JP2528365Y2 - Expanded graphite gasket having auxiliary sealing member and sealing mechanism - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an expanded graphite gasket having an auxiliary sealing member suitably used for sealing a pressure vessel, a fluid device, etc., and particularly to a valve shaft, and using the expanded graphite gasket. The present invention relates to a sealing mechanism.

[0002]

2. Description of the Related Art A gasket of this type comprises an annular expanded graphite molded body obtained by applying a compressive force from an axial direction in a state where an expanded graphite tape is laminated and wound in an annular shape. In a state of being housed in the inner periphery of the device, the member is fastened and fixed from the axial direction via a positioning / fixing member such as a retainer ring.

[0003] This expanded graphite gasket has been highly evaluated for its properties such as appropriate flexibility and self-lubricating properties of graphite.
When placed at a high temperature of 0 ° C or higher, oxidation loss occurs.
There was a restriction on the operating temperature. In the case of being formed only of expanded graphite, when tightened and fixed as described above, the end face in the axial direction of the annular expanded graphite molded body is positioned with a positioning / fixing member such as a retainer ring and the inner periphery of the pressure vessel. In some cases, and as a result, there is a disadvantage that the sealing function is reduced due to stress relaxation.

For this reason, conventionally, as a means for preventing the extruded graphite material from exuding, for example, Japanese Utility Model Publication No. Sho 63-29972.
An expanded graphite gasket having a configuration as disclosed in Japanese Patent Application Laid-Open Publication No. H11-209,878 has been proposed. That is, in the conventional gasket in which the stress relaxation due to protrusion is not generated, as shown in FIG. 7, a thin metal wire is formed on both end surfaces 1a and 1b of the annular expanded graphite molded body 1 in the axial direction (tightening direction). Knitted sheet 6
1 and 61 are attached and fixed respectively. As shown in FIG. 8, such an expanded graphite gasket has a lid 12 inserted through a shaft hole in a pressure vessel 11 and the lid 12 is
The gasket contact surface 14 is interposed between the gasket contact surface 14 and the retainer ring 13 externally fitted to the lid 12 so as to be opposed to the gasket contact surface 14, and tightened and fixed from the axial direction via a tension bolt 15. The pressure vessel 11 is in close contact with the inner peripheral surface 11a of the pressure vessel 11 and the outer peripheral surface 12a of the lid 12, and is used to seal between the two.

[0005]

In the conventional expanded graphite gasket having the above-mentioned structure, the annular expanded graphite molded article 1 is tightened in the axial direction at the time of fastening by the thin metal wire knitted sheets 61, 61. Although the gap G can be prevented, the gap G between the pressure vessel 11 and the retainer ring 13 is small, and the air (oxygen) on the atmospheric side also passes through the metal thin wire knitted sheet 61 from the gap G and the annular expanded graphite molded body. 1, under the high temperature condition of 400 ° C. or higher, the volume of the expanded graphite was apt to decrease with time due to the oxidizing action, and the sealing function tended to deteriorate early.

The present invention has been made in view of the above-described circumstances. By providing a metal auxiliary seal member on the inner peripheral surface and the outer peripheral surface of the expanded graphite molded body, it is possible to reduce the gap between the peripheral members of the gasket. While effectively preventing exudation, preventing intrusion of air from the atmosphere side and eliminating volume reduction due to high-temperature oxidation of the expanded graphite molded body, it is good for a long time even when used under a high temperature of 400 ° C or more. It is an object of the present invention to provide an expanded graphite gasket having an auxiliary sealing member capable of maintaining a sealing function and a sealing mechanism.

[0007]

In order to achieve the above object, an expanded graphite gasket according to the present invention is provided on an end face in the axial direction of an annular expanded graphite molded body, and an inner peripheral surface of the annular expanded graphite molded body. A metal auxiliary seal member having an inner peripheral side bent edge portion and an outer peripheral side bent edge portion slightly extending on the outer peripheral surface side is fitted and fixed.

In particular, in the above-described expanded graphite gasket, it is preferable that the metal auxiliary seal members are fitted and fixed to both end surfaces in the axial direction of the annular expanded graphite molded body. desirable.

