JP2015086973A - Seal ring - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a seal ring that does not cause a twist in attachment to a device and use.SOLUTION: A radial cross-sectional shape of a seal ring made of a rubber elastic body comprises two straight sides that are obtained by connecting two line segments together, and an arc part that connects tip points of the straight sides together in an arc shape. The two straight sides have the same length; an internal angle between the straight sides to be connected together is 90°; and the length of the arc part is equivalent to three-fourths of a circumference, the radius of which is equal to the length of the straight side. The two straight sides with the internal angle of 90°are provided to prevent a twist.

Description

  The present invention relates to a seal ring.

There is known a seal ring that is attached to a dovetail groove that is inclined so that only the first inner surface on one side falls to the inside of the groove (Patent Document 1). This seal ring has an insertion portion into the dovetail groove, a side convex surface that is in close contact with the first inner surface, and a bottom surface that can be in close contact with the groove bottom of the dovetail groove and is smaller than the groove width between the groove shoulders In addition, a side elevation surface that is close to the second inner surface opposite to the first inner surface and is inclined so that the bottom surface protrudes is formed.
In addition, there is known a seal ring with a deformed cross section that is attached to a normal dovetail groove whose bottom is expanded from the diameter of the opening (Patent Documents 2 to 4).

  A seal ring having a cross-sectional shape similar to a part of the cross-sectional shape of the dovetail and providing a close-contactable portion in the dovetail is known as shown in Patent Documents 1 to 4, but the cross-sectional shape is There is a problem that it cannot be applied to different dovetails. For example, when the seal ring described in Patent Document 1 is applied to a rectangular-shaped seal ring mounting groove with one side open, that is, a so-called U-shaped seal ring mounting groove, it is effectively prevented from coming off or stress concentration at the contact portion with the groove shoulder is reduced. The effect that it can be prevented is not obtained.

  O-rings, which are conventional round seal rings, are often used for U-shaped seal ring mounting grooves, but this O-ring is inserted into or used in the seal ring mounting groove. Twist is likely to occur due to the applied stress. In addition, there is a problem that even if twisting occurs, it cannot be distinguished from the appearance of the O-ring.

  Further, as the use of the seal ring expands, the seal ring may be attached to the outer peripheral surface of a circular part such as a cylinder or a cylinder. In this case, the diameter of the seal ring is expanded and is often fitted in the seal ring mounting groove provided on the outer peripheral surface of the circular part, so that the seal ring is likely to be twisted during mounting, and the occurrence of twist is difficult to detect. There is.

  In particular, in a seal ring used in a dry etching apparatus used in the manufacturing process of a semiconductor device or a liquid crystal display device, this twisting promotes deterioration of the seal ring, resulting in a problem that the repair period of the dry etching apparatus is shortened. is there.

Japanese Patent No. 4962687 JP 2008-180293 A JP 2004-316724 A JP-T 9-510286

  The present invention has been made to cope with such problems, and an object of the present invention is to provide a seal ring that does not cause twisting when mounted on and used in the apparatus.

The seal ring of the present invention is made of a rubber elastic body. The radial cross-sectional shape of this seal ring is characterized by comprising two straight sides obtained by connecting two line segments and an arc portion that joins the end points of the two straight sides in an arc shape. To do.
In particular, the two straight sides have the same length. Further, the inner angle of the two straight sides is 90 °, and the arc portion is an arc having a length of 3/4 of a circumference with the length of the straight side as a radius.

  Since the seal ring of the present invention is composed of two straight sides and an arc portion joined in an arc shape, the plane constituted by the straight sides of the seal ring may be in close contact with the plane portion in the seal ring mounting groove. it can. Therefore, the twist at the time of use of a seal ring is prevented, and the sealing property of a seal ring improves. Further, since the non-uniformity of internal stress due to twisting is alleviated, the service life of the seal ring is improved. Therefore, the time for inspection and repair of the dry etching apparatus can be improved.

It is a figure which shows a seal ring. It is a figure which shows the cross-sectional shape of another seal ring. It is sectional drawing of the groove | channel with which the seal ring was mounted | worn. It is sectional drawing with which the seal ring was mounted | worn with the groove | channel provided in the outer peripheral surface of circular components.

