JP5673219B2 - Sphere-shaped sealing body and method for manufacturing the same - Google Patents

Description

  The present invention relates to a ball-shaped seal body suitable for use in a spherical joint of an automobile exhaust pipe and a method for manufacturing the same.

  FIG. 20 shows an example of an exhaust passage of an automobile engine. Exhaust gas generated in each cylinder (not shown) of the engine is collected in an exhaust manifold catalytic converter 600 and is connected to a sub muffler through the exhaust pipe 601 and the exhaust pipe 602. 603. The exhaust gas that has passed through the sub-muffler 603 is further sent to the muffler (silencer) 606 through the exhaust pipe 604 and the exhaust pipe 605, and is released into the atmosphere through the muffler 606.

  Exhaust system members such as the exhaust pipes 601 and 602, 604 and 605, the sub muffler 603, and the muffler 606 are repeatedly subjected to stress due to the roll behavior and vibration of the engine. In particular, in the case of a high-speed engine with high-speed rotation, the stress applied to the exhaust system member is considerably large. Therefore, the exhaust system member may cause fatigue failure, and the vibration of the engine may cause the exhaust system member to resonate and deteriorate the quietness of the passenger compartment. In order to solve such a problem, the connection portion 607 between the exhaust manifold catalytic converter 600 and the exhaust pipe 601 and the connection portion 608 between the exhaust pipe 604 and the exhaust pipe 605 are absorbed by vibrations such as an exhaust pipe spherical joint or a bellows type joint. By movably connecting with the mechanism, the stress repeatedly applied to the exhaust system member due to the roll behavior and vibration of the automobile engine is absorbed, preventing fatigue failure of the exhaust system member and the vibration of the engine resonating the exhaust system member The problem of worsening the quietness in the passenger compartment is also solved.

  Here, an example of the spherical pipe joint as the prior art will be described with reference to FIG.

  In the exhaust pipe spherical joint shown in FIG. 21, a flange 102 is erected on the outer peripheral surface of the upstream exhaust pipe 100 connected to the engine side, leaving the pipe end 101. A spherically shaped seal body 200 having a partially convex spherical surface portion 201 and a cylindrical surface portion 202 connected to the partially convex spherical surface portion 201 is fitted on an outer surface of a cylindrical inner surface 203 that defines a through hole. A ball-shaped seal body 200 is abutted against and seated on the flange 102 at the annular end surface 204 on the radial side, and is disposed opposite to the upstream exhaust pipe 100 and is connected to the muffler side. An enlarged diameter portion 303 integrally including a concave spherical surface portion 301 and a flange portion 302 connected to the concave spherical surface portion 301 is fixed to 300, and an inner surface 304 of the concave spherical surface portion 301 is a spherical belt-like seal body 2. It is in sliding contact with the outer surface 205 of 0 in the partially convex spherical surface portion 201.

  In the exhaust pipe spherical joint, one end is fixed to the flange 102, and the other end is inserted between the flange portion 302 of the enlarged diameter portion 303 and between the pair of bolts 400 and the huge head portion of the bolt 400 and the flange portion 302. A spring force is always applied to the downstream side exhaust pipe 300 in the direction of the upstream side exhaust pipe 100 by the pair of coil springs 500 disposed on the downstream side. The exhaust pipe spherical joint has an outer surface 205 of the partially convex spherical portion 201 of the spherical belt-shaped seal body 200 and the end of the downstream exhaust pipe 300 with respect to relative angular displacement occurring in the upper and downstream exhaust pipes 100 and 300. It is configured to allow this by sliding contact with the inner surface 304 of the concave spherical surface portion 301 of the enlarged diameter portion 303 formed in the portion.

  As a spherical belt-shaped sealing body used for the exhaust pipe spherical joint, there is one described in Patent Document 1, for example. The spherical belt-shaped sealing body described in Patent Document 1 is formed by superposing a reinforcing material and a heat-resistant material made of an expanded graphite sheet from a wire mesh, and then winding it into a cylindrical shape a plurality of times and compressing it in the axial direction. Thus, the spherical belt-like sealing body has a cylindrical inner surface that defines a through-hole at the center, and has a partially convex spherical surface and a cylindrical surface portion continuous with the partially convex spherical surface on the outer surface. And this spherical belt-like sealing body has heat resistance, has good compatibility with the counterpart material, and therefore has an advantage of excellent sealing performance and significantly improved impact strength.

JP 54-76759 A

  However, in the exhaust system of an automobile engine that is used by incorporating this ball-shaped seal body, in cold regions, a snow melting agent as a road surface anti-freezing agent is applied to the road surface and forms a main component that is applied as a snow melting agent. Calcium chloride or sodium chloride dissolves in water, liquefies, adheres to the body part of automobiles as water spray, and generates rust, and chloride attached to the ball-shaped seal promotes the disappearance of graphite at high temperatures. It is known to act as a catalyst.

  That is, the annular portion Q shown in FIG. 21 (corresponding to the cylindrical surface portion 202 of the ball-shaped seal body 200) is directly exposed to the atmosphere, and the portion is in a high-temperature oxidizing atmosphere. Therefore, in the use in an oxidizing atmosphere at a high temperature, when a chloride such as calcium chloride or sodium chloride as a snow melting agent adheres to the annular portion Q, a spherical band shape is combined with the catalytic action of the chloride. There is a problem that oxidation of the expanded graphite forming the sealing body is promoted to disappear, and the sealing performance at the sealing surface between the annular end surface on the large-diameter side of the spherical belt-shaped sealing body and the flange contacting the annular end surface is impaired.

  The present invention has been made in view of the above-mentioned points, and the object of the present invention is to maintain hermeticity even in a salt damage environment atmosphere and a high temperature oxidation atmosphere caused by a snow melting agent sown on the road surface. An object of the present invention is to provide a spherical belt-like seal body that can generate frictional noise and does not generate abnormal noise, and a method for manufacturing the same.

  A spherical belt-like sealing body used for the exhaust pipe joint of the present invention includes a spherical belt-like base body defined by a cylindrical inner surface, a partially convex spherical surface, and large-diameter and small-diameter annular end surfaces of the partially convex spherical surface, An outer layer integrally formed on the partially convex spherical surface of the belt-like substrate, and the spherical belt-like substrate is filled with a reinforcement made of a wire mesh and a mesh of the reinforcement mesh, and mixed with the reinforcement. A heat-resistant material made of expanded graphite containing an oxidation inhibitor that is integrated and compressed, and the outer layer is a heat-resistant material made of expanded graphite containing an oxidation inhibitor, a reinforcement made of a solid lubricant, and a wire mesh The material is mixed and integrated, and the smooth outer surface of the outer layer is a mixture of a surface made of a reinforcing metal mesh and a surface made of a solid lubricant. The annular end surface on the large diameter side and the large diameter side of the outer layer contains an oxidation inhibitor. Cylindrical body consisting of one of the heat-resistant material with the boron carbide and the metal boride consisting Zhang graphite is formed integrally.

  According to the spherical belt-shaped sealing body of the present invention, the cylindrical surface portion of the spherical belt-shaped sealing body that is directly exposed to the atmosphere, that is, the annular end surface on the large diameter side of the partially convex spherical surface of the spherical belt-shaped substrate and the circular surface on the large diameter side of the outer layer. The cylindrical body integrally formed on the end surface is formed of a heat-resistant material made of expanded graphite containing an oxidation inhibitor and at least one of boron carbide and metal boride, and the heat-resistant material is in a salt damage environment atmosphere And having excellent oxidation resistance and heat resistance in a high-temperature oxidizing atmosphere, the oxidation consumption of the heat-resistant material forming the cylindrical body, particularly expanded graphite, is suppressed, and as a result, the end face of the cylindrical body and the end face Leakage of exhaust gas from between the flange portion in contact with the end face is prevented as much as possible.

  In the spherical belt-shaped seal body of the present invention, the oxidation inhibitor may contain phosphate or phosphate and phosphorus pentoxide.

The phosphate is preferably primary lithium phosphate (LiH ₂ PO ₄ ), secondary lithium phosphate (Li ₂ HPO ₄ ), primary calcium phosphate [Ca (H ₂ PO ₄ ) ₂ ], dibasic calcium phosphate (CaHPO). ₄ ), selected from primary aluminum phosphate [Al (H ₂ PO ₄ ) ₃ ], secondary aluminum phosphate [Al ₂ (HPO ₄ ) ₃ ], and this phosphate has a content of 0.1 to 16 mass based on expanded graphite. It is good to contain in the ratio of%.

  Phosphorus pentoxide is contained in particular together with a phosphate to further improve the oxidation inhibiting action on expanded graphite, and the content thereof is 0.05 to 5% by mass in a preferred example.

  In the spherical band-shaped sealing body of the present invention, in a preferable example, the cylindrical body is 5 to 50% by mass, more preferably 10 to 40% by mass, and further preferably 10 to 30% by mass of at least one of boron carbide and metal boride. %contains.

In a preferred example, the metal boride is selected from Group IVa, Group Va and Group VIa of the Periodic Table of Elements. Specifically, titanium boride (TiB), titanium diboride (TiB ₂ ), zirconium diboride (ZrB ₂ ), zirconium twelve boride (ZrB ₁₂ ), hafnium diboride (HfB ₂ ), two Vanadium boride (VB ₂ ), niobium diboride (NbB ₂ ), tantalum diboride (TaB ₂ ), chromium boride (CrB), chromium diboride (CrB ₂ ), molybdenum boride (MoB), two Molybdenum boride (MoB ₂ ), dimolybdenum pentaboride (Mo ₂ B ₅ ), tungsten boride (WB), tungsten diboride (WB ₂ ), ditungsten boride (W ₂ B), dipentaboride At least one may be selected from tungsten (W ₂ B ₅ ).

These boron carbides and metal borides react with oxygen at a high temperature to form boron oxide (B ₂ O ₃ ), which becomes glassy at a temperature of 550 ° C. or more and covers the expanded graphite. It is presumed that the effect of inhibiting oxidation is exhibited.

  The solid lubricant preferably contains 23 to 57% by mass of hexagonal boron nitride, 5 to 15% by mass of alumina hydrate, and 33 to 67% by mass of ethylene tetrafluoride resin.

