JP2600887Y2 - Sealing material - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a sealing material. Its purpose is to exhibit extremely excellent mechanical strength, but at the same time, it is excellent in sealing and sliding properties, and does not damage other metal surfaces during sealing. It is an object of the present invention to provide a sealing material which has both flexibility and rigidity and is suitably used for sealing under high temperature and high pressure.

[0002]

2. Description of the Related Art Sealing materials such as packings and gaskets are sandwiched between joint surfaces requiring airtightness and liquid tightness, or packed around a rotating or reciprocating shaft, so that liquid or gas leaks from sliding parts. Is used to prevent Such sealing materials may be of various shapes depending on the place of use and the environment, etc., but generally have little wear due to sliding, a small coefficient of friction, and do not corrode the mating metal surface, In addition, it is a condition that the sealing material should have, such as being chemically stable to a fluid, and having excellent heat resistance and pressure resistance. As such a sealing material, asbestos or heat-resistant rubber resistant to high temperatures has been used as a material for a long time, but in recent years, expanded graphite excellent in self-lubricating properties, thermal conductivity, chemical resistance, etc. has been mainly used. It is becoming.

[0003] However, although expanded graphite has the above-mentioned excellent properties, it has a drawback of low tensile strength and brittleness, and therefore is not used alone, and is usually braided with a reinforcing material. Often used. An example of this is a braided gland packing as shown in the sectional view of FIG. This gland packing (P) is formed between a braid (b) formed by lattice knitting of 20 knitting yarns (a) and all the knitting yarns (a) appearing on the end surface of the braid (b). Were formed from a plurality of expanded graphite sheets (c) each of which was inserted and filled in the gaps along the longitudinal direction of the braided body (b).

As the knitting yarn (a), high-strength fibers such as metal fibers, glass fibers, aramid fibers, polytetrafluoroethylene fibers, asbestos fibers, carbon fibers, and ceramic fiber fibers are used. It was one of the sealing materials excellent in the sealing function, which can make use of the characteristics provided and can compensate for the weakness of the tensile strength and the brittleness by the high-strength fiber.

[0005]

SUMMARY OF THE INVENTION However, the gland packing (P) made of the high-strength fiber braid described above.
In, when used under severe conditions such as high temperature, high pressure, etc., because the amount of high-strength fiber used is large, depending on the place of use, sliding of high-strength fiber appearing on the surface,
There is a problem that the metal surface of the partner may be damaged. Therefore, the industry has excellent mechanical strength that can be used especially under high temperature and high pressure,
Even if the number of high-strength fibers used per unit area increases, it has been desired to create a sealing material which does not damage the mating metal surface due to sliding and has excellent sealing properties.

[0006]

According to the invention, a sealing material is formed by winding a tape material made of expanded graphite around a wire rod bundle made of a high-strength material, and the tape material made of expanded graphite has fine pores. Formed of a laminate of a thin sheet of porous polytetrafluoroethylene (PTFE) made of porous polytetrafluoroethylene (PTFE) and a flexible expanded graphite sheet, and the reinforcing sheet appears on the surface of the sealing material. By providing a sealing material characterized by being arranged as described above, all of the conventional problems described above are solved.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the sealing material according to the present invention will be described below with reference to the drawings. FIG. 1 is an external view of a sealing material (1) according to an embodiment of the present invention. As shown in the drawing, in the present invention, a tape material (3) made of expanded graphite is wound around the surface of a wire bundle (2) made of a high-strength material to form a sealing material (1).

Examples of the high-strength material include synthetic resin fibers such as aramid fibers and polytetrafluoroethylene fibers impregnated with lubricating oil, metals such as Monel metal, Inconel, stainless steel, copper, and aluminum, carbon fibers, and glass fibers. Any material having the necessary strength as a sealing material such as ceramic fiber fibers can be used without any particular limitation. The wire bundle (2) is formed from the high-strength material as described above. The wire bundle (2) is formed by bundling a plurality of wires (20). As the wire (20), any material can be suitably used as long as it is formed from the high-strength material. However, it is preferable that the diameter is 3 mm or less from the viewpoint of manufacturing. Further, in the present invention, the wire bundle (2) is obtained by bundling a plurality of wires (20) or by knitting a wire (20) made of one high-strength material into one string. Further, a bundle obtained by bundling a plurality of wires (20) and knitting or assembling them to form a cord is preferably used.

