JP2008138744A - Dovetail groove - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dovetail groove which suppresses the occurrence of particles from a sealing material and a deterioration in sealability of a sealing material due to twist, and provides a long service life of the sealing material by suppressing the twist. <P>SOLUTION: A dovetail groove is employed for maintaining hermeticity between the joint surfaces of two members coming into contact with each other through sealing members 20 equipped therewith. In a cross-sectional shape, a groove maximum width part 14 formed by respectively swelling both groove side surface parts 13 to both sides in the width direction from a groove opening part 11 and a groove bottom part 12, is included in an intermediate height part of a dovetail groove space. The surface between the groove maximum width part 14 and the groove bottom part 12 in both the groove side surface parts 13 is at least brought into contact with the sealing material 20 in a pressed state. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a dovetail groove. Specifically, the present invention relates to a dovetail groove in which a sealing material for sealing a joint portion between members is mounted in a vacuum apparatus or piping equipment.

A seal structure is provided at a joint portion between members requiring airtightness. As one of such seal structures, there is a technology that uses a dovetail groove. Specifically, a dovetail groove is provided in one member, a sealant is attached to the dovetail groove, and then joined to the other member. Fixing with bolts or the like is performed. The dovetail groove has, for example, a substantially trapezoidal cross section, that is, a shape in which the widths of both groove side surfaces are widened from the groove opening to the groove bottom in order to prevent the sealant from falling off or protruding. Is generally used.
For example, Patent Document 1 discloses a dovetail seal material that does not easily cause problems such as biting and twisting and has an excellent sealing function, but the cross-sectional shape of the dovetail groove used therein is substantially trapezoidal. belongs to. By twisting the configuration of the sealing material, twisting of the sealing material is suppressed as compared with a conventional sealing material such as an O-ring.
Japanese Patent Laid-Open No. 2003-14126

If the sealing material is devised as in the prior art, twisting of the sealing material can surely be suppressed, but it is difficult to say that sufficient suppression is possible. The reason is as follows.
That is, in the conventional technology, when mounting the sealing material on the dovetail groove having a substantially trapezoidal cross section, the distance between both ends of the bottom of the sealing material is approximately the same as the groove opening width in consideration of the ease of the mounting operation. Or it is usually designed to be narrower than the groove opening width, and since the dovetail groove is substantially trapezoidal, the distance between both ends of the bottom of the sealing material becomes narrower than the bottom face width of the dovetail groove. Even at this time, a gap is formed between the dovetail groove and the sealing material at the side surface near the bottom surface. As a result, for example, if the pressure applied at the time of pressing is non-uniform on the left and right, there is a possibility that the seal material tilts toward one of the gaps, which may cause twisting. When the sealing material is compressed in such a state where the twist is generated, the sealing material is worn by the dovetail groove to generate particles, and is damaged to shorten the life. Furthermore, in addition to the breakage of the sealing material, there is also a decrease in stress and variations, resulting in a decrease in the sealing performance of the sealing material.

  Therefore, the problem to be solved by the present invention is to solve the above-mentioned problems without losing the advantage of the substantially trapezoidal dovetail that prevents the seal material from dropping off or protruding, and thus does not cause twisting. It is an object of the present invention to provide a dovetail groove that can suppress generation of particles from the sealing material due to the twist and a decrease in sealing performance of the sealing material, and can realize a long life of the sealing material.

  The present inventors have intensively studied to solve the above problems, and in the process, devised the sealing material to change the idea from the conventional idea of solving various problems such as torsion, As a result of making trial manufactures of dovetails of various configurations and repeating further studies, in the cross-sectional shape, dovetails having a groove bottom surface portion, a groove maximum width portion, and a groove side surface portion were used. If the shape and dimensions are devised, the seal material can be prevented from falling off or protruding, and the seal material can be prevented from moving in the dovetail to reduce torsion, thereby reducing friction between the dovetail and the seal material. Thus, it has been found that the generation of particles and the deterioration of sealing performance due to wear of the sealing material can be suppressed, and that the life of the sealing material can be extended, and the present invention has been completed.