  The outer layer integrally formed on the partially convex spherical surface of the spherical belt-like substrate serving as the sliding surface with the counterpart material is composed of a heat-resistant material made of expanded graphite containing an oxidation inhibitor, and hexagonal boron nitride 23 to 57 mass%. A solid lubricant composed of 5-15% by mass of alumina hydrate and 33-67% by mass of ethylene tetrafluoride resin, and a reinforcing material composed of a wire mesh are compressed to form a solid lubricant in the mesh of the reinforcing material mesh The heat-resistant material is filled and the solid lubricant and the heat-resistant material and the reinforcing material are mixed and integrated, and the outer surface of the outer layer includes a surface made of a metal mesh of the reinforcing material and a surface made of a solid lubricant. In the spherical belt-shaped sealing body according to the present invention formed on a smooth surface in which the solid lubricant is mixed, the solid lubricant can be prevented from falling off from the outer surface, and as a result, the counterpart material is a solid lubricant and a reinforcing material. Slides on a mixed smooth surface to prevent frictional noise as much as possible. It is possible.

  The spherical inner surface defined by the cylindrical inner surface, the partially convex spherical surface, and the annular end surfaces on the large diameter side and the small diameter side of the partially convex spherical surface, and the partially convex spherical surface of the spherical belt substrate are integrally formed. The manufacturing method of the spherical belt-shaped sealing body according to the present invention that includes an outer layer and is used for an exhaust pipe joint includes (a) a step of preparing an expanded graphite sheet containing an oxidation inhibitor, and (b) a woven metal wire Preparing a wire mesh obtained by knitting or knitting, forming a polymer by superimposing the wire mesh on the expanded graphite sheet, and winding the polymer into a cylindrical shape to obtain a tubular base material; c) preparing another expanded graphite sheet similar to the expanded graphite sheet, coating one surface of the other expanded graphite sheet with an aqueous dispersion of a solid lubricant, and drying to obtain a surface of another expanded graphite sheet Form a coating layer of solid lubricant on And (d) inserting another expanded graphite sheet on which the coating layer is formed between two layers made of another wire mesh obtained by weaving or knitting a fine metal wire, and Supply the inserted wire mesh to the gap between a pair of cylindrical rollers and pressurize it, and fill the mesh of another wire mesh with another expanded graphite sheet and the solid lubricant of the coating layer formed on the surface of the expanded graphite sheet. A step of forming an outer layer forming member exposed by mixing a surface made of another wire mesh and a surface made of a solid lubricant on the surface; and (e) the outer layer forming member on the outer peripheral surface of the cylindrical base material. Winding the coating layer outside to form a pre-cylindrical molded body, and (f) inserting the pre-cylindrical molded body into the outer peripheral surface of the core of the mold and placing the core in the mold; (G) Boron carbide is added to the pulverized powder of the expanded graphite sheet containing the oxidation inhibitor. Preparing a preformed cylindrical body in which at least one of a metal boride and a mixed powder are mixed and compression molded, and (h) at the end of the preformed cylindrical body disposed in the mold, And a step of compressing and molding the pre-formed cylindrical body and the pre-formed cylindrical body placed on the end surface of the pre-cylindrical shaped body in the mold in the core axis. The spherical belt-shaped substrate is a heat-resistant material made of expanded graphite containing a reinforcing material made of a wire mesh and a mesh of the reinforcing material made of the wire mesh and mixed with the reinforcing material and containing a compressed oxidation inhibitor. The outer layer is formed by mixing and integrating a heat-resistant material made of expanded graphite containing an oxidation inhibitor, a solid lubricant, and a reinforcing material made of another wire mesh, and the outer layer has a smooth outer surface. The surface of the reinforcing material made of wire mesh and the surface made of solid lubricant are mixed A heat-resistant material comprising expansion graphitization containing an oxidation inhibitor, boron carbide, and metal on the annular end surface on the large diameter side of the partially convex spherical surface of the spherical base and the annular end surface on the large diameter side of the outer layer. A cylindrical body made of at least one of the borides is integrally formed.

  According to the method for producing a spherical belt-shaped sealing body of the present invention, at least one of boron carbide and a metal boride is blended with a pulverized powder formed by pulverizing a heat-resistant material made of an expanded graphite sheet containing an oxidation inhibitor. Then, the mixed powder mixture is compression molded to produce a preformed cylindrical body, which is placed at the end of the preliminary cylindrical molded body disposed in the mold, and the preformed cylindrical body and the preliminary cylindrical molded body And the cylindrical body can be firmly and integrally formed on the annular end surface on the large diameter side of the partially convex spherical surface of the spherical base and the annular end surface on the large diameter side of the outer layer, And in the cylindrical body formed by compressing this preformed cylindrical body, due to the flexibility and conformability of the expanded graphite, the end surface of the cylindrical body and the flange are in close contact with each other, from the close surface Leakage of exhaust gas is prevented as much as possible.

  According to the present invention, a spherical belt-shaped sealing body includes a spherical inner surface defined by a cylindrical inner surface, a partially convex spherical surface, and annular end surfaces on the large-diameter side and small-diameter side of the partially convex spherical surface, and the spherical belt-shaped substrate. An outer layer integrally formed on the partially convex spherical surface, and integrally formed on the annular end surface on the large diameter side of the partially convex spherical surface of the spherical base and the annular end surface on the large diameter side of the outer layer. The formed cylindrical body is formed of a heat-resistant material made of expanded graphite containing an oxidation inhibitor and at least one of boron carbide and a metal boride, and the heat-resistant material is used in a salt damage environment atmosphere and a high-temperature oxidation atmosphere. Because it has excellent oxidation resistance and heat resistance in use, the oxidation consumption of the expanded graphite, especially the expanded graphite, is suppressed, resulting in the salt damage environment atmosphere and high temperature oxidation atmosphere of the ball-shaped seal body The end face of the cylindrical body even when used below The leakage of exhaust gas from between the flange portion contacting the end face can be prevented as much as possible.

  Further, in the method for producing a spherical belt-shaped sealing body of the present invention, at least one of boron carbide and metal boride is blended and mixed in a pulverized powder produced by pulverizing a heat-resistant material containing an oxidation inhibitor. The preformed cylindrical body formed by compression molding the prepared mixed powder can be firmly integrated over the annular end surface on the large diameter side of the partially convex spherical surface of the spherical base and the annular end surface of the outer layer, The cylindrical body formed by the preformed cylindrical body is in close contact with the flange standing on the outer peripheral surface of the exhaust pipe spherical joint due to the flexibility and conformability of the expanded graphite. Leakage of exhaust gas from the close surface between the flange and the flange is prevented as much as possible.

FIG. 1 is a longitudinal sectional view of a spherical belt-shaped sealing body manufactured in an example of an embodiment of the present invention. FIG. 2 is a partially enlarged cross-sectional view of the spherical belt-like seal body shown in FIG. FIG. 3 is an explanatory view of a method for forming a reinforcing material in the manufacturing process of the ball-shaped seal body of the present invention. FIG. 4 is a perspective view of the heat-resistant material in the manufacturing process of the ball-shaped seal body of the present invention. FIG. 5 is a plan view showing a wire mesh of a reinforcing material. FIG. 6 is a perspective view of the polymer in the manufacturing process of the ball-shaped seal body of the present invention. FIG. 7 is a plan view of the cylindrical base material in the manufacturing process of the ball-shaped seal body of the present invention. FIG. 8 is a longitudinal sectional view of the cylindrical base material shown in FIG. FIG. 9 is a perspective view of the heat-resistant material in the manufacturing process of the ball-shaped seal body of the present invention. FIG. 10 is a cross-sectional view of a heat-resistant material provided with a coating layer of a solid lubricant in the manufacturing process of the ball-shaped seal body of the present invention. FIG. 11 is an explanatory view of a first forming method of the outer layer forming member in the manufacturing process of the ball-shaped seal body of the present invention. FIG. 12 is an explanatory view of a first forming method of the outer layer forming member in the manufacturing process of the ball-shaped seal body of the present invention. FIG. 13 is a longitudinal cross-sectional view of the outer layer forming member obtained by the first forming method in the manufacturing process of the ball-shaped seal body of the present invention. FIG. 14 is an explanatory diagram of a second method of forming the outer layer forming member in the manufacturing process of the spherical belt-shaped sealing body of the present invention. FIG. 15 is an explanatory diagram of a second forming method of the outer layer forming member in the manufacturing process of the spherical belt shaped sealing body of the present invention. FIG. 16 is a plan view of a preliminary cylindrical molded body in the manufacturing process of the ball-shaped seal body of the present invention. FIG. 17 is a cross-sectional view of the preliminary cylindrical body in the manufacturing process of the ball-shaped seal body of the present invention. FIG. 18 is a cross-sectional view showing a state in which the preliminary cylindrical molded body and the preliminary cylindrical body are inserted into the mold in the manufacturing process of the spherical belt-shaped sealing body of the present invention. FIG. 19 shows an exhaust pipe spherical joint incorporating the ball-shaped seal body of the present invention. In FIG. 19, (a) is a left side view and (b) is a longitudinal sectional view. FIG. 20 is an explanatory diagram of an exhaust system of the engine. FIG. 21 shows an exhaust pipe spherical joint incorporating a conventional spherical belt-like seal body. In FIG. 21, (a) is a left side view and (b) is a longitudinal sectional view.

  Next, the present invention and its embodiments will be described in more detail based on preferred embodiments shown in the drawings. In addition, this invention is not limited to these Examples at all.

  The constituent material in the spherical belt-shaped sealing body of the present invention and the manufacturing method of the spherical belt-shaped sealing body will be described.

<About heat-resistant material I and its manufacturing method>
While stirring concentrated sulfuric acid having a concentration of 98%, a 60% aqueous solution of hydrogen peroxide as an oxidant is added to make a reaction solution. The reaction solution is cooled and maintained at a temperature of 10 ° C., and scale-like natural graphite powder having a particle size of 30 to 80 mesh is added to the reaction solution and reacted for 30 minutes. After the reaction, the acid-treated graphite powder is separated by suction filtration, and the washing operation of stirring the acid-treated graphite powder with water and suction filtering is repeated twice to sufficiently remove sulfur from the acid-treated graphite powder. Next, the acid-treated graphite powder from which the sulfuric acid content has been sufficiently removed is dried in a drying furnace to obtain an acid-treated graphite powder.

