Spherical annular seal member and method of manufacturing the same

Patent metadata

Field	Value
Publication number	US-9759328-B2
Application number	US-201314429098-A
Country	US
Kind code	B2
Filing date	Aug 22, 2013
Priority date	Oct 16, 2012
Publication date	Sep 12, 2017
Grant date	Sep 12, 2017

Abstract

A spherical annular seal member 38 is used in an exhaust pipe joint and includes a spherical annular base member 36 defined by a cylindrical inner surface 32 , a partially convex spherical surface 33 , large- and small-diameter side annular end faces 34 and 35 of the partially convex spherical surface 33 , and an outer layer 37 formed integrally on the partially convex spherical surface 33 of the spherical annular base member 36 . The spherical annular base member 36 includes a reinforcing member made from a metal wire net 5 and a heat-resistant material containing expanded graphite filling meshes of the metal wire net 5 of this reinforcing member and compressed in such a manner as to be formed integrally with this reinforcing member in mixed form. In the outer layer 37 , the reinforcing member, the heat-resistant material, and the solid lubricant are integrated in mixed form.

First claim

The invention claimed is:

1. A spherical annular seal member for use in an exhaust pipe joint, comprising: a spherical annular base member defined by a cylindrical inner surface, a partially convex spherical surface, and large- and small-diameter side annular end faces of said partially convex spherical surface; and an outer layer formed integrally on said partially convex spherical surface of said spherical annular base member,
wherein said spherical annular base member includes a reinforcing member made from a metal wire net and a heat-resistant material containing expanded graphite and compressed in such a manner as to fill meshes of the metal wire net of said reinforcing member and to be integrated with said reinforcing member in mixed form,
wherein, in said outer layer, a heat-resistant material containing expanded graphite, a solid lubricant consisting of a lubricating composition containing a polytetrafluoroethylene resin, a tetrafluoroethylene-hexafluoropropylene copolymer, and hexagonal boron nitride, and a reinforcing member made from a metal wire net are compressed such that said heat-resistant material and said solid lubricant are filled in meshes of said reinforcing member, and such that said reinforcing member, said heat-resistant material, and said solid lubricant are integrated in mixed form, and
wherein, in a ternary composition diagram of the polytetrafluoroethylene resin, the tetrafluoroethylene-hexafluoropropylene copolymer, and the hexagonal boron nitride, a composition ratio of the polytetrafluoroethylene resin, the tetrafluoroethylene-hexafluoropropylene copolymer, and the hexagonal boron nitride in the lubricating composition falls within a numerical range corresponding to an interior region bounded by a quadrangle having as vertices a composition point with 10% by mass of the polytetrafluoroethylene resin, 10% by mass of the tetrafluoroethylene-hexafluoropropylene copolymer, and 80% by mass of the hexagonal boron nitride, a composition point with 10% by mass of the polytetrafluoroethylene resin, 45% by mass of the tetrafluoroethylene-hexafluoropropylene copolymer, and 45% by mass of the hexagonal boron nitride, a composition point with 45% by mass of the polytetrafluoroethylene resin, 45% by mass of the tetrafluoroethylene-hexafluoropropylene copolymer, and 10% by mass of the hexagonal boron nitride, and a composition point with 40% by mass of the polytetrafluoroethylene resin, 10% by mass of the tetrafluoroethylene-hexafluoropropylene copolymer, and 50% by mass of the hexagonal boron nitride.

2. The spherical annular seal member according to claim 1 , wherein, in the ternary composition diagram of the polytetrafluoroethylene resin, the tetrafluoroethylene-hexafluoropropylene copolymer, and the hexagonal boron nitride, the composition ratio of the polytetrafluoroethylene resin, the tetrafluoroethylene-hexafluoropropylene copolymer, and the hexagonal boron nitride in the lubricating composition falls within a numerical range corresponding to an interior region bounded by a hexagon having as vertices a composition point with 25% by mass of the polytetrafluoroethylene resin, 15% by mass of the tetrafluoroethylene-hexafluoropropylene copolymer, and 60% by mass of the hexagonal boron nitride, a composition point with 12% by mass of the polytetrafluoroethylene resin, 28% by mass of the tetrafluoroethylene-hexafluoropropylene copolymer, and 60% by mass of the hexagonal boron nitride, a composition point with 10% by mass of the polytetrafluoroethylene resin, 40% by mass of the tetrafluoroethylene-hexafluoropropylene copolymer, and 50% by mass of the hexagonal boron nitride, a composition point with 20% by mass of the polytetrafluoroethylene resin, 40% by mass of the tetrafluoroethylene-hexafluoropropylene copolymer, and 40% by mass of the hexagonal boron nitride, a composition point with 38% by mass of the polytetrafluoroethylene resin, 22% by mass of the tetrafluoroethylene-hexafluoropropylene copolymer, and 40% by mass of the hexagonal boron nitride, and a composition point with 35% by mass of the polytetrafluoroethylene resin, 15% by mass of the tetrafluoroethylene-hexafluoropropylene copolymer, and 50% by mass of the hexagonal boron nitride.