Further, the auxiliary seal member is fitted to one of the inner peripheral surface and the outer peripheral surface of one end surface or both end surfaces in the axial center direction of the annular expanded graphite molded product. It may be fixed.

Further, the sealing mechanism according to the present invention has an annular expansion.
One or both of the end faces in the axial direction of the gasket made of graphite
Inner and outer peripheral surfaces of the compression member in contact withEach of
ToThe annular expanded graphite gasket
To the inner and outer peripheral surfaces of theExtensionBe doneMetal supplement
An auxiliary seal member is provided.

[0011]

According to the gasket made of expanded graphite having the auxiliary seal member of the present invention, the gasket is fitted to, for example, a shaft hole in a pressure vessel, and the auxiliary seal member side fitted to the axial end face is set to the atmosphere side. When the lid is inserted, and the lid is tightened from the axial center direction by a tension bolt via a retainer ring positioned by screws or split rings,
The expanded graphite molded body is compressed, and accordingly, the inner peripheral side bent edge and the outer peripheral side bent edge of the auxiliary seal member and the inner peripheral surface and the outer peripheral surface of the expanded graphite molded body are radially inward and outward. To the inner surface of the pressure vessel and the outer surface of the lid, and both are sealed. At this time, a tightening force acts on the annular expanded graphite molded body, but a part of the annular expanded graphite molded body is prevented from protruding in the axial direction by the end face regulating action of the auxiliary sealing member. Since the presence of the sealing member also prevents air from entering from the atmosphere side, even when used under high temperature conditions of 400 ° C. or more, volume reduction due to oxidation of the expanded graphite is suppressed, and the sealing performance is maintained over a long period of time. Can be maintained well.

In particular, when the metal auxiliary seal member is fitted and fixed to both end faces in the axial direction of the annular expanded graphite molded body, even when the oxygen-injected fluid is used, the oxygen is annular. Intrusion into the expanded graphite molded body is prevented, and the volume reduction of the molded body can be suppressed.

Further, according to the sealing mechanism of the present invention, only the compression member will compress operation, the annular from the end of the respective circumferential surfaces provided on the inner peripheral surface and the outer peripheral surface of the compression member
The metal auxiliary seal member extending toward the inner and outer peripheral surfaces of the expanded graphite gasket is deformed radially inward and outward with the compression of the expanded graphite gasket, and the inner periphery of the pressure vessel is expanded. It is possible to adhere to the surface and the outer peripheral surface of the lid, and to seal them both in the same manner as described above.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a semi-longitudinal sectional view showing an embodiment of the present invention applied to a gasket made of expanded graphite having a substantially square cross section, and the same components as those in the conventional example shown in FIG. And their description is omitted.

In FIG. 1, reference numeral 3 denotes a ring-shaped auxiliary sealing member made of a metal, for example, stainless steel, made of a thin plate having a thickness of about 0.05 mm, and integrally manufactured for the inner and outer circumferences. The inner peripheral side bent edge portion 3a slightly extending to the inner peripheral surface 1c and the outer peripheral surface 1d side
And an outer bent edge 3b. The auxiliary sealing member 3 is so formed that the inner and outer bent edges 3a and 3b thereof are substantially flush with the inner and outer peripheral surfaces 1c and 1d of the annular expanded graphite molded article 1, respectively. The expanded graphite molded body 1 is fitted and fixed to one end surface 1a in the axial direction.

The gasket thus constructed is used as shown in FIG. 2, for example, for sealing a shaft of a pressure vessel.
And fixed with a retainer ring 13 and tightened with a tension bolt 15 from the axial direction. In FIG. 2, the same parts as those in the conventional example shown in FIG. 8 are denoted by the same reference numerals, and the description thereof will be omitted.

The metal auxiliary seal member 3 is deformed by the tightening force of the tension bolt 15 and the pressure vessel 11
Is tightly attached to the inner peripheral surface 11a and the outer peripheral surface 12a of the lid 12, and a sealing function is provided between the two. At this time, the tightening force acts on the annular expanded graphite molded body 1. However, since the metal auxiliary seal member 3 fixed to the end surface 1a of the annular expanded graphite molded body 1 functions as a regulating plate, the molded body 1 The portion is effectively prevented from protruding into the gap G between the inner peripheral surface 11a of the pressure vessel 11 and the outer peripheral surface of the retainer ring 13, so that the above-described sealing function is favorably maintained for a long period of time.