While stirring the acid-treated graphite powder, a solution obtained by diluting an aqueous solution of 50% concentration of primary aluminum phosphate [Al (H ₂ PO ₄ ) ₃ ] with methanol as a phosphate is mixed with the acid-treated graphite powder in a spray form. Stir uniformly to make a wettable mixture. The wettable mixture is dried for 2 hours in a drying oven maintained at a temperature of 120 ° C. Subsequently, this was heated (expanded) at a temperature of 950 to 1200 ° C. for 1 to 10 seconds to generate decomposition gas, and expanded graphite particles (expansion magnification: 240 to 300) expanded by expanding the graphite layer by the gas pressure. Times). In this expansion treatment step, water in the structural formula is released from the primary aluminum phosphate. The expanded graphite particles are supplied to a double roller apparatus adjusted to a desired roll gap and roll-molded to produce an expanded graphite sheet having a desired thickness. This expanded graphite sheet is used as a heat resistant material I.

The heat-resistant material I produced in this way contains 0.1 to 16% by mass of primary aluminum phosphate in expanded graphite. The expanded graphite containing the phosphate improves the heat resistance of the expanded graphite itself and imparts an oxidation inhibiting action, so that it can be used in a high temperature region exceeding 600 ° C. to 600 ° C., for example. As the phosphate, in addition to the above-mentioned primary aluminum phosphate, secondary lithium phosphate (Li ₂ HPO ₄ ), primary calcium phosphate [Ca (H ₂ PO ₄ ) ₂ ], secondary calcium phosphate (CaHPO ₄ ), Aluminum diphosphate [Al (HPO ₄ ) ₃ ] can be used.

<Heat-resistant material II and production method thereof>
While stirring the acid-treated graphite powder obtained in the same manner as the above-mentioned acid-treated graphite powder, the acid-treated graphite powder was mixed with a first aluminum phosphate aqueous solution having a concentration of 50% as phosphate and orthophosphoric acid (H) having a concentration of 84% as phosphoric acid. ₃ PO ₄ ) A solution obtained by diluting an aqueous solution with methanol is blended in a spray form, and stirred uniformly to prepare a wettable mixture. The wettable mixture is dried for 2 hours in a drying oven maintained at a temperature of 120 ° C. Subsequently, this was heated (expanded) at a temperature of 950 to 1200 ° C. for 1 to 10 seconds to generate decomposition gas, and expanded graphite particles (expansion magnification: 240 to 300) expanded by expanding the graphite layer by the gas pressure. Times). In this expansion treatment step, water in the structural formula of primary aluminum phosphate is eliminated, and orthophosphoric acid generates a dehydration reaction to generate phosphorus pentoxide. The expanded graphite particles are supplied to a double roller apparatus adjusted to a desired roll gap and roll-molded to produce an expanded graphite sheet having a desired thickness. This expanded graphite sheet is used as a heat-resistant material II.

In the heat-resistant material II thus produced, the expanded graphite contains 0.1 to 16% by mass of primary aluminum phosphate and 0.05 to 5% by mass of phosphorus pentoxide. In the expanded graphite containing phosphate and phosphorus pentoxide, the heat resistance of the expanded graphite itself is further improved than that of the heat-resistant material I and has an oxidation inhibiting action. Use in a high temperature region exceeding 600 ° C. to 600 ° C. is possible. As phosphoric acid, in addition to the above orthophosphoric acid, metaphosphoric acid (HPO ₃ ), polyphosphoric acid, and the like can be used.

As the heat resistant materials I and II, a sheet material having a density of about 1.0 to 1.15 Mg / m ³ and a thickness of about 0.3 to 0.6 mm is preferably used.

<About reinforcing material>
Reinforcing materials are austenitic SUS304, SUS310S, SUS316, ferritic SUS430, etc. A woven wire mesh or a braided wire mesh formed by weaving or knitting one or more fine metal wires made of copper-nickel-zinc alloy (white) wire, brass wire, beryllium copper wire used.

  In the fine metal wire forming the wire mesh, a wire diameter of about 0.28 to 0.32 mm is used, and the mesh width of the wire mesh for the ball-shaped substrate formed of the fine metal wire of the wire diameter (braided wire mesh) 5) having a length of about 4 to 6 mm and a width of about 3 to 5 mm is preferably used, and the mesh width of the wire mesh for the outer layer (see FIG. 5) is 2.5 to 3.5 mm. The one having a width of about 1.5 to 2.5 mm is preferably used.

<About solid lubricant>
The solid lubricant is hexagonal boron nitride (hereinafter abbreviated as “h-BN”) 23 to 57% by mass, alumina hydrate 5 to 15% by mass and ethylene tetrafluoride resin (hereinafter abbreviated as “PTFE”). .) Consisting of a lubricating composition containing 33-67% by weight.

  In the production process of solid lubricant, h-BN powder and PTFE powder are dispersed in alumina sol having a hydrogen ion concentration (pH) of 2 to 3 in which alumina hydrate containing acid as a dispersion medium is dispersed. An aqueous dispersion containing a lubricating composition containing 23 to 57% by mass of h-BN powder, 33 to 67% by mass of PTFE powder and 5 to 15% by mass of alumina hydrate, and having a solid content of 30 to 50% by mass Used in the form of a dispersed aqueous dispersion. The h-BN and PTFE forming the aqueous dispersion are preferably as fine powder as possible, and these are preferably used as fine powder having an average particle size of 10 μm or less, more preferably 0.5 μm or less. .

  The acid contained in the water as the dispersion medium of the alumina sol in the aqueous dispersion acts as a peptizer for stabilizing the alumina sol. Examples of the acid include inorganic acids such as hydrochloric acid, nitric acid, sulfuric acid, and amidosulfuric acid, and nitric acid is particularly preferable.

The alumina hydrate forming the alumina sol in the aqueous dispersion is a compound represented by the composition formula Al ₂ O ₃ .nH ₂ O (in the composition formula, 0 <n <3). In the composition formula, n is usually a number exceeding 0 (zero) and less than 3, preferably 0.5 to 2, and more preferably about 0.7 to 1.5. The alumina hydrate, for example, boehmite _{(Al 2} O 3 · _H 2 O) and diaspore _{(Al 2} O 3 · _H 2 O) alumina monohydrate such as (aluminum hydroxide oxide), gibbsite _(Al 2 O ₃ · _3H 2 O) and bayerite _{(Al 2 O 3 · 3H 2} O) alumina trihydrate, such as, such as pseudo-boehmite and the like.

<About pre-formed cylindrical body>
The refractory material I or the refractory material II is pulverized to produce a pulverized powder having a particle size of 200 to 350 μm, and either boron carbide (hereinafter abbreviated as “B ₄ C”) or metal boride is added to the pulverized powder. A mixed powder containing 5 to 50% by mass of B ₄ C and metal boride is prepared by mixing and mixing 5 to 50% by mass. This mixed powder is loaded into a mold having a cylindrical hollow portion and compressed to produce a preformed cylindrical body.

  Here, a compression molded body was prepared using the above mixed powder, and the compression molded body was subjected to oxidation resistance at high temperature and a sodium chloride (hereinafter referred to as “NaCl”) aqueous solution immersion test, and the compression molded body. Were tested for oxidation depletion rate and resistance to NaCl. The test method and test results will be described.

<Preparation of specimen A>
After heat-resistant material I containing 4% by mass of primary aluminum phosphate was pulverized to prepare a pulverized powder having a particle size of 250 to 300 μm, 10% by mass, 20% by mass, 30% by mass, 50% by mass of B ₄ C was added to the pulverized powder. The mixed powder obtained by blending and mixing each mass% was compression molded at a molding pressure of 1.4 ton / cm ² to produce a rectangular shaped body having a side of 30 mm and a thickness of 6 mm.

The specimen made of the specimen A is
Specimen A-1: Molded body comprising ₄ % by mass of primary aluminum phosphate, 10% by mass of B ₄ C, and the remaining expanded graphite,
Specimen A-2: Molded body comprising ₄ % by mass of primary aluminum phosphate, 20% by mass of B ₄ C, and the remaining expanded graphite,
Specimen A-3: Molded body composed of ₄ % by mass of primary aluminum phosphate, 30% by mass of B ₄ C, and the remaining expanded graphite,
Specimen A-4: Molded body comprising ₄ % by mass of primary aluminum phosphate, 50% by mass of B ₄ C, and the remaining expanded graphite,
It is.

<Preparation of specimen B>
The heat-resistant material I containing 4% by mass of primary aluminum phosphate was pulverized to prepare a pulverized powder having a particle size of 250 to 300 μm, and then chromium diboride (hereinafter abbreviated as “CrB ₂ ”) was added to the pulverized powder. wt%, 20 wt%, respectively compounded 30% by weight, a mixed powder obtained by mixing, compression molded at a molding pressure 1.4 tons / cm ^2, one side 30 mm, the molded bodies of rectangular shape with a thickness of 6mm Produced.

The specimen prepared with the above specimen B is
Specimen B-1: Molded body composed of 4% by mass of primary aluminum phosphate, 10% by mass of CrB ₂ , and the remaining expanded graphite,
Specimen B-2: Molded body comprising 4% by mass of primary aluminum phosphate, 20% by mass of CrB ₂ and the remaining expanded graphite,
Specimen B-3: Molded body comprising 4% by mass of primary aluminum phosphate, 30% by mass of CrB ₂ and the remaining expanded graphite,
It is.

<Preparation of specimen C>
After heat-resistant material II containing 8% by mass of primary aluminum phosphate and 1% by mass of phosphorus pentoxide was pulverized to prepare a pulverized powder having a particle size of 250 to 300 μm, 5% by mass of B ₄ C was added to the pulverized powder. wt%, 15 wt%, 20 wt%, 30 wt%, compounded 50% by weight, respectively, the mixed powder obtained by mixing, compression molded at a molding pressure 1.4 tons / cm ^2, one side 30 mm, thickness A 6 mm-long square shaped body was produced.