A plurality of wires (20) are bundled to form a string (2)
In this case, ordinary braided cords, hammered braids, braids, and the like are preferably used without any particular limitation. Specifically, for example, a circular braid formed by a plurality of wires (20) as shown in FIGS. 2 and 3, or a braid such as a square braid as shown in FIGS. Round cords, squared cords and the like are preferably exemplified. It should be noted that, also in the above-mentioned hammering string, any hitting method such as four hitting, eight hitting, sixteen hitting can be adopted. Further, other than the above, a bag-shaped string, a fixed string, or the like can be adopted without limitation. Alternatively, as shown in FIG. 6, a wire obtained by bundling a plurality of wires (20) as they are and twisting them can be suitably used.

A tape material (3) made of expanded graphite is wound on the surface of the wire bundle (2) as described above. As the tape material (3), as shown in FIG.
What is formed by the laminated body of 2) and the flexible expanded graphite sheet (31) can be used. Here, as the flexible expanded graphite sheet (31), natural graphite, pyrolytic graphite, quiche graphite, or other graphite powder is reacted with concentrated sulfuric acid, concentrated nitric acid, or the like to temporarily form an interlayer compound, and then washed with water. To expand into a residual compound, which is rapidly heated and expanded to obtain a flexible compound.

As the reinforcing sheet (32), among those having good lubricity and corrosion resistance, appropriate mechanical strength and chemical stability against fluid, it is preferable to use polytetrafluoroethylene (PTFE). it can. Among them, the diameter is 0.
A porous thin film made of polytetrafluoroethylene (PTFE) having fine pores of about 05 to 15 μm can be more preferably used because the lamination with the expanded graphite sheet (31) is good. This porous polytetrafluoroethylene (PT
The thin film made of FE) is made of polytetrafluoroethylene (PTFE).
After the molding powder is compacted and then rapidly stretched, a material having a porosity of about 25 to 95% can be suitably used.

When the tape material (3) having a laminate structure as described above is employed, the expanded graphite sheet (31) has a density of 0.80 to 2.2 g.
/ Cm, and those having crystal-level irregularities on the surface are preferably used. The reason is that if the density of the expanded graphite sheet (31) exceeds 2.2 g / cm, the structure becomes too dense and the reinforcing sheet (3)
This is because the lamination with 2) is not performed favorably and the anchor effect is hardly generated, which is not preferable. The thickness of the expanded graphite sheet (31) is not particularly limited, but is preferably about 0.1 to 1.5 mm. The reason for this is that if the thickness of the expanded graphite sheet (31) is less than 0.1 mm, the excellent heat resistance, corrosion resistance, and abrasion resistance of the expanded graphite cannot be sufficiently exhibited, while the thickness is reduced. If it exceeds 1.5 mm, on the contrary, the brittleness, which is a disadvantage of the expanded graphite, appears, which is not preferable in any case. Furthermore, a reinforcing sheet (32)
The thickness of is not particularly limited, but 0.001 to
It is preferably about 0.15 mm from the viewpoint of manufacturing.
The reinforcing sheet (32) and the expanded graphite sheet (3)
The lamination with 1) may be performed via an appropriate adhesive or the like as appropriate. The tape material (3) may be formed, and there is no particular limitation.

A tape material (3) comprising a laminate of the above expanded graphite sheet (31) and reinforcing sheet (32)
Is wound around the wire bundle (2) to obtain the sealing material (1) according to the present invention. The winding method of the tape material (3) is not particularly limited, and the tape material (3) may be wound on the surface of the cord (2) in a single or double order, or may be wound on the surface of the wire bundle (2). The tape material (3) is covered, and both the tape material (3) and the wire bundle (2) are twisted while being twisted, and the tape material (3) is wound around the surface of the wire bundle (2). Any appropriate method can be suitably adopted. still,
In the latter winding method, a sealing material (1) in which the wire bundle (2) and the tape material (3) are twisted together is obtained.

In the sealing material (1) configured as described above, as shown in the sectional view of FIG. 8, the amount of the wire (20) made of a high-strength material used per unit area increases, and And the surface is covered with a tape material (3) made of expanded graphite, so that the sealing characteristics of the expanded graphite are sufficiently exhibited, and furthermore, the mating metal surface is damaged by sliding. Nothing. Therefore, since extremely high mechanical strength is exhibited, it can be used, for example, as a substitute for a bush or a spacer in a high-temperature, high-pressure environment.