An example of the seal ring of the present invention will be described with reference to FIG. 1A is a plan view of the seal ring, and FIG. 1B is a cross-sectional view taken along the line AA.
As shown in FIG. 1A, the seal ring 1 has a rubber elastic body formed into an annular shape.
As shown in FIG. 1 (b), the radial cross-sectional shape of the seal ring 1 is such that two straight sides forming an L shape by connecting the line segment 2 and the line segment 3 at the intersection point 4 are the seal ring 1. It constitutes a part of the outer periphery. The internal angle α at the intersection 4 is 90 °. Further, the entire outer periphery of the seal ring 1 is formed with the tip point 2 a of the line segment 2 and the tip point 3 a of the line segment 3 as both end points of the arc portion 5. The lengths of the line segment 2 and the line segment 3 correspond to the radius of the arc portion 5 respectively. That is, the arc portion 5 is an arc having a length that is 3/4 of the length of the circumference with the length of the line segment 2 and the line segment 3 as the radius.

  The seal ring shown in FIG. 1 (a) has two straight sides connected at the intersection 4 at an inner angle α of 90 ° with the line segment 2 and the line segment 3 attached to the seal ring mounting groove. In doing so, the straight side comes into contact with the inner side surface and the bottom surface of the groove, so that the closeness is improved and the seal ring itself is not twisted. Further, even when the seal ring is expanded and mounted in the seal ring mounting groove provided on the outer peripheral surface of the circular part, the seal ring is not twisted during mounting.

  When mounting in a U-shaped seal ring mounting groove, the two straight sides are configured such that at least one of the straight sides is in close contact with the bottom surface of the groove. Further, when a groove is formed on the cylindrical inner surface, a straight side is provided on the outer peripheral surface of the seal ring.

As a cross-sectional shape having two straight sides and an arc portion obtained by connecting two line segments, for example, the shapes shown in FIGS. 2A to 2C other than the shape shown in FIG. Can be mentioned.
The cross-sectional shape shown in FIG. 2A is a case where the lengths of the line segment 2 and the line segment 3 exceed the radius of the circumference forming the arc portion 5. By making the straight side longer, it becomes easier to closely contact the seal ring mounting groove.
The cross-sectional shape shown in FIG. 2B is a case where the lengths of the line segment 2 and the line segment 3 are different. When the seal ring mounting groove is shallow, it can be used according to the shape of the groove.
The cross-sectional shape shown in FIG. 2C is a case where the internal angle α exceeds 90 °. This can be applied when the shape of the seal ring mounting groove is a wedge shape, and the inner angle α can be less than 90 ° depending on the shape of the groove.

A method of mounting the seal ring shown in FIG. 1A in the seal ring mounting groove will be described with reference to FIGS. FIG. 3 is a sectional view of the groove in which the seal ring is mounted. FIG. 4 is a cross-sectional view in which a seal ring is mounted in a groove provided on the outer peripheral surface of a circular component.
As shown in FIG. 3, the seal ring 1 of the present invention can be mounted in a seal ring mounting groove 6 having a U-shaped cross section in the same manner as a conventional O-ring having a perfect circular cross section. The attached seal ring 1 is in close contact with the bottom surface portion 6a of the seal ring mounting groove 6 at the line segment 2 and the side surface portion 6b of the seal ring mounting groove 6 at the line segment 3. When the part 7 in which the seal ring 1 is mounted in the groove 6 is pressed against the other part 8, the arc part 5 of the seal ring 1 and the other part 8 are brought into close contact with each other. Is sealed. Since the seal ring 1 is in close contact with the bottom surface and the side surface portion of the seal ring mounting groove 6 even when a pressing force is applied, it does not twist.

  As shown in FIG. 4, the seal ring 1 of the present invention has two straight sides and one circular arc, even in the case of a circular component 9 in which a circular ring-shaped seal ring mounting groove is provided on the outer peripheral surface of the circular component. Since it is composed of parts, it can be easily mounted without twisting. The seal ring 1 is in close contact with the bottom surface portion 6a of the seal ring mounting groove 6 at the line segment 3 and the side surface portion 6b of the seal ring mounting groove 6 at the line segment 2. Since the lengths of the line segment 2 and the line segment 3 are the same, the seal ring mounting groove shown in FIG. 3 or the seal ring mounting groove shown in FIG. it can.