The specimen made of the specimen C is
Specimen C-1: Molded body comprising 8% by mass of primary aluminum phosphate, 1% by mass of phosphorus pentoxide, 5% by mass of B ₄ C, and the remaining expanded graphite,
Specimen C-2: Molded body composed of 8% by mass of primary aluminum phosphate, 1% by mass of phosphorus pentoxide, 10% by mass of B ₄ C, and the remaining expanded graphite,
Specimen C-3: Molded body composed of 8% by mass of primary aluminum phosphate, 1% by mass of phosphorus pentoxide, 15% by mass of B ₄ C, and the remaining expanded graphite,
Specimen C-4: Molded body comprising 8% by mass of primary aluminum phosphate, 1% by mass of phosphorus pentoxide, 20% by mass of B ₄ C, and the remaining expanded graphite,
Specimen C-5: Molded body composed of 8% by mass of primary aluminum phosphate, 1% by mass of phosphorus pentoxide, 30% by mass of B ₄ C, and the remaining expanded graphite,
Specimen C-6: Molded body comprising 8% by mass of primary aluminum phosphate, 1% by mass of phosphorus pentoxide, 50% by mass of B ₄ C, and the remaining expanded graphite,
It is.

<Preparation of specimen D>
After heat-resistant material II containing 8% by mass of primary aluminum phosphate and 1% by mass of phosphorus pentoxide was pulverized to produce a pulverized powder having a particle size of 250 to 300 μm, 10% by mass and 20% by mass of CrB ₂ were added to the pulverized powder. % And 30% by mass of each mixed powder obtained by mixing and mixing were compression molded at a molding pressure of 1.4 ton / cm ² to produce a rectangular molded body having a side of 30 mm and a thickness of 6 mm.

The specimen made of the specimen D is
Specimen D-1: Molded body comprising 8% by mass of primary aluminum phosphate, 1% by mass of phosphorus pentoxide, 10% by mass of CrB ₂ , and the remaining expanded graphite,
Specimen D-2: Molded body composed of 8% by mass of primary aluminum phosphate, 1% by mass of phosphorus pentoxide, 20% by mass of CrB ₂ , and the remaining expanded graphite,
Specimen D-3: Molded body comprising 8% by mass of primary aluminum phosphate, 1% by mass of phosphorus pentoxide, 30% by mass of CrB ₂ , and the remaining expanded graphite,
It is.

  Next, the specimens A, B, C, and D were tested for (1) oxidation consumption rate of the specimen in the air at 750 ° C. and (2) resistance to NaCl. The results are shown in Table 1.

<Testing method for oxidation consumption rate>
Specimens A, B, C, and D are exposed to the atmosphere maintained at a temperature of 750 ° C. for 15 hours, and the mass of the specimens A, B, C, and D after the test is measured with respect to the mass before the test. The consumption rate was calculated.

<Testing method for resistance to NaCl>
Specimens A-2, B-2, C-2, C-4, and D-2 were immersed for 20 minutes at room temperature (25 ° C.) in a container storing a 3% by mass NaCl aqueous solution, and then each specimen. The sample was put in a crucible, heated, held at a temperature of 600 ° C. for 30 minutes, then cooled and held at room temperature for 10 minutes as one cycle for each specimen after 5 cycles, 10 cycles and 20 cycles. The mass reduction rate (%) was measured.

In Table 1, specimen E-1 is a heat-resistant material made of an expanded graphite sheet made only of expanded graphite, E-2 is heat-resistant I containing 4% by mass of primary aluminum phosphate, and specimen E-3. Is a heat-resistant material II containing 8% by mass of primary aluminum phosphate and 1% by mass of phosphorus pentoxide. Moreover, the oxidation loss rate in Table 1 - is value of (minus) is shown, which is contained in the expanded graphite was B _{4 C} and CrB ₂ is boron oxide reacts with oxygen (B ₂ O ₃ ) To increase the mass.

  From the test results, the molded body consisting of Specimens A, B, C and D shows a low value in the oxidation consumption rate and NaCl resistance at high temperatures, and in comparison with Specimen E, chlorides such as NaCl are present. It turns out that it has the outstanding oxidation resistance and heat resistance in the salt damage environment atmosphere and high temperature atmosphere which act.

  Next, a method for manufacturing a spherical belt-shaped sealing body made of the above-described constituent materials will be described with reference to the drawings.

  (First step) As shown in FIG. 3, the mesh width formed by knitting a thin metal wire having a wire diameter of 0.28 to 0.32 mm in a cylindrical shape is about 4 to 6 mm in length and about 3 to 5 mm in width (see FIG. 3). 5) is passed between the rollers 2 and 3 to produce a band-shaped metal mesh 4 having a predetermined width, and a reinforcing material 5 is prepared by cutting the band-shaped metal mesh 4 into a predetermined length.

(Second Step) As shown in FIG. 4, an expanded graphite sheet 6 for a spherical band substrate having a density of 1.0 to 1.5 Mg / m ³ , preferably 1.0 to 1.2 Mg / m ³ (heat-resistant material) Prepared from one of I and refractory material II).

  (Third Step) As shown in FIG. 6, in order to make the expanded graphite sheet 6 entirely exposed on the annular end surface on the small diameter side of the partially convex spherical surface in the spherical belt-shaped sealing body (see FIG. 1) described later. Further, the expanded graphite sheet 6 slightly protrudes in the width direction from one end edge 7 in the width direction of the reinforcing material 5 which becomes the annular end surface on the small diameter side of the partially convex spherical surface, and the other end in the width direction of the reinforcing material 5. The expanded graphite sheet 6 protrudes in the length direction from one end edge 9 in the length direction of the reinforcing material 5 so that the edge 8 and the expanded graphite sheet 6 match, while the length of the reinforcing material 5 increases. A polymer 12 in which the expanded graphite sheet 6 and the reinforcing material 5 are overlapped with each other so that the end edge 10 and the end edge 11 in the length direction of the expanded graphite sheet 6 corresponding to the end edge 10 coincide with each other is produced. To do.

  (Fourth step) As shown in FIG. 7, the polymer 12 is spirally wound with the expanded graphite sheet 6 inside, and the expanded graphite sheet 6 is wound once so that the expanded graphite sheet 6 is increased once. The cylindrical base material 13 with the expanded graphite sheet 6 exposed is formed on both. In the tubular base material 13, as shown in FIG. 8, the expanded graphite sheet 6 slightly protrudes in the width direction from one end edge 7 of the reinforcing material 5 on one end edge side in the width direction. On the other edge side, it matches the other edge 8 of the reinforcing member 5.

  (Fifth Step) Similar to the expanded graphite sheet 6, but having a width smaller than the width of the reinforcing material 5 and a length enough to wind the cylindrical base material 13 as shown in FIG. A heat-resistant material 14 for the outer layer is separately prepared.

  (Sixth step) Disperse h-BN powder and PTFE powder in alumina sol having a hydrogen ion concentration of 2 to 3 in which alumina hydrate is dispersed and contained in water as a dispersion medium containing nitric acid acting as a peptizer. An aqueous dispersion containing 30 to 50% by mass of a lubricating composition containing 23 to 57% by mass of h-BN, 33 to 67% by mass of PTFE and 1 to 14% by mass of alumina hydrate as a solid content. Prepare an aqueous dispersion.

  (Seventh step) The above-mentioned aqueous dispersion is applied to one surface of the heat-resistant material 14 shown in FIG. 9 by means of brushing, roller coating, spraying, etc., and this is dried and lubricated as shown in FIG. A solid lubricant coating layer 15 made of the composition is formed.

(Eighth process)
<First Method> As shown in FIGS. 11 to 13, a cylindrical braided wire net obtained by continuously knitting a metal thin wire having a wire diameter of 0.28 to 0.32 mm with a knitting machine (not shown). A heat-resistant material 14 provided with a coating layer 15 of solid lubricant is continuously inserted into the reinforcing material 16 for the outer layer (see FIG. 11), and the reinforcing material 16 into which the heat-resistant material 14 is inserted is inserted at its insertion start end. A heat-resistant material 14 and a reinforcing material 16 are supplied to a gap Δ1 between a pair of cylindrical rollers 17 and 18 having a smooth cylindrical outer peripheral surface from the side and pressed in the thickness direction of the heat-resistant material 14 (see FIG. 12). And the outer layer reinforcing material 16 is filled with a heat-resistant material 14 and a solid lubricant coating layer 15 formed on the surface of the heat-resistant material 14, and the outer layer reinforcing material is filled on the surface. The surface 19 made of 16 and the surface 20 made of the solid lubricant of the coating layer 15 are mixedly exposed. Making flat outer forming member 21.

  <Second Method> Separately prepare the reinforcing material 16 for the outer layer made of the band-shaped wire mesh 4 described in the first step, and as shown in FIG. 14, in the reinforcing material 16 for the outer layer made of the band-shaped wire mesh 4, The heat-resistant material 14 provided with the coating layer 15 of the solid lubricant is inserted, and these are supplied to the gap Δ1 between the rollers 22 and 23 and pressed in the thickness direction of the heat-resistant material 14 as shown in FIG. The reinforcing material 16 and the heat-resistant material 14 are integrated, and the outer layer of the heat-resistant material 14 for the outer layer and the coating layer 15 of the solid lubricant formed on the surface of the heat-resistant material 14 are filled in the mesh of the reinforcing material 16 for the outer layer. Then, the flat outer layer forming member 21 in which the surface 19 made of the reinforcing material 16 for the outer layer and the surface 20 made of the solid lubricant of the coating layer 15 are mixed and exposed on one surface is produced.

  In the first and second methods, the gap Δ1 between the pair of cylindrical rollers 17 and 18 and the rollers 22 and 23 is suitably about 0.4 to 0.6 mm.

  (Ninth Step) The outer layer forming member 21 obtained in this way is wound around the outer peripheral surface of the cylindrical base material 13 with the surface 20 made of the solid lubricant facing outside to produce a preliminary cylindrical molded body 24 (FIG. 16). reference).

(Tenth step) A pulverized powder prepared by pulverizing an expanded graphite sheet made of the heat-resistant material I or the heat-resistant material II and adjusting the particle size to 200 to 350 μm is separately prepared, and either B ₄ C or metal boride is added to the pulverized powder. Is mixed and mixed to prepare a mixed powder containing 5 to 50% by mass of either B ₄ C or metal boride. The mixed powder is loaded into a mold (not shown) having a cylindrical hollow portion, and compressed, and as shown in FIG. 17, a cylindrical inner surface 26, a cylindrical outer surface 27, and an annular end surface defining a through hole 25. A preformed cylindrical body 30 provided with 28 and 29 is produced.