As a tape material (3) wound around the wire bundle (2), an expanded graphite sheet (31) is formed on one side of an electrically insulating reinforcing sheet (32) such as polytetrafluoroethylene (PTFE). ) Laminated tape material (3)
When the sealing material (1) is formed by being wound around the surface of the wire bundle (2) using an electric insulating reinforcing sheet (polytetrafluoroethylene (PTFE)) on the surface of the sealing material (1). By adopting a configuration in which 32) appears, a sealing material having no conductivity can be obtained. Therefore, for example, a spherical valve box (A) provided with a flow path (A-1) as shown in FIG. 9, a valve cover (F) covering the valve box (A), and a valve seat (B) Of a globe valve constituted by a valve body (C) that opens or closes a flow path (A-1) by pressing or separating from a valve, a handle (H) for operating the valve body (C), and a valve rod (D). By filling and using the sealing material (1) as shown in FIG. 8 in the joint between dissimilar metals, that is, in the gap (Z) between the valve lid (F) and the valve stem (D), excellent performance is obtained. It is possible to prevent electrical corrosion between these dissimilar metals as well as sealing properties, slidability, heat resistance, corrosion resistance and mechanical strength.

The sealing material (1) as described above is particularly suitable for use in FIG.
It is molded into a ring shape as shown in FIG. 0, and is suitably used as a gasket or a packing in a portion requiring liquid tightness and air tightness. Further, it may be formed into any shape other than the above-mentioned ring shape and used.

[0017]

As described above in detail, this invention is a sealing material in which a tape material made of expanded graphite is wound around a wire bundle made of a high-strength material, and the tape material made of expanded graphite is fine. It is formed of a laminate of a reinforcing sheet made of a porous polytetrafluoroethylene (PTFE) thin film having pores and a flexible expanded graphite sheet, and the reinforcing sheet is provided on the surface of the sealing material. Since it is a sealing material characterized by being arranged so as to appear, there are many high-strength fiber materials used per unit area, and while having extremely excellent mechanical strength, good sealing properties and sliding properties Exhibiting rigidity and flexibility at the same time,
In addition, an excellent effect of exhibiting excellent sealing characteristics as a sealing material under a high-temperature and high-pressure environment, such as not damaging a mating metal surface, is exhibited. Also, by using a laminate of expanded graphite sheet and reinforcing sheet as a tape material,
A sealing material that is used for the joint between dissimilar metals and that can prevent electrical corrosion, or that can further increase the strength of the sealing material. It has the effect of being able to.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing one embodiment of a sealing material according to the present invention.

FIG. 2 is an external view showing an example (a circular braided string) of a wire bundle (string body) which is one of the components of the sealing material according to the present invention.

FIG. 3 is an external view showing an example (a circular knitted string) of a wire bundle (string body) which is one of the components of the sealing material according to the present invention.

FIG. 4 is an external view showing an example (square braided string) of a wire bundle (string body) which is one of the components of the sealing material according to the present invention.

FIG. 5 is an external view showing an example (square braided string) of a wire bundle (string body) which is one of the components of the sealing material according to the present invention.

FIG. 6 is an external view showing an example of a wire bundle (string body) which is one of the components of the sealing material according to the present invention.

FIG. 7 is a sectional view showing a tape material which is one of the components of the sealing material according to the present invention.

FIG. 8 is a cross-sectional view showing a configuration of an embodiment of the sealing material according to the present invention.

FIG. 9 is a cross-sectional view illustrating a state in which the sealing material according to the present invention is filled in a dissimilar metal joint of a fluid device.

FIG. 10 is an external view showing a state in which the sealing material according to the present invention is formed into a ring shape.

FIG. 11 is an explanatory sectional view showing an example of a conventional braided packing using expanded graphite.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 sealing material 2 wire bundle 20 wire 3 tape material 31 expanded graphite sheet 32 reinforcing sheet

Claims (1)

(57) [Scope of request for utility model registration] 1. A sealing material formed by winding a tape material made of expanded graphite around a wire bundle made of a high-strength material ,
The tape material made of expanded graphite is a multi-hole tape having fine pores.
From a thin film made of porous polytetrafluoroethylene (PTFE)
To a laminate of a flexible sheet and a flexible expanded graphite sheet
And formed on the surface of the sealing material.
It is characterized by being arranged so that the reinforcing sheet appears
To seal material.