  That is, the dovetail according to the present invention is a dovetail used to maintain the airtightness between the joint surfaces of the two members that are in contact with each other with the sealing material attached, and is in the middle of the dovetail space in the cross-sectional shape. In the height portion, both groove side surfaces are provided with a groove maximum width portion formed by bulging from the groove opening portion and the groove bottom surface to both sides in the width direction, and the groove maximum width portion and the groove in the both groove side surfaces. The surface between the bottom portions is designed to be in contact with at least the sealing material in the pressed state.

  According to the present invention, it is possible to suppress the movement of the sealing material mounted in the dovetail and suppress the twist while suppressing the dropout and protrusion of the sealing material, and accordingly, the seal material is worn due to the twist. Particles caused by the cause and a decrease in sealing performance can be suppressed, and damage to the sealing material can be avoided to extend the life of the sealing material.

Hereinafter, the dovetail groove according to the present invention will be described in detail with reference to the drawings. Changes can be made.
FIG. 1 is a cross-sectional view of a dovetail groove showing an embodiment of the present invention. FIG. 2 is a schematic diagram showing the dimensional structure of the dovetail. FIG. 3 is a cross-sectional view showing an example of the use state of the dovetail.
As shown in FIG. 1, the dovetail groove 10 according to the present invention includes a groove opening portion 11, a groove bottom surface portion 12, and a groove side surface portion 13, and further includes a groove maximum width portion 14 at an intermediate height portion of the dovetail space. I have. The dovetail groove 10 is used with a sealing material 20 mounted.

The overall shape of the sealing material 20 is not particularly limited, and examples thereof include a circular shape, an elliptical shape, and a track shape, and the cross-sectional shape is not particularly limited. What is necessary is just to design the ring diameter of the sealing material 20, the arrangement | positioning shape of a ring, etc. so that it may match the ring diameter of the dovetail groove | channel 10, the arrangement shape of a ring, etc. Or you may design so that the ring diameter of the dovetail groove | channel 10, the arrangement | positioning shape of a ring, etc. may match the ring diameter, the arrangement | positioning shape of a ring, etc. of the sealing material 20.
As the sealing material 20, for example, a sealing material having a hypotenuse that rises obliquely upward from both sides of the bottom in the cross-sectional shape can be used. As shown in FIGS. 1 to 3, for example, as described in Patent Document 1, it is difficult to cause biting or twisting, and a cross-sectional shape having an excellent sealing function is used with a dharma-type sealing material. it can. In this case, the surface between the groove maximum width portion 14 and the groove bottom surface portion 12 in both groove side surfaces 13, 13 of the dovetail groove 10 (hereinafter referred to as the bottom surface side both groove side surfaces) corresponds to the oblique side of the sealing material 20. If the slope is a slope, the contact area between the sealing material 20 and the dovetail groove 10 in the pressed state is increased, and the movement of the sealing material 20 is further suppressed and twisting is less likely to occur. The oblique sides of the sealing material 20 and both side surfaces of the bottom surface of the dovetail groove 10 are usually the same in the right and left, but they may be different and may be linear or curved. . Not only the bottom 21 of the sealing material is flat, but also a part of the bottom 21 of the sealing material may be provided with a recess or a groove.

As a material of the sealing material 20, a natural or synthetic rubber material, an elastic resin material, or the like can be used as long as it is an elastic material capable of elastic deformation required for a sealing function. Specifically, it may be appropriately selected and used according to the conditions of the environment to be sealed (conditions such as the type of fluid, temperature, and pressure). Although not particularly limited, for example, in the semiconductor field, when used as an opening / closing lid portion of a drying chamber, EPDM rubber having excellent alcohol resistance and cleanliness and relatively low cost can be used. In corrosive environments such as various plasma conditions, fluororubber is preferred.
The width W1 of the groove opening 11 is preferably designed wider than the distance W4 between both ends of the sealing material bottom 21. As shown in FIG. 3A, the sealing material 20 is mounted in the dovetail groove 10. By satisfying the above conditions, the sealing material bottom 21 can be smoothly inserted into the groove opening 11. If the edge of the groove opening 11 is arc-shaped rounded or chamfered, the sealing material bottom 21 can be inserted into the groove opening 11 more smoothly, which is more preferable. In addition, this leads to suppression of wear of the sealing material 20, which in turn contributes to suppression of generation of particles and deterioration of the sealing property and extension of the life of the sealing material 20.