  (Eleventh step) A cylindrical wall surface 31, a partially concave spherical wall surface 32 continuous to the cylindrical wall surface 31 and a through hole 33 continuous to the partially concave spherical wall surface 32 are provided on the inner surface, and a stepped core 34 is inserted into the through hole 33. Thus, a mold 37 as shown in FIG. 18 in which a hollow cylindrical portion 35 and a spherical hollow portion 36 connected to the hollow cylindrical portion 35 are formed is prepared, and a stepped core 34 of the mold 37 is reserved. While inserting the cylindrical molded body 24, one annular end surface 28 is brought into contact with the end surface of the preliminary cylindrical molded body 24, and the preformed cylindrical body 30 is inserted into the stepped core 34 through the through hole 25. The preformed cylindrical body 24 and the preformed cylindrical body 30 are arranged in the hollow cylindrical portion 35 and the spherical belt-shaped hollow portion 36 of the mold 37.

The preformed cylindrical molded body 24 and the preformed cylindrical body 30 disposed in the hollow cylindrical portion 35 and the spherical belt-shaped hollow portion 36 of the mold 37 are 98 to 294 N / mm ² (1 to 3 ton / cm ^{2) in the} core axial direction. ² ) compression-molding with a pressure, and having a through-hole 38 at the center as shown in FIGS. 1 and 2, the cylindrical inner surface 39, the partially convex spherical surface 40, the large convex side of the partially convex spherical surface 40, and A spherical base 43 defined by the annular end surfaces 41 and 42 on the small diameter side, an outer layer 44 formed integrally with the partial convex spherical surface 40 of the spherical base 43, and the partial convex spherical surface on one annular end surface 28. The annular end surface 41 on the large-diameter side of the cylindrical surface 40 and the annular end surface 45 of the outer layer 44 are integrally formed, and are connected to the cylindrical inner surface 39 that defines the through-hole 38 of the spherical base 43 and define the through-hole 46. Cylindrical inner surface 47 and outer surface 4 of outer layer 44 A spherical belt-like seal body 52 including a cylindrical outer surface 49 connected to the cylinder 8 and a cylindrical body 51 having an annular end surface 50 on the opposite side of the small-diameter annular end surface 42 is produced.

  By this compression molding, the spherical base 43 is configured such that the expanded graphite sheet 6 for the spherical base and the reinforcing material 5 for the spherical base are compressed and intertwined to have structural integrity. The outer layer 44 is formed by compressing the outer layer heat-resistant material 14, the solid lubricant made of the lubricating composition, and the outer-layer reinforcing material 16 made of the wire mesh so that the solid lubricant and the heat-resistant material are formed in the mesh of the reinforcing material 16. The material 14 is filled and the solid lubricant and heat-resistant material 14 and the reinforcing material 16 are mixed and integrated, and the outer surface 48 of the outer layer 44 includes a surface 53 made of the reinforcing material 16 for the outer layer and the solid lubricant. The cylindrical body 51 is firmly integrated across the annular end surface 41 on the large-diameter side of the partially convex spherical surface 40 and the annular end surface 45 of the outer layer 44. Has been.

  In the fourth step, instead of winding the polymer 12 in a spiral shape with the expanded graphite sheet 6 for the spherical band-shaped substrate inside, the polymer base 12 is wound in a spiral shape with the reinforcing material 5 inside. When the is formed, the ball-shaped seal body 52 in which the reinforcing material 5 made of a wire mesh is exposed on the cylindrical inner surface 39 of the ball-shaped substrate 43 can be manufactured. In the spherical band-shaped seal body 52 in which the reinforcing member 5 is exposed on the cylindrical inner surface 39, the frictional force between the outer peripheral surface of the exhaust pipe on which the spherical band-shaped seal body 52 is disposed and the cylindrical inner surface 39 of the spherical band-shaped seal body 52. As a result, the adhesion force of the ball-shaped seal body 52 to the outer peripheral surface of the exhaust pipe is increased.

  The spherical belt-like seal body 52 is used by being incorporated in the exhaust pipe spherical joint shown in FIG. That is, in the exhaust pipe spherical joint shown in FIG. 19, a flange 102 is erected on the outer peripheral surface of the upstream exhaust pipe 100 connected to the engine side, leaving the pipe end portion 101. The spherical band-shaped sealing body 52 integrally having the cylindrical body 51 is fitted on the cylindrical inner surface 39 defining the through hole 38 and the cylindrical inner surface 47 defining the through hole 46 of the cylindrical body 51, and The annular end surface 50 of the cylindrical body 51 formed integrally over the annular end surface 41 on the radial side and the annular end surface 45 of the outer layer 44 is seated in contact with the flange 102 and is opposed to the upstream exhaust pipe 100. In the downstream exhaust pipe 300, which is arranged in the same manner and connected to the muffler side, a diameter enlarged portion 303 integrally including a concave spherical portion 301 and a flange portion 302 connected to the concave spherical portion 301 is fixed. The inner surface 304 of the concave spherical surface portion 301 is in sliding contact with the smooth surface 55 in which the surface 53 made of the reinforcing material 16 and the surface 54 made of the solid lubricant are mixed in the outer surface 48 of the outer layer 44 of the spherical belt-shaped seal body 52. Has been.

  Next, the present invention will be described in detail based on examples. The present invention is not limited to these examples.

Using a single austenitic stainless steel wire (SUS304) having a wire diameter of 0.28 mm as a thin metal wire, a cylindrical braided wire mesh having a mesh width of about 4 mm in length and about 5 mm in width is produced, and this is formed between a pair of rollers. It was supplied to the gap to form a belt-shaped wire mesh, which was used as a reinforcing material for a spherical belt-shaped substrate. A heat-resistant material I having a density of 1.12 Mg / m ³ and a thickness of 0.38 mm containing 4% by mass of primary aluminum phosphate was used as the heat-resistant material for the spherical band-shaped substrate. A cylindrical base material in which the heat-resistant material I is wound in a spiral shape for one turn, and then a reinforcing material for a sphere-shaped substrate is superimposed on the inner side of the heat-resistant material I, wound in a spiral shape, and the heat-resistant material I is arranged on the outermost periphery. Was made. In this cylindrical base material, one side in the width direction of the heat-resistant material I is substantially flush with the width of the reinforcing material, and the other side in the width direction of the heat-resistant material I is in the width direction of the reinforcing material for the ball-shaped base. Slightly protrudes (protrusions).

  Using one metal thin wire similar to the above, a cylindrical braided wire mesh having a mesh width of about 3.5 mm and a width of about 1.5 mm is produced, and this is passed between a pair of rollers to form a belt-like wire mesh, This was used as a reinforcing material for the outer layer.

  As the heat-resistant material for the outer layer, the same heat-resistant material I as the heat-resistant material I for the spherical belt-shaped substrate was used, and a heat-resistant material I having a width smaller than the width of the belt-shaped wire mesh for the outer layer was separately prepared.

Hydrogen ion concentration (pH) in which boehmite (alumina monohydrate: Al ₂ O ₃ .H ₂ O) is dispersed and contained as alumina hydrate in water as a dispersion medium containing nitric acid acting as a peptizer is 2 An aqueous dispersion in which h-BN powder and PTFE powder are dispersed and contained in this alumina sol, which includes h-BN 41.7% by mass, PTFE 50.0% by mass, and boehmite 8.3% by mass. One surface of the heat-resistant material I for the outer layer containing an aqueous dispersion (h-BN 20.8% by mass, PTFE 25.0% by mass and boehmite 4.2% by mass) containing 50% by mass of the lubricating composition as a solid content The solid lubricant coating layer (h-BN 41.7% by mass, PTFE 50.0% by mass and boehmite 8) comprising the above-mentioned lubricating composition by roller coating and drying. 3 wt%) was formed.

  The heat-resistant material I provided with the coating layer of the solid lubricant is inserted into a belt-like wire mesh that is a reinforcing material for the outer layer, and these are integrated by passing between a pair of rollers. I and a solid lubricant coating layer formed on the surface of the heat-resistant material I are filled to form a flat outer layer in which a surface made of a reinforcing material and a surface made of a solid lubricant are mixedly exposed. A member was prepared.

  The outer layer forming member was wound around the outer peripheral surface of the cylindrical base material with the surface made of a solid lubricant facing outward to prepare a preliminary cylindrical molded body. This preliminary cylindrical molded body was inserted into the stepped core of the mold shown in FIG. 18, and the preliminary cylindrical molded body was disposed in the hollow portion of the mold.

A heat-resistant material I containing 4% by mass of primary aluminum phosphate similar to the heat-resistant material I for the spherical belt-shaped substrate and the outer layer is prepared, the heat-resistant material I is pulverized, and this is put into a mixer and stirred and mixed. A pulverized powder of heat-resistant material I having a particle size adjusted to 250 to 350 μm was prepared. This ground powder, B 4 _C powder were blended by mixing 20 mass%, aluminum primary phosphate 4 wt%, to prepare a mixed powder consisting of B 4 _C20 wt% and expanded graphite. This mixed powder was loaded into a cylindrical hollow portion of a mold and compression molded to prepare a preformed cylindrical body having a cylindrical inner surface and a cylindrical outer surface defining the through-holes and annular end surfaces at both ends.

  The preformed cylindrical body thus obtained was placed in the hollow portion of the mold such that one annular end face was brought into contact with the end of the preformed cylindrical body placed in the hollow portion of the mold.

A pre-cylindrical molded body and a pre-formed cylindrical body arranged in the hollow portion of the mold are compression-molded at a pressure of 294 N / mm ^{2 in} the core axial direction, and a cylindrical inner surface defining a through hole in the central portion and a partially convex spherical shape A spherical band-shaped substrate defined by the surface and the annular end surfaces on the large-diameter side and the small-diameter side of the partially convex spherical surface, an outer layer integrally formed on the partially convex spherical surface of the spherical band-shaped substrate, and the partially convex spherical surface A spherical belt-like seal body provided with an annular end surface on the large diameter side of the cylindrical surface and a cylindrical body integrally formed across the annular end surface of the outer layer was obtained.

