Sealing material for dovetail groove and vacuum gate valve provided with sealing material for dovetail groove

1. A sealing material in a closed circular shape for a dovetail groove to be mounted to a dovetail groove formed on a surface of one member and to be abutted to a surface of another member to seal a space between the one member and the other member in a jointing position of the one member and the other member facing to each other,

the dovetail groove to which the sealing material for the dovetail groove is mounted, in a cross-sectional shape, having an opening portion in which a section close to the surface of the one member is narrowest, and being in a trapezoidal shape expanding in a tapered shape from an edge of the opening portion to a bottom face of the dovetail groove and having a pair of oblique sides and a flat bottom face,

the sealing material for a dovetail groove in a cross-sectional shape comprising:

a bottom portion that comes into contact with the bottom face of the dovetail groove, the bottom portion comprising corner portions formed slightly narrower than the narrowest width of the opening portion of the dovetail groove;

a pair of side protruding portions that is formed continuously from the bottom portion and that is protruded in a width direction from the corner portion of the bottom portion in such a manner that the pair of side protruding portions is abutted to the pair of oblique sides formed inside the dovetail groove;

an overhanging shoulder portion that is formed continuously from the side protruding portions; and

a sealing protrusion that is formed continuously from the overhanging shoulder portion and that is protruded upward from the opening portion of the dovetail groove to seal a space between the one member and the other member in the case in which the sealing protrusion is abutted to the surface of the other member, wherein

a corner portion of the overhanging shoulder portion is positioned closer to the bottom face of the dovetail groove as compared with the position of the side end face of the opening portion of the dovetail groove and is positioned closer to the opening portion side of the dovetail groove as compared with the position of the narrowest section of the dovetail groove.

2. The sealing material for a dovetail groove as defined in claim 1 , wherein the range of W 1 is indicated by 0.75G<W 1 <G in the case in which a width of the widest section of the overhanging shoulder portion for the sealing material for a dovetail groove is W 1 and a width of the narrowest section of the opening portion of the dovetail groove is G.

3. The sealing material for a dovetail groove as defined in claim 1 , wherein the range of H 1 is indicated by 1.20H<H 1 <1.60H in the case in which a distance from the bottom face of the dovetail groove to the side end face of the opening portion of the dovetail groove is H and a distance from the bottom face of the dovetail groove to the top position of the sealing protrusion is H 1 .

4. The sealing material for a dovetail groove as defined in claim 1 , wherein the range of H 2 is indicated by 0.90H<H 2 <0.95H in the case in which a distance from the bottom face of the dovetail groove to the side end face of the opening portion of the dovetail groove is H and a distance from the bottom face of the dovetail groove to the base end portion of the side protruding portion on the side end face side of the opening portion of the dovetail groove is H 2 .

5. The sealing material for a dovetail groove as defined in claim 1 , wherein the range of W 2 is indicated by 0.75G<W 2 <G in the case in which a width of the narrowest section of the opening portion of the dovetail groove is G and a width of the widest section of the bottom portion is W 2 .

6. The sealing material for a dovetail groove as defined in claim 1 , wherein a concave is formed on the bottom portion.

7. The sealing material for a dovetail groove as defined in claim 1 , wherein the sealing material for a dovetail groove bottom portion is in a symmetric shape with respect to a perpendicular line drawn from the top position of the sealing protrusion to the bottom portion.

8. A vacuum gate valve sealing material in a closed circular shape for a dovetail groove to be mounted to a dovetail groove formed on a surface of one member of a gate valve and to be abutted to a surface of another member of the gate valve to seal a space between the both members in a jointing position of a pair of members facing to each other,

the dovetail groove to which the sealing material for the dovetail groove is mounted, in a cross-sectional shape, having an opening portion in which a section close to the surface of the one member is narrowest, and being in a trapezoidal shape expanding in a tapered shape from an edge of the opening portion to a bottom face of the dovetail groove and having a pair of oblique sides and a flat bottom face,

the sealing material for a dovetail groove in a cross-sectional shape comprising:

a bottom portion that comes into contact with the bottom face of the dovetail groove, the bottom portion comprising corner portions formed slightly narrower than the narrowest width of the opening portion of the dovetail groove;

a pair of side protruding portions that is formed continuously from the bottom portion and that is protruded in a width direction from the corner portion of the bottom portion in such a mariner that the pair of side protruding portions is abutted to the pair of oblique sides formed inside the dovetail groove;

an overhanging shoulder portion that is formed continuously from the side protruding portions; and

a sealing protrusion that is formed continuously from the overhanging shoulder portion and that is protruded upward from the opening portion of the dovetail groove to seal a space between the one member and the other member in the case in which the sealing protrusion is abutted to the surface of the other member, wherein

a corner portion of the overhanging shoulder portion is positioned closer to the bottom face of the dovetail groove as compared with the position of the side end face of the opening portion of the dovetail groove and is positioned closer to the opening portion side of the dovetail groove as compared with the position of the narrowest section of the dovetail groove.

9. The vacuum gate valve of claim 8 , wherein the range of W 1 is indicated by 0.75G<W 1 <G in the case in which a width of the widest section of the overhanging shoulder portion for the sealing material for a dovetail groove is W 1 and a width of the narrowest section of the opening portion of the dovetail groove is G.

10. The vacuum gate valve of claim 8 , wherein the range of H 1 is indicated by 1.20H<H 1 <1.60H in the case in which a distance from the bottom face of the dovetail groove to the side end face of the opening portion of the dovetail groove is H and a distance from the bottom face of the dovetail groove to the top position of the sealing protrusion is H 1 .

11. The vacuum gate valve of claim 8 , wherein the range of H 2 is indicated by 0.90H<H 2 <0.95H in the case in which a distance from the bottom face of the dovetail groove to the side end face of the opening portion of the dovetail groove is H and a distance from the bottom face of the dovetail groove to the base end portion of the side protruding portion on the side end face side of the opening portion of the dovetail groove is H 2 .

12. The vacuum gate valve of claim 8 , wherein the range of W 2 is indicated by 0.75G<W 2 <G in the case in which a width of the narrowest section of the opening portion of the dovetail groove is G and a width of the widest section of the bottom portion is W 2 .

13. The vacuum gate valve of claim 8 , wherein a concave is formed on the bottom portion.

14. The vacuum gate valve of claim 8 , wherein the sealing material for a dovetail groove bottom portion is in a symmetric shape with respect to a perpendicular line drawn from the top position of the sealing protrusion to the bottom portion.