  In the seal ring 1 shown in FIG. 1 (a), the arc portion occupies a length of 3/4 of the length of the entire circumferential portion, and the circumferential portion is the majority, so that the O-ring having a perfectly circular cross section is used. Can be used as For example, it can be used for dovetail grooves, vacuum flange grooves, and triangular grooves other than the U-shaped seal ring mounting groove. Even if the seal ring mounting groove has a special cross section, it can be used as long as at least the bottom surface of the groove is flat.

The seal ring of the present invention is a rubber elastic body obtained by molding a rubber composition.
Usable rubber compositions are nitrile rubber (NBR), styrene / butadiene rubber (SBR), silicone rubber (VMQ), fluoro rubber (FKM), ethylene / propylene rubber (EPDM), chloroprene rubber (CR), butyl rubber (IIR). ), Acrylic rubber (ACM), hydrogenated NBR (HNBR), perfluoroelastomer (FFKM) and other rubber raw materials, vulcanizing agent, vulcanization accelerator, anti-aging agent, carbon black, organic or inorganic filler, etc. It is obtained by blending. The rubber raw material can be used alone or as a blend rubber.
As the nitrile rubber (NBR), any of extremely high nitrile rubber, high nitrile rubber, medium / high nitrile rubber, medium nitrile rubber, and low nitrile rubber can be used. A nitrile content nitrile rubber (NBR) having a nitrile content of 31 to 35% is preferred.
Perfluoroelastomer (FFKM), a material for semiconductor and liquid crystal manufacturing processes such as dry etching and CVD, is a copolymer of perfluoroolefin, perfluoroalkyl vinyl ether, and iodine and / or bromine-containing vinyl monomers. is there.

  The compounding agent blended with the rubber raw material is selected and blended according to each rubber raw material. For example, for perfluoroelastomer (FFKM), a peroxide as a vulcanizing agent, a polyvalent allyl compound as a vulcanization aid, and a polytetrafluoroethylene powder, a silicon oxide powder or the like as a filler are blended. .

The rubber composition is vulcanized in a seal ring-shaped mold to produce a seal ring made of a rubber elastic body.
As the vulcanization conditions, optimum conditions for the rubber composition are selected. For example, in the case of the perfluoroelastomer (FFKM) composition, the vulcanization conditions include primary vulcanization at a vulcanization temperature of 150 to 170 ° C., vulcanization time of 5 to 30 minutes, and secondary vulcanization of 170 to 250. A vulcanization time of 4 to 48 hours at a vulcanization temperature of ° C is preferred. In particular, from the viewpoint of energy saving, 2 to 5 hours are preferable at a vulcanization temperature of 170 to 200 ° C.

The seal ring of the present invention can be used as an alternative to the O-ring defined in Japan Industrial (JIS) standard, ISO standard, JASO standard and the like.
In addition, since no twist is generated, it is suitable for a perfluoroelastomer (FFKM) seal ring that easily generates twist for semiconductor and liquid crystal manufacturing processes such as dry etching and CVD.
The dry etching apparatus can be suitably used for a plasma etching apparatus, a reactive ion etching apparatus, a reactive ion beam etching apparatus, a sputter etching apparatus, an ion beam etching apparatus, and the like.

  The seal ring of the present invention is an alternative to the O-ring as a seal ring that does not twist as compared with the conventional O-ring.

DESCRIPTION OF SYMBOLS 1 Seal ring 2 Line segment 3 Line segment 4 Intersection 5 Arc part 6 Seal ring installation groove 7 Parts 8 Other parts 9 Circular part provided with seal ring installation groove

Claims (3)

A seal ring made of a rubber elastic body,
The radial cross-sectional shape of the seal ring includes two straight sides obtained by connecting two line segments, and an arc portion that joins the end points of the two straight sides in an arc shape. Seal ring.   The seal ring according to claim 1, wherein the two straight sides have the same length.   The internal angle of the two straight sides to be connected is 90 °, and the arc portion is an arc having a length of 3/4 of a circumference with the length of the straight side as a radius. The seal ring according to claim 1 or 2.

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