By this compression molding, the spherical belt-shaped substrate is configured such that the heat-resistant material for the spherical belt-shaped substrate and the reinforcing material for the spherical belt-shaped substrate made of a wire mesh are compressed and entangled with each other to have structural integrity. A reinforcing material for a spherical belt-shaped substrate made of a wire mesh, and a spherical belt-shaped substrate made of expanded graphite containing primary aluminum phosphate that is packed together and integrated with the reinforcing material. A solid lubricant comprising an outer layer heat-resistant material, a lubricant composition containing 41.7% by mass of h-BN, 50.0% by mass of PTFE, and 8.3% by mass of boehmite. And the reinforcing material for the outer layer made of the wire mesh is compressed and the mesh of the reinforcing material mesh is filled with the solid lubricant and the heat-resistant material, and the solid lubricant, the heat-resistant material and the reinforcing material are mixed and integrated. The outer surface of the outer layer is a reinforcing material. And a surface made of a solid lubricant is formed into a smooth surface, and the first phosphoric acid is formed over the large-diameter annular end surface of the partially convex spherical surface of the spherical base and the annular end surface of the outer layer. A cylindrical body composed of ₄ % by mass of aluminum, 20% by mass of B ₄ C, and expanded graphite is firmly and integrally formed.

  A cylindrical base material similar to that of Example 1 was prepared. In this cylindrical base material, one side in the width direction of the heat-resistant material I is substantially flush with the width of the reinforcing material, and the other side in the width direction of the heat-resistant material I is in the width direction of the reinforcing material for the ball-shaped base. Slightly protrudes (protrusions).

  Using one thin metal wire similar to that in Example 1, a cylindrical braided net having a mesh width of about 3.5 mm and a width of about 1.5 mm is produced, and this is passed between a pair of rollers to form a belt-like shape. A wire mesh was used as a reinforcing material for the outer layer.

  As the heat-resistant material for the outer layer, the same heat-resistant material I as in Example 1 was used, and a heat-resistant material I having a width smaller than the width of the belt-shaped wire mesh was separately prepared.

  An aqueous dispersion in which the same alumina sol as in Example 1 was prepared, and h-BN powder and PTFE powder were dispersed and contained in the alumina sol. An aqueous dispersion (h-BN 27.3% by mass, PTFE 17.3% by mass and boehmite 5.4% by mass) containing 50% by mass of a lubricating composition containing 9% by mass as a solid content is heat-resistant for the outer layer. One surface of I was coated with a roller and dried to form a coating layer (h-BN 54.6% by mass, PTFE 34.5% by mass and boehmite 10.9% by mass) made of the lubricating composition. .

  The heat-resistant material I provided with the coating layer of the solid lubricant is inserted into a belt-like wire mesh that is a reinforcing material for the outer layer, and these are integrated by passing between a pair of rollers. And a coating layer of a solid lubricant formed on the surface of the heat-resistant material I, and a flat outer layer forming member in which a surface made of a reinforcing material and a surface made of a solid lubricant are mixed and exposed on the surface Was made.

  Hereinafter, a preliminary cylindrical molded body is produced in the same manner as in Example 1, and this preliminary cylindrical molded body is inserted into the stepped core of the mold shown in FIG. 18, and the preliminary cylindrical molded body is inserted into the hollow portion of the mold. Was located.

In the same manner as in Example 1, a pulverized powder of heat-resistant material I having a particle size adjusted to 250 to 350 μm was prepared, and 20% by mass of CrB ₂ powder was mixed with this pulverized powder and mixed to obtain 4 mass of primary aluminum phosphate. %, CrB ₂ 20% by mass and expanded graphite were produced. This mixed powder was loaded into a cylindrical hollow portion of a mold and compression molded to prepare a preformed cylindrical body having a cylindrical inner surface and a cylindrical outer surface defining the through-holes and annular end surfaces at both ends.

  Hereinafter, in the same manner as in the first embodiment, a spherical belt shape defined by a cylindrical inner surface defining a through hole in the central portion, a partially convex spherical surface, and a large-diameter side and a small-diameter annular end surface of the partially convex spherical surface. A base, an outer layer integrally formed on the partially convex spherical surface of the spherical base, and a cylindrical shape integrally formed on the annular end surface on the large diameter side of the partially convex spherical surface and the annular end surface of the outer layer A spherical belt-like seal body provided with a body was obtained.

By this compression molding, the spherical belt-shaped substrate is configured such that the heat-resistant material for the spherical belt-shaped substrate and the reinforcing material for the spherical belt-shaped substrate made of a wire mesh are compressed and entangled with each other to have structural integrity. A reinforcing material for a spherical belt-shaped substrate made of a wire mesh, and a spherical belt-shaped substrate made of expanded graphite containing primary aluminum phosphate that is packed together and integrated with the reinforcing material. The outer layer has a heat-resistant material for the outer layer, a solid lubricant made of a lubricating composition containing 54.6% by mass of h-BN, 34.5% by mass of PTFE, and 10.9% by mass of boehmite. And the reinforcing material for the outer layer made of the wire mesh is compressed and the mesh of the reinforcing material mesh is filled with the solid lubricant and the heat-resistant material, and the solid lubricant, the heat-resistant material and the reinforcing material are mixed and integrated. The outer surface of the outer layer is a reinforcing material. And a surface made of a solid lubricant are formed in a smooth surface, and the first surface extends from the annular end surface on the large diameter side of the partially convex spherical surface of the spherical base and the annular end surface of the outer layer. A cylindrical body made of 4% by mass of aluminum phosphate, 20% by mass of CrB ₂ and expanded graphite is firmly and integrally formed.

The same reinforcing material for the ball-shaped substrate as in Example 1 was used. A heat-resistant material II having a density of 1.12 Mg / m ³ and a thickness of 0.38 mm containing 8% by mass of primary aluminum phosphate and 1% by mass of phosphorus pentoxide was used as the heat-resistant material for the spherical band-shaped substrate. A cylindrical base material in which the heat-resistant material II is wound in a spiral manner for one round, and then a reinforcing material for a spherical belt-like substrate is superimposed on the inner side of the heat-resistant material II and wound in a spiral shape to place the heat-resistant material II on the outermost periphery. Was made. In this cylindrical base material, one side in the width direction of the heat-resistant material II is substantially flush with the width of the reinforcing material, and the other side in the width direction of the heat-resistant material II is in the width direction of the reinforcing material for the ball-shaped base. Slightly protrudes (protrusions).

  Using one thin metal wire similar to that in Example 1, a cylindrical braided net having a mesh width of about 3.5 mm and a width of about 1.5 mm is produced, and this is passed between a pair of rollers to form a belt-like shape. A wire mesh was used as a reinforcing material for the outer layer.

  As the expanded graphite sheet for the outer layer, a heat resistant material II similar to the heat resistant material II for the spherical belt-shaped substrate was used, and a heat resistant material II having a width smaller than the width of the belt metal mesh for the outer layer was separately prepared.

  An aqueous dispersion in which the same alumina sol as in Example 1 was prepared, and h-BN powder and PTFE powder were dispersed and contained in the alumina sol, comprising 30.0% by weight of h-BN, 60.0% by weight of PTFE, and 15% boehmite. An aqueous dispersion (h-BN 15.0% by mass, PTFE 30.0% by mass and boehmite 5.0% by mass) containing 50% by mass of a lubricating composition containing 0% by mass as a solid content is a heat-resistant material for the outer layer. One surface of II was coated with a roller and dried to form a coating layer (h-BN 30.0% by mass, PTFE 60.0% by mass and boehmite 10.0% by mass) made of the lubricating composition. .

  Thereafter, an outer layer forming member is produced in the same manner as in Example 1, and the outer layer forming member is wound around the outer peripheral surface of the cylindrical base material with the surface made of a solid lubricant on the outer side. Was made. This preliminary cylindrical molded body was inserted into the stepped core of the mold shown in FIG. 18, and the preliminary cylindrical molded body was disposed in the hollow portion of the mold.

A heat-resistant material II similar to the heat-resistant material II for the sphere-shaped substrate and the outer layer is prepared, the heat-resistant material II is pulverized, this is put into a mixer and mixed by stirring, and the particle size is adjusted to 250 to 350 μm. A pulverized powder of Material II was prepared. This ground powder, B 4 _C powder were blended by mixing 20 mass%, aluminum primary phosphate 8 wt%, phosphorus pentoxide 1 mass%, to prepare a mixed powder consisting of B 4 _C20 wt% and expanded graphite. This mixed powder was loaded into a cylindrical hollow portion of a mold and compression molded to prepare a preformed cylindrical body having a cylindrical inner surface and a cylindrical outer surface defining the through-holes and annular end surfaces at both ends.

  Hereinafter, in the same manner as in the first embodiment, a spherical belt shape defined by a cylindrical inner surface defining a through hole in the central portion, a partially convex spherical surface, and a large-diameter side and a small-diameter annular end surface of the partially convex spherical surface. A base, an outer layer integrally formed on the partially convex spherical surface of the spherical base, and a cylindrical shape integrally formed on the annular end surface on the large diameter side of the partially convex spherical surface and the annular end surface of the outer layer A spherical belt-like seal body provided with a body was obtained.

By this compression molding, the spherical belt-shaped substrate is configured such that the heat-resistant material for the spherical belt-shaped substrate and the reinforcing material for the spherical belt-shaped substrate made of a wire mesh are compressed and entangled with each other to have structural integrity. A reinforcing material for a ball-shaped substrate made of a wire mesh, and expanded graphite containing primary aluminum phosphate and phosphorus pentoxide filled with the reinforcement mesh wire mesh and mixed and integrated with the reinforcing material. The outer layer is made of expanded graphite containing primary aluminum phosphate and phosphorus pentoxide, 30.0% by mass of h-BN, and PTFE 60.0. A solid lubricant made of a lubricating composition containing 10% by weight and 10.0% by weight of boehmite and a reinforcing material for an outer layer made of a wire mesh are compressed, and the wire mesh of the reinforcing material is filled with the solid lubricant and the heat-resistant material. Solid lubrication And the heat-resistant material and the reinforcing material are mixed and integrated, and the outer surface of the outer layer is formed in a smooth surface in which the surface made of the reinforcing material and the surface made of the solid lubricant are mixed, A cylindrical body made of 8% by mass of first aluminum phosphate, 1% by mass of phosphorus pentoxide, 20% by mass of B ₄ C and expanded graphite over the annular end surface on the large diameter side of the partially convex spherical surface of the substrate and the annular end surface of the outer layer. Are firmly and integrally formed.