3. The spherical annular seal member according to claim 1 , wherein said lubricating composition further contains hydrated alumina at a ratio of not more than 20% by mass.

4. The spherical annular seal member according to claim 1 , wherein said heat-resistant material contains a phosphate at a ratio of 0.1 to 16% by mass.

5. The spherical annular seal member according to claim 1 , wherein said heat-resistant material contains phosphorus pentoxide at a ratio of 0.05 to 5% by mass.

6. The spherical annular seal member according to claim 1 , wherein an outer surface of said outer layer is formed into a smooth surface in which areas constituted by said reinforcing member and areas constituted by said solid lubricant are present in mixed form.

7. The spherical annular seal member according to claim 1 , wherein an outer surface of said outer layer is formed into a smooth surface constituted by said solid lubricant covering said reinforcing member.

8. The spherical annular seal member according to claim 1 , wherein said solid lubricant consists of an unsintered lubricating composition.

9. The spherical annular seal member according to claim 1 , wherein said solid lubricant consists of a sintered lubricating composition.

10. A method of manufacturing a spherical annular seal member for use in an exhaust pipe joint and including a spherical annular base member defined by a cylindrical inner surface, a partially convex spherical surface, and large- and small-diameter side annular end faces of said partially convex spherical surface, and an outer layer formed integrally on said partially convex spherical surface of said spherical annular base member, comprising the steps of:
(a) preparing an expanded graphite sheet serving as a heat-resistant material;
(b) preparing a metal wire net serving as a reinforcing member and obtained by weaving or knitting a fine metal wire, and, after forming a superposed assembly by superposing said metal wire net on said expanded graphite sheet, convoluting said superposed assembly into a hollow cylindrical shape, to thereby form a tubular base member;
(c) preparing an aqueous dispersion of a lubricating composition consisting of a polytetrafluoroethylene resin powder, a tetrafluoroethylene-hexafluoropropylene copolymer powder, a hexagonal boron nitride powder, a surfactant, and water;
(d) preparing another expanded graphite sheet serving as a heat-resistant material, applying said aqueous dispersion onto one surface of said other expanded graphite sheet, and drying the same, to thereby form on a surface of said other expanded graphite sheet a coating layer of a solid lubricant consisting of a polytetrafluoroethylene resin, a tetrafluoroethylene-hexafluoropropylene copolymer, and hexagonal boron nitride;
(e) superposing said other expanded graphite sheet having said coating layer on another metal wire net serving as a reinforcing member and obtained by weaving or knitting a fine metal wire, and pressurizing a superposed assembly of said other expanded graphite sheet and said other metal wire net by a pair of rollers, to thereby form a flattened outer-layer forming member in which said other expanded graphite sheet and said coating layer are filled in meshes of said other metal wire net;
(f) convoluting said outer-layer forming member around an outer peripheral surface of said tubular base member with its coating layer facing outside, to thereby form a cylindrical preform; and
(g) fitting said cylindrical preform over an outer peripheral surface of a cor

Assignees

• Oiles Industry Co Ltd

Inventors

• Yoshida Atsushi
• Satou Eiji
• Shionoya Shin-Ichi
• Koibuchi Ryota

Classifications

• C09K3/1009 Primary

  Fluorinated polymers, e.g. PTFE · CPC title

• F16J15/104 Primary

  characterised by structure · CPC title

• C09K2200/0208

  Carbon · CPC title

• F16L23/18

  the sealing means being rings · CPC title

• F16J15/102

  characterised by material · CPC title