exhibiting the sealing performance) with such elastic deformation.

In addition, guide slope surfaces 8 and 8 are formed at the tip corners of the bulging portions 4 and 4.
That is, it is formed by chamfering the tip corners on the radially outer side of the bulging portions 4 and 4. When the two parallel planes 5 and 6 are gradually approached, the guide gradient surfaces 8 and 8 are guided and guided to the corner portions 20 and 20 of the flange portions 12 and 13, and the present metal seal is applied to the shaft centers of the flange portions 12 and 13. Centering is performed smoothly so that the axial centers of S coincide.

The use method (action) of the metal seal of the present invention described above will be described.
As shown in FIG. 4, in the compression use state, the U-shaped seal portion 3 is compressed into two parallel planes 5 and 6, and the tip portions 7a and 7a of the cantilever-like elastic leg pieces 7 and 7 approach each other. The elastic repulsive forces F and F are generated in the first seal projections 1 and 1 of the tip end portions 7a and 7a by the elastic biasing force of the cantilever-like elastic leg pieces 7 and 7, and the two planes 5 , 6 is sealed (sealed). Although there is an advantage that the present metal seal S can be replaced as it is in the same place of use, the sealing material 36 illustrated in FIG. 8 that has been used conventionally has an advantage in that an elastic repulsive force F is used. 8 is preferably equal to or slightly larger (for example, 1 to 4 times) than the rubber O-ring 39 of the sealing material 36 in FIG. Therefore, it is preferable to set the wall thickness dimension T 7 of the elastic leg pieces 7 and ₇ to be small or to set the radial protrusion dimension to be long.

After the cantilever-like elastic leg pieces 7 and 7 are sufficiently elastically deformed, as shown in FIG. 5, the second seal protrusion 2 is pressed against the flat surfaces 5 and 6 to exhibit the secondary seal (sealing) performance. .
When a high-pressure fluid (corrosion gas such as oxygen plasma or oxygen radical) flows through the inside 10 of the piping joint 14 and the outside 11 has a low pressure, the (vertical) standing surface of the second seal protrusion 2 receive high pressure P ₀ of the internal 10 at 2a, corrosive gases such as oxygen plasma or oxygen radicals to the outside 11 is sealed to prevent leakage. On the other hand, although not shown in the figure, when the atmosphere in the interior 10 is set to a vacuum pressure and the exterior 11 is the atmosphere, the inclined surface 2 of the second seal protrusion 2 receives atmospheric pressure. Since the pressure difference between the outside 11 is relatively small, the sealing performance of the second seal protrusion 2 is not impaired, and the amount of leakage from the outside 11 to the inside 10 is small.
When two second seal protrusions 2 and 2 are provided (not shown), a more reliable sealing performance is exhibited. In addition, by using a plurality of seal protrusions 2 and 2, even if one seal protrusion 2 itself is damaged or the mating flat surfaces 5 and 6 are damaged, the sealing performance is maintained.

  The design of the present invention can be changed. For example, the U-shaped seal portion 3 may change the direction of the elastic leg pieces 7 and 7 between the outer side and the inner side in the radial direction. That is, the pair of elastic leg pieces 7 and 7 may be projected in parallel from the bottom wall portion 3A of the U-shaped seal portion 3 radially inward. The guide slope surfaces 8 and 8 may be formed on the portion, and the inner peripheral surface of the bulging portions 4 and 4 may be used as the centering guide portion G (not shown).

As described above, the metal seal according to the present invention includes the U-shaped seal portion 3 that seals between the two parallel planes 5 and 6, and from the side surfaces 3E and 3E closer to the base of the U-shaped seal portion 3, Since the bulging portions 4 and 4 for locking protrude and the guide portion G for centering is integrally formed, there is no need to process seal grooves in two parallel planes 5 and 6 to be sealed. It is possible to replace the sealing material (see FIG. 8) having the rubber part.
In recent years, the ambient temperature in semiconductor manufacturing equipment and the like has risen, and it often exceeds the heat resistance temperature of the conventional rubber seal (see FIG. 8). The seal of the present invention can be applied as it is without additional modification such as a groove. As described above, the seal according to the present invention can cope with a high temperature region, and greatly contributes to the advancement of technology such as a recent semiconductor manufacturing apparatus.

Further, the first seal protrusion 1 is formed at the distal end portion 7 a of the pair of elastic leg pieces 7 of the U-shaped seal portion 3, and the base-side side surface 3 E and the bulging portion 4 of the U-shaped seal portion 3 are further formed. Since the second seal protrusion 2 smaller than the first seal protrusion 1 is formed on each of the side surfaces 3E and 3E near the base at the corner R, a high atmosphere of the above-described recent semiconductor manufacturing apparatus or the like When used in place of a conventional rubber seal (see FIG. 8) corresponding to the temperature, the elastic force of the elastic leg piece 7 made of metal is set to a small size (depending on the shape and size), and the plane 5 , 6 --- The tightening force of flanges 12 and 13 ---------------- needs to be kept from increasing as compared to rubber seals (see Fig. 8). Thus, setting the elastic force of the elastic leg piece 7 made of metal to a small value means that the first seal Regarding the possibility that the sealing performance (sealing performance) of the strip 1 is lowered and may become unstable, the second sealing projection 2 exerts great power as a secondary seal (supplementary seal), and the first sealing projection 1 In cooperation with the product, it exhibits a stable sealing performance (sealing performance) as a whole.
In other words, use in a high-pressure atmosphere was realized while maintaining the sealing performance (sealing performance) of the conventional rubber seal illustrated in FIG.

  Further, since the guide gradient surfaces 8 and 8 are formed at the tip corners of the bulging portions 4 and 4, the guide gradient surfaces 8 and 8 are slidably contacted and guided by the corner portions 20 and 20 of the planes 5 and 6. Thus, centering (positioning) is performed smoothly and reliably.

  Further, since the second seal protrusion 2 is formed in a triangular or trapezoidal cross-sectional shape, it is pressed against the two planes 5 and 6 locally at an extremely high surface pressure to improve the sealing performance. It fully exerts its role as the secondary seal (supplementary seal).

DESCRIPTION OF SYMBOLS 1 1st seal protrusion 2 2nd seal protrusion 3 U-shaped seal part 3A Bottom wall part 3E Base side side surface 4 Swelling part 5 Plane 6 Plane 7 (cantilever-like) elastic leg piece 7a Tip part 7b Base end Part 8 Guide slope surface G Centering guide part

Claims (4)

  A U-shaped seal portion (3) that seals between two planes (5) and (6) parallel to each other is provided, and the U-shaped seal portion (3) is locked from the side surfaces (3E) and (3E) closer to the base portion. A metal seal characterized by projecting the bulging portions (4) and (4) and integrally forming a centering guide portion (G).   A first seal protrusion (1) is formed at the tip (7a) of the pair of elastic leg pieces (7) of the U-shaped seal portion (3), and further, the U-shaped seal portion (3) has the above-mentioned configuration. At the corner (R) between the base-side side surface (3E) and the bulging portion (4), the base-side side surface (3E) (3E) is smaller than the first seal protrusion (1). The metal seal according to claim 1, wherein a second seal protrusion (2) is formed.   The metal seal according to claim 1 or 2, wherein a guide gradient surface (8) (8) is formed at a tip corner of the bulging portion (4) (4).   The metal seal according to claim 2, wherein the second seal protrusion (2) is formed in a triangular mountain shape or a trapezoidal mountain shape cross-sectional shape.

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