  In the same manner as in Example 3, a cylindrical base material was produced. One side in the width direction of the heat-resistant material II is substantially flush with the width of the reinforcing material, and the other side in the width direction of the heat-resistant material II slightly protrudes (protrudes) in the width direction of the reinforcing material for the ball-shaped base. Yes.

  Using one thin metal wire similar to that in Example 1, a cylindrical braided net having a mesh width of about 3.5 mm and a width of about 1.5 mm is produced, and this is passed between a pair of rollers to form a belt-like shape. A wire mesh was used as a reinforcing material for the outer layer.

  As the expanded graphite sheet for the outer layer, a heat resistant material II similar to the heat resistant material II for the spherical belt-shaped substrate was used, and a heat resistant material II having a width smaller than the width of the belt metal mesh for the outer layer was separately prepared.

  An aqueous dispersion in which the same alumina sol as in Example 1 was prepared, and h-BN powder and PTFE powder were dispersed and contained in the alumina sol, comprising h-BN 45.0 mass%, PTFE 45.0 mass%, and boehmite 10. An aqueous dispersion (h-BN 22.5% by mass, PTFE 22.5% by mass and boehmite 5.0% by mass) containing 50% by mass of a lubricating composition containing 0% by mass as a solid content is a heat-resistant material for the outer layer. One surface of II was coated with a roller and dried to form a coating layer (h-BN 45.0% by mass, PTFE 45.0% by mass and boehmite 10.0% by mass) made of the lubricating composition. .

  Thereafter, an outer layer forming member is produced in the same manner as in Example 1, and the outer layer forming member is wound around the outer peripheral surface of the cylindrical base material with the surface made of a solid lubricant on the outer side. Was made. This preliminary cylindrical molded body was inserted into the stepped core of the mold shown in FIG. 18, and the preliminary cylindrical molded body was positioned in the hollow portion of the mold.

In the same manner as in Example 3, a pulverized powder of heat-resistant material II having a particle size adjusted to 250 to 350 μm was prepared, and 20% by mass of CrB ₂ powder was mixed with this pulverized powder and mixed to obtain 8 mass of primary aluminum phosphate. %, Phosphorous pentoxide 1% by mass, CrB ₂ 20% by mass and expanded graphite, and the mixed powder is loaded into a cylindrical hollow part of a mold and compression-molded to define a through-hole. A preformed cylindrical body having an inner surface, a cylindrical outer surface, and annular end surfaces at both ends was produced.

  Hereinafter, in the same manner as in the first embodiment, a spherical belt shape defined by a cylindrical inner surface defining a through hole in the central portion, a partially convex spherical surface, and a large-diameter side and a small-diameter annular end surface of the partially convex spherical surface. A base, an outer layer integrally formed on the partially convex spherical surface of the spherical base, and a cylindrical shape integrally formed on the annular end surface on the large diameter side of the partially convex spherical surface and the annular end surface of the outer layer A spherical belt-like seal body provided with a body was obtained.

By this compression molding, the spherical belt-shaped substrate is configured such that the heat-resistant material for the spherical belt-shaped substrate and the reinforcing material for the spherical belt-shaped substrate made of a wire mesh are compressed and entangled with each other to have structural integrity. A reinforcing material for a ball-shaped substrate made of a wire mesh, and expanded graphite containing primary aluminum phosphate and phosphorus pentoxide filled with the reinforcement mesh wire mesh and mixed and integrated with the reinforcing material. The outer layer is made of expanded graphite containing primary aluminum phosphate and phosphorus pentoxide, 45.0% by mass of h-BN and PTFE 45.0. A solid lubricant made of a lubricating composition containing 10% by weight and 10.0% by weight of boehmite and a reinforcing material for an outer layer made of a wire mesh are compressed, and the wire mesh of the reinforcing material is filled with the solid lubricant and the heat-resistant material. Solid lubrication And the heat-resistant material and the reinforcing material are mixed and integrated, and the outer surface of the outer layer is formed in a smooth surface in which the surface made of the reinforcing material and the surface made of the solid lubricant are mixed, A cylindrical body composed of 8% by mass of primary aluminum phosphate, 1% by mass of phosphorus pentoxide, 20% by mass of CrB ₂ and expanded graphite over the annular end surface on the large diameter side of the partially convex spherical surface of the substrate and the annular end surface of the outer layer. Are firmly and integrally formed.

  Next, the ball-shaped seal body obtained in Example 1 to Example 4 described above was incorporated into the exhaust pipe spherical joint shown in FIG. 19 and tested for the presence of abnormal frictional noise and the amount of gas leakage (l / min). The results will be explained.

<Test conditions for presence or absence of abnormal frictional noise>
Pressing force by a coil spring (spring set force): 590N
Oscillation angle: ± 4 °
Excitation frequency: 12Hz
Temperature (outer surface temperature of concave spherical surface portion 301 shown in FIG. 19): room temperature (25 ° C.) to 500 ° C.
Number of tests: 1 million cycles Counterpart material (material of the enlarged diameter portion 303 shown in FIG. 19): SUS304

<Test method>
After performing 45,000 swings of ± 4 ° with a vibration frequency of 12 Hz at room temperature (25 ° C), the ambient temperature was raised to 500 ° C while continuing the swinging motion. When the temperature reaches 500 ° C., 115,000 swings are performed, and the ambient temperature is lowered to room temperature while continuing the swings. The total number of oscillations of 250,000 times, that is, the number of times of swaying while cooling is 45,000 times, is 4 cycles.

The evaluation of the presence or absence of occurrence of abnormal frictional noise is performed by (1) 250,000 swings, (2) 500,000 swings, (3) 750,000 swings, and (4) 100 swings. At the time of 10,000 times, it carried out as follows.
<Determination level of frictional noise>
Evaluation symbol A: No frictional noise is generated.
Evaluation symbol B: An abnormal frictional sound can be heard with the ear close to the test piece.
Evaluation symbol C: At a fixed position (position 1.5 m away from the test piece)
In general, it is difficult to distinguish, but it can be identified as an abnormal frictional sound by the person in charge of the test.
Evaluation symbol D: One that can be identified as an abnormal frictional sound (unpleasant sound) by anyone at a fixed position.

<Test conditions and test method for gas leakage>
<Test conditions>
Pressing force by a coil spring (spring set force): 980N
Excitation angle: ± 2.5 °
Excitation frequency (oscillation speed): 5Hz
Temperature (outer surface temperature of concave spherical surface portion 301 shown in FIG. 19): room temperature (25 ° C.) to 500 ° C.
Number of swings: 1 million times Counterpart material (material of the enlarged diameter portion 303 shown in FIG. 19): SUS304

<Test method>
At room temperature (25 ° C), the temperature is raised to 500 ° C while continuing the oscillating motion of ± 2.5 ° at an excitation frequency of 5 Hz, and the oscillating motion is continued while maintaining the temperature. The amount of gas leakage when the number of times reached 1 million was measured.

<Measurement method of gas leakage>
The opening of one upstream exhaust pipe 100 of the exhaust pipe spherical joint shown in FIG. 19 is closed, and dry air is supplied from the other downstream exhaust pipe 300 side at a pressure of 0.049 MPa (0.5 kgf / cm ² ). The joint portion (the sliding contact portion between the surface 48 of the spherical belt-like seal body 52 and the diameter-enlarging portion 303, the fitting portion between the cylindrical inner surface 39 of the spherical belt-like seal body 52 and the pipe end portion 101 of the upstream side exhaust pipe 100) And the amount of gas leakage from the annular end surface 50 and the flange 102 erected on the upstream side exhaust pipe 100) using a flow meter, (1) initial test (before test start), (2) rocking The measurement was performed 4 times after 250,000 times, (3) after 500,000 times of rocking and (4) after 1 million times of rocking.

  Table 2 shows the test results.

From the above test results, a ball-shaped substrate having a through-hole at the center and defined by the cylindrical inner surface, the partially convex spherical surface, and the large-diameter and small-diameter annular end surfaces of the partially convex spherical surface, An outer layer integrally formed on the partially convex spherical surface, an annular end surface on the large-diameter side of the partially convex spherical surface, and a phosphate or phosphate and phosphorus pentoxide formed integrally on the annular end surface of the outer layer In addition, the spherical belt-shaped sealing body comprising Example 1, Example 2, Example 3 or Example 4 provided with a tubular body made of expanded graphite containing B ₄ C or metal boride (CrB ₂ ) is exhausted. Since the cylindrical body exposed to a high-temperature oxidizing atmosphere in the state incorporated in the tube spherical joint has oxidation resistance and heat resistance, the oxidation consumption of the expanded graphite in the cylindrical body is suppressed, As a result, the annular end surface of the cylindrical body and the flat plate in contact with the annular end surface Leakage of exhaust gas from between the outer surface and the outer surface of the ball-shaped seal body is prevented as much as possible, and the outer surface of the outer layer of these ball-shaped seal bodies is a smooth surface in which a surface made of a reinforcing material for the outer layer and a surface made of a solid lubricant are mixed. Since the outer surface of the outer layer is formed on a smooth surface, smooth sliding with the mating member is performed without generating frictional noise in sliding friction with the mating material.

  As described above, in the state of being incorporated in the exhaust pipe spherical joint, the ball-shaped seal body according to the present invention is exposed to a salt damage environment atmosphere and a high-temperature oxidizing atmosphere in which chlorides such as NaCl and calcium chloride act. Since the shaped body has excellent oxidation resistance and heat resistance in a salt-damaged environment atmosphere and a high-temperature oxidizing atmosphere, the oxidation consumption of the expanded graphite in the tubular body is suppressed, and as a result, the sphere of the present invention According to the belt-shaped sealing body, it is possible to prevent leakage of exhaust gas from the end surface of the cylindrical body and the flange portion in contact with the end surface as much as possible, and the outer surface of the outer layer of the spherical belt-shaped sealing body is used for the outer layer. Since the surface made of the reinforcing material and the surface made of the solid lubricant are formed in a smooth surface, the outer surface of the outer layer is smooth without causing frictional noise in sliding friction with the mating material. Sliding is done .