It is preferable to design the width W2 of the groove bottom surface portion 12 to be 1.0 to 1.1 times the distance W4 between both ends of the sealing material bottom portion 21 in the non-pressed state. As described above, when the width W2 of the groove bottom surface portion 12 is approximately the same as the distance W4 between both ends of the sealing material bottom portion 21 in the non-pressed state, the groove bottom surface portion 12 is compressed when the sealing material 20 is compressed by pressing. The seal material bottom 21 comes in contact with a wide area range of the seal material, and not only can the sealing performance and the twist of the seal material be suppressed, but also the seal material 20 can be formed over a wide area range of the groove side surface portion 13 near the groove bottom surface portion 12. Since the side portions can be brought into contact with each other, the movement of the sealing material 20 in the dovetail groove 10 can be further suppressed.
Both side surfaces of the bottom side grooves are designed to contact at least the sealing material 20 in the pressed state. As long as the bottom side groove side surfaces are designed to come into contact with the sealing material 20 in the pressed state, they may or may not be in contact with the sealing material 20 in the non-pressed state. In the pressed state, since pressure is received from both the opening side and the bottom surface side, the seal material side surface is greatly deformed so as to swell outward, particularly in the vicinity of the center. At this time, if the method of applying pressure is not uniform, the sealing material 20 tends to cause a rotational motion with one end of the sealing material bottom 21 as a fulcrum. In this case, if the trapezoidal dovetail having a substantially trapezoidal shape that has been conventionally used is present, a gap exists between the both sides of the dovetail near the bottom surface of the dovetail groove and the sealant is twisted. However, in the present invention, since the sealing material 20 is in contact with the side surfaces of both grooves on the bottom side, a force that resists rotational energy that causes twisting acts on the contact portion. Therefore, twist is suppressed.

Furthermore, it is preferable that both opening side groove side surfaces are designed to contact at least the sealing material 20 in the pressed state. As long as the opening side groove side surfaces are designed to come into contact with the sealing material 20 in the pressed state, they may or may not be in contact with the sealing material 20 in the non-pressed state. If the opening side both groove side surfaces of the dovetail groove 10 are designed in this way, the sealing material 20 contacts the dovetail groove 10 at both the opening side and the bottom surface side of both groove side surface portions 13 and 13, that is, at four locations. As a result, the movement of the sealing material 20 in the dovetail groove 10 is further suppressed, so that twisting is further suppressed.
The groove side surface portion 13 bulges from the groove opening portion 11 and the groove bottom surface portion 12 to both sides in the width direction to form a groove maximum width portion 14 in the hollow height portion of the dovetail space. In this way, the groove maximum width portion 14 is provided in the hollow height portion of the dovetail space, and the width of the groove opening 11 and the groove bottom surface portion 12 is designed to be relatively narrow, so that the sealing material 20 falls off or protrudes, The movement of the dovetail 10 can be suppressed.