  Further, in the method for producing a spherical belt-shaped sealing body of the present invention, at least one of boron carbide and a metal boride is blended in a pulverized powder produced by pulverizing an expanded graphite sheet made of a heat-resistant material containing an oxidation inhibitor, Since the mixed powder produced by mixing is compression-molded into a cylindrical shape in advance to form a preformed cylindrical body, the preformed cylindrical body is formed into an annular end surface on the large diameter side of the partially convex spherical surface of the spherical belt-shaped substrate. And it can integrate firmly as a cylindrical body over the annular end surface of an outer layer.

DESCRIPTION OF SYMBOLS 5 Reinforcement material 6 Expanded graphite sheet 12 Polymer 13 Tubular base material 21 Outer layer forming member 24 Preliminary cylindrical molded body 30 Preliminary molded cylindrical body 37 Mold 39 Cylindrical inner surface 40 Partial convex spherical surface 41 Large-diameter side annular end surface 42 Annular end face on the small diameter side 43 Spherical belt substrate 44 Outer layer 51 Tubular body 52 Spherical belt seal body

Claims (19)

  A spherical base defined by a cylindrical inner surface, a partially convex spherical surface, and annular end surfaces on the large diameter side and the small diameter side of the partially convex spherical surface, and the partially convex spherical surface of the spherical belt base body are integrally formed. A spherical belt-like sealing body that is provided with an outer layer and is used for an exhaust pipe joint. The spherical belt-shaped base body is filled with a reinforcing material made of a wire mesh and a mesh of the reinforcing material wire mesh, and mixed with this reinforcing material. And a heat-resistant material made of expanded graphite containing a compressed oxidation inhibitor, and the outer layer is a heat-resistant material made of expanded graphite containing an oxidation inhibitor, a reinforcing material made of a solid lubricant and a wire mesh And the smooth outer surface of the outer layer is a mixture of a surface made of a reinforcing material wire mesh and a surface made of a solid lubricant, and the surface of the partially convex spherical surface of the spherical belt-shaped substrate is mixed. The annular end surface on the large diameter side and the annular end surface on the large diameter side of the outer layer Spherical annular seal member which tubular member comprising at least one of the heat-resistant material with the boron carbide and the metal boride consisting of expanded graphite containing inhibitor is characterized in that it is formed integrally.   The ball-shaped seal body according to claim 1, wherein the oxidation inhibitor contains a phosphate. Phosphate includes primary lithium phosphate (LiH ₂ PO ₄ ), secondary lithium phosphate (Li ₂ HPO ₄ ), primary calcium phosphate [Ca (H ₂ PO ₄ ) ₂ ], dibasic calcium phosphate (CaHPO ₄ ), The spherical belt-shaped sealing body according to claim 2, wherein the sealing body is selected from primary aluminum phosphate [Al (H ₂ PO ₄ ) ₃ ] and secondary aluminum phosphate [Al ₂ (HPO ₄ ) ₃ ].   The spherical band-shaped sealing body according to any one of claims 1 to 3, wherein the oxidation inhibitor contains 0.1 to 16% by mass of a phosphate.   The spherical band-shaped sealing body according to any one of claims 1 to 4, wherein the oxidation inhibitor contains 0.05 to 5 mass% of phosphorus pentoxide.   The spherical body seal body according to any one of claims 1 to 5, wherein the cylindrical body contains 5 to 50% by mass of at least one of boron carbide and metal boride.   The spherical band-shaped sealing body according to any one of claims 1 to 6, wherein the metal boride is selected from Group IVa, Group Va and Group VIa of the Periodic Table of Elements. The metal borides are titanium boride (TiB), titanium diboride (TiB ₂ ), zirconium diboride (ZrB ₂ ), zirconium dodecaride (ZrB ₁₂ ), hafnium diboride (HfB ₂ ), two Vanadium boride (VB ₂ ), niobium diboride (NbB ₂ ), tantalum diboride (TaB ₂ ), chromium boride (CrB), chromium diboride (CrB ₂ ), molybdenum boride (MoB), two Molybdenum boride (MoB ₂ ), dimolybdenum pentaboride (Mo ₂ B ₅ ), tungsten boride (WB), tungsten diboride (WB ₂ ), ditungsten boride (W ₂ B), dipentaboride The spherical belt-shaped sealing body according to any one of claims 1 to 7, wherein at least one selected from tungsten (W ₂ B ₅ ).   The solid lubricant contains 23 to 57% by mass of hexagonal boron nitride, 5 to 15% by mass of alumina hydrate, and 33 to 67% by mass of ethylene tetrafluoride resin. 2. A ball-shaped seal body according to 1. The spherical inner surface defined by the cylindrical inner surface, the partially convex spherical surface, and the annular end surfaces on the large diameter side and the small diameter side of the partially convex spherical surface, and the partially convex spherical surface of the spherical belt substrate are integrally formed. An outer layer and a method for manufacturing a spherical belt-shaped seal body used for an exhaust pipe joint,
(A) preparing an expanded graphite sheet containing an oxidation inhibitor;
(B) A wire mesh obtained by weaving or knitting a fine metal wire is prepared, a polymer is formed by superimposing the wire mesh on the expanded graphite sheet, and then the polymer is wound into a cylindrical shape to form a cylindrical base. Obtaining a material;
(C) preparing another expanded graphite sheet similar to the expanded graphite sheet, coating one surface of the other expanded graphite sheet with an aqueous dispersion of a solid lubricant, and drying to obtain another expanded graphite sheet. Forming a coating layer of a solid lubricant on the surface;
(D) Another expanded graphite sheet on which the coating layer is formed is inserted between two layers made of another wire mesh obtained by weaving or knitting fine metal wires, and the other expanded graphite sheet is inserted. Is supplied to the gap between the pair of cylindrical rollers and pressurized, filled with another expanded graphite sheet and a solid lubricant of the coating layer formed on the surface of the expanded graphite sheet, A step of forming an outer layer forming member exposed by mixing a surface made of another wire mesh and a surface made of a solid lubricant,
(E) winding the outer layer forming member on the outer peripheral surface of the cylindrical base material with the covering layer facing outside to form a preliminary cylindrical molded body;
(F) inserting the preliminary cylindrical molded body into a core outer peripheral surface of a mold and disposing the core in the mold;
(G) A step of preparing a preformed cylindrical body formed by compressing and molding a mixed powder obtained by blending at least one of boron carbide and a metal boride into a pulverized powder of an expanded graphite sheet containing an oxidation inhibitor. When,
(H) The preformed cylindrical body is placed on the end of the preliminary cylindrical molded body disposed in the mold, and placed on the preliminary cylindrical molded body and the end surface of the preliminary cylindrical molded body in the mold. A step of compressing and molding the preformed cylindrical body in the core axial direction;
And a spherical band-shaped substrate is filled with a reinforcing material made of a wire mesh, and expanded graphite containing a compressed oxidation inhibitor that is mixed and integrated with the reinforcing material. The outer layer comprises a heat-resistant material made of expanded graphite containing an oxidation inhibitor, a solid lubricant, and a reinforcing material made of another wire mesh. The outer surface is a mixture of a surface made of a reinforcing material wire mesh and a surface made of a solid lubricant. A spherical belt-shaped seal characterized in that a cylindrical body made of a heat-resistant material made of expanded graphite containing an oxidation inhibitor and at least one of boron carbide and metal boride is integrally formed on the annular end face. Body manufacturing method.   The method for producing a spherical belt-shaped sealing body according to claim 10, wherein the oxidation inhibitor contains a phosphate. Phosphate includes primary lithium phosphate (LiH ₂ PO ₄ ), secondary lithium phosphate (Li ₂ HPO ₄ ), primary calcium phosphate [Ca (H ₂ PO ₄ ) ₂ ], dibasic calcium phosphate (CaHPO ₄ ), aluminum primary phosphate _[Al (H 2 _{PO 4) 3]} the method of manufacturing a spherical annular seal member according to claim 11 which is selected from a second aluminum phosphate _[Al 2 _{(HPO 4) 3].}   The method for producing a spherical belt-shaped sealing body according to any one of claims 10 to 12, wherein the oxidation inhibitor contains 0.1 to 16% by mass of a phosphate.   The method for producing a spherical belt-shaped sealing body according to any one of claims 10 to 13, wherein the oxidation inhibitor contains 0.05 to 5% by mass of phosphoric acid. The phosphoric acid is a chain condensed phosphoric acid or trimetaphosphoric acid composed of orthophosphoric acid (H ₃ PO ₄ ), metaphosphoric acid (HPO ₃ ), pyrophosphoric acid (H ₄ P ₂ O ₇ ), tripolyphosphoric acid (H ₅ P ₈ O ₁₀ ), The method for producing a spherical belt-shaped sealing body according to claim 14, which is selected from cyclic condensed phosphoric acid composed of tetrametaphosphoric acid.   The method for producing a spherical belt-shaped sealing body according to any one of claims 10 to 15, wherein the preformed cylindrical body contains 5 to 50% by mass of at least one of boron carbide and a metal boride.   The metal boride is a metal boride selected from group IVa, group Va and group VIa of the periodic table of elements, and the spherical band-shaped sealing body according to any one of claims 10 to 16. Production method. The metal borides are titanium boride (TiB), titanium diboride (TiB ₂ ), zirconium diboride (ZrB ₂ ), zirconium dodecaride (ZrB ₁₂ ), hafnium diboride (HfB ₂ ), two Vanadium boride (VB ₂ ), niobium diboride (NbB ₂ ), tantalum diboride (TaB ₂ ), chromium boride (CrB), chromium diboride (CrB ₂ ), molybdenum boride (MoB), two Molybdenum boride (MoB ₂ ), dimolybdenum pentaboride (Mo ₂ B ₅ ), tungsten boride (WB), tungsten diboride (WB ₂ ), ditungsten boride (W ₂ B), dipentaboride the method of manufacturing a spherical annular seal member according to any one of tungsten (W 2 _{B 5)} from at least one of claims 10 to be selected 17.   An aqueous dispersion of a solid lubricant is prepared by mixing hexagonal boron nitride powder and tetrafluoroethylene resin in alumina sol having a hydrogen ion concentration of 2 to 3 in which alumina hydrate particles are dispersed in water containing an acid as a dispersion medium. Claims containing dispersed powder and containing as a solid content a lubricating composition containing 23 to 57% by mass of hexagonal boron nitride, 5 to 15% by mass of alumina hydrate and 33 to 67% by mass of ethylene tetrafluoride resin. Item 19. A method for producing a spherical belt-shaped sealing body according to any one of Items 10 to 18.

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