As shown in FIG. 2A, the inclination angle formed by the bottom side groove side surfaces with respect to the perpendicular from the groove bottom surface portion 12 is θ1, and as shown in FIG. It is preferable that the following condition is satisfied in the non-pressed state when an inclination angle formed with respect to the perpendicular from the sealing material bottom 21 is θ2.
10 ° ≦ θ1 ≦ 40 °
0 ° ≦ θ1-θ2 ≦ 10 °
When the angle θ1 is less than 10 °, the width of the groove opening 11 is narrowed or not so, when θ3 (opening side both groove side surfaces are the groove opening 12 shown in FIG. It is necessary to reduce the inclination angle formed with respect to a perpendicular from a straight line passing through the left and right edges of the. If the groove opening 11 is too narrow, it is difficult to mount the sealing material 20, and if the θ3 is small, the sealing material 20 may easily drop off or protrude, which is not preferable in any case. If the angle θ1 exceeds 40 °, the twist of the sealing material 20 may not be sufficiently suppressed, and the tendency becomes stronger as θ1 is larger. In the contact surface between the sealing material 20 and the bottom side groove both side surfaces when the sealing material 20 is compressed by pressing, the reaction force exerted on the sealing material 20 by the bottom side groove side surfaces becomes larger as θ1 increases. The contribution to the width direction of the sealing material 20 is small, and conversely, the contribution to the direction orthogonal to the width direction is large. This is because it becomes difficult to suppress.

When the difference between θ1 and θ2 is less than 0 °, that is, θ2 is larger than θ1, it is difficult to attach the sealing material 20 to the dovetail groove 10. Moreover, when the difference between the θ1 and the θ2 exceeds 10 °, the bottom side dovetail side surfaces are difficult to contact the sealing material 20 in the pressed state. Thus, the difference between θ1 and θ2 affects the occupation ratio of the sealing material 20 to the dovetail groove 10 in the non-pressed state. In consideration of the ease of mounting operation, the stability of the posture of the sealing material 20 in the dovetail groove 10, the elasticity of the sealing material 20, the value of θ2, etc., preferably θ1 may be appropriately selected and determined within the above range.
The vertical height H2 from the groove bottom surface portion 12 to the groove maximum width portion 14 is preferably in the range of 60 to 75% of the groove depth H1. If the ratio of H2 to the entire groove depth H1 exceeds 75%, the length of both side surfaces of the groove on the opening side decreases as the ratio increases, and the cross-sectional shape of the groove approaches a substantially inverted trapezoidal shape. Therefore, it may be difficult to sufficiently prevent the sealing material 20 from dropping or protruding. If the ratio of H2 to the entire groove depth is less than 60%, the lengths of both side surfaces of the opening side groove become longer. Therefore, it is necessary to reduce the angle θ3 or to narrow the width W1 of the groove opening 11. Yes, if the θ3 is small, the sealing material 20 is likely to drop off or protrude, and if the groove opening 11 is too narrow, it may be difficult to mount the sealing material 20. It is not preferable.

  As shown by a two-dot chain line in FIG. 3A, the sealing material 20 is attached to the dovetail groove 10 from the bottom 21 of the sealing material. As described above, if the width W1 of the groove opening 11 is made wider than the distance W4 between both ends of the seal material bottom 21, and the edge of the groove opening 11 is arc-shaped and chamfered, The sealing material bottom 21 passes through the groove opening 11 very smoothly. Normally, the maximum width portion of the sealing material 20 is designed to be wider than the groove opening 11 so that the sealing material 20 does not fall off or protrude from the dovetail groove 10, but it slides from the bottom 21 of the sealing material. When the dovetail groove 10 is inserted, the sealant 20 naturally elastically deforms even when the maximum width portion of the sealant 20 passes through, and the sealant 20 is made into the dovetail groove 10 with almost no resistance. Can be installed.

Next, as shown in FIG. 3 (b), in an actual use state, the sealing material 20 attached to the dovetail groove 10 is pressed by the mating member 30 to compress the sealing material 20, and then tightened bolts or the like. The member provided with the dovetail groove 10 and the mating member 30 are joined and integrated using (not shown).
As described above, when the sealing material 20 is pressed by the mating member 30, first, the sealing material 20 is moved outward as the sealing material upper surface portion 22 comes into contact with the mating member 30 and is pressed toward the groove bottom surface portion 12. Deforms to swell. Next, the bottom surface side groove side surfaces are brought into contact with the sealing material 20 by deformation of the sealing material 20 to the outside. Thereby, the force which resists the force which the sealing material 20 tries to twist arises in the said contact part, and it becomes difficult to produce a twist. In particular, in FIG. 3B, the bottom side groove side surfaces are inclined surfaces corresponding to the oblique sides of the sealing material 20, and the opening side groove side surfaces are in contact with the sealing material 20. It can be seen that the material 20 is in contact with the dovetail on almost the entire side surface, and there is almost no spatial margin for twisting the sealing material 20.

  As described above, the dovetail groove according to the present invention in which twisting of the sealing material is unlikely to occur is suitably used, for example, at a joint between a chamber body and an opening / closing lid of a processing chamber used in a semiconductor / liquid crystal manufacturing process. Moreover, it can also be used for the attachment part of the gate valve which can be opened and closed provided in such a processing chamber. In addition, it can also be suitably used for an opening / closing lid such as a vacuum device, an attachment location of an accessory device, a connection location of piping equipment, and the like.

  The dovetail groove according to the present invention is equipped with a sealing material for sealing a joint portion between members used in the apparatus or equipment in an industrial field where high airtightness is required, such as a vacuum apparatus or piping equipment. It can be suitably used as a dovetail.

It is sectional drawing which shows one Embodiment of the dovetail concerning this invention. It is a schematic diagram which shows the dimensional structure of a dovetail. It is sectional drawing which shows the use condition of a dovetail.

Explanation of symbols

10 Dovetail groove 11 Groove opening 12 Groove bottom surface portion 13 Groove side surface portion 14 Groove maximum width portion 20 Seal material 21 Seal material bottom portion 22 Seal material upper surface portion 30 Mating member W1 Groove opening width W2 Groove bottom width W3 Seal material maximum width W4 Seal Distance H1 between both ends of the bottom of the material H1 Groove depth H2 Vertical height θ1 from the bottom of the groove to the maximum width of the groove θ1 Inclination angle θ2 formed by both side surfaces of the bottom surface side with respect to the perpendicular from the bottom surface of the groove Inclination angle θ3 made with respect to the perpendicular from the bottom of the sealing material Inclination angle made with respect to the perpendicular from the straight line passing through the right and left edges of the groove opening on both sides

Claims (6)

A dovetail groove used to maintain the airtightness between the joint surfaces of the two members that are in contact with each other with the sealing material attached thereto,
In cross-sectional shape,
In the middle height portion of the dovetail space, both groove side surfaces are provided with a groove maximum width portion formed by bulging from the groove opening portion and the groove bottom surface to both sides in the width direction,
The surface between the groove maximum width portion and the groove bottom surface portion in the both groove side surfaces is designed to be in contact with at least a sealing material in a pressed state,
Ant groove characterized by that.   The dovetail groove according to claim 1, wherein a width dimension of the groove bottom portion is 1.0 to 1.1 times a distance between both ends of the bottom portion of the sealing material in a non-pressed state.   The dovetail groove according to claim 1 or 2, wherein a surface between the groove maximum width portion and the opening portion in both groove side surfaces is designed so as to be in contact with at least a sealing material in a pressed state. The surface between the groove maximum width portion and the groove bottom surface portion of the both groove side surfaces has an inclination angle θ1 with respect to the perpendicular from the groove bottom surface portion, and both the sealing material side surfaces are perpendicular to the sealing material bottom portion. The dovetail groove according to any one of claims 1 to 3, which satisfies the following condition in a non-pressed state when an inclination angle formed by the arm is θ2.
10 ° ≦ θ1 ≦ 40 °
0 ° ≦ θ1-θ2 ≦ 10 °   The dovetail groove according to any one of claims 1 to 4, wherein a vertical height from the groove bottom surface portion to the groove maximum width portion is in a range of 60 to 75% of a groove depth.   In the case where a sealing material having a hypotenuse that rises obliquely upward from both sides of the bottom in the cross-sectional shape is used, the surface between the maximum groove width portion and the bottom surface of the groove also corresponds to the hypotenuse of the sealing material. The dovetail groove according to any one of claims 1 to 5, wherein the dovetail is an inclined surface.

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