Even if the air on the atmosphere side attempts to enter the gasket side from the gap G, the corner portions 1e and 1f on the inner and outer circumferences of the annular expanded graphite molded body 1 are covered by the metal auxiliary seal member 3. Therefore, the invasion of the air is prevented, and the possibility that the expanded graphite in the molded body 1 is oxidized and consumed is eliminated, and high sealing performance is exhibited over a long period of time even under a high-temperature use condition.

FIG. 3 is a diagram showing a result of mounting a sample of the expanded graphite gasket according to the present invention on the shaft sealing portion of the pressure vessel and confirming a change in weight of the annular expanded graphite molded body 1 in comparison with that of the conventional product. It is. Here, the gap G between the pressure vessel 11 and the lid 12 is determined as an accelerated test by using a generally used JIS.
The standard gap of B0401, which is about the size of the gap, and +0.6 mm and +0.9 mm respectively,
An example when the test temperature is set to 600 ° C. is shown. The broken lines a and b in FIG. 3 indicate the characteristics of the product of the present invention when the standard gap and the enlarged gap are applied, respectively, and the broken lines c and d indicate the characteristics of the conventional product when the standard gap and the enlarged gap are applied, respectively. As is clear from the characteristics shown in FIG. 3, when the gap G on the atmosphere side is standard, there is almost no heat loss under the conditions of the accelerated test at 600 ° C., and even under disadvantageous conditions where the gap G is enlarged. It was found that heat loss was small and oxidation of expanded graphite was effectively prevented.

FIG. 4 is a diagram showing the result of the water pressure resistance test performed on the product of the present invention in comparison with that of the conventional product. In FIG. β is the water pressure resistance of the conventional product. As is clear from the characteristics shown in FIG. 4, it was found that the final waterproof pressure can be maintained at a high level in the product of the present invention even if the amount of increase in the gap is large.

FIG. 5 shows another embodiment of the present invention. Auxiliary metal sealing members 3, 3 each having a thickness of about 0.2 mm are provided on both end surfaces 1a, 1b of the annular expanded graphite molded body 1 in the axial direction. It is fitted and fixed. In the case of this other embodiment, the same effects as those of the above-described embodiment are exhibited, and it is possible to cope with a use situation in which oxygen is dissolved in the internal fluid.

For example, in a piping system such as a boiler, problems such as an increase in piping resistance due to generation of scale in the pipe and an increase in load on a water supply pump have been problematic. As a method, an oxygen treatment method in which oxygen is positively injected into a fluid has been devised. In that case, for the gasket, the fluid side also becomes an oxidizing atmosphere, and there is a great risk of oxidation of the annular expanded graphite molded body 1 as it is. Here, as described above, the other end face 1b of the annular expanded graphite molded body 1 in the axial direction is provided.
In addition, the use of the gasket provided with the metal auxiliary seal member 3 prevents the oxygen-injected fluid from entering the expanded graphite molded body 1, so that it can be used as a seal for a piping system to which the oxygen treatment method is applied. It can be used without hindrance.

FIG. 6 is a semi-longitudinal sectional view showing the sealing mechanism of the present invention. The gasket made of expanded graphite having the configuration as described in the above embodiment is brought into contact with the axial end face of the gasket. Each of the inner and outer peripheral surfaces of the retainer ring 13 which is a compression member to be compressed is provided with an end of the inner and outer peripheral surfaces.
From inner part to inner peripheral surface and outer peripheral surface of annular expanded graphite molded body 1
The metal auxiliary seal members 3A and 3B are fitted and fixed in such a state that almost half of the length in the axial direction is extended toward . Also in this case, similarly to the above-described embodiments, the sealing function is favorably maintained for a long time by preventing the annular expanded graphite molded article 1 from protruding. In this embodiment, the auxiliary seal member may be provided on only one of the inner and outer peripheral surfaces of the retainer ring 13.

In each of the embodiments described above, the cross-section of the expanded graphite molded body 1 is substantially square, and a thin stainless steel plate is used as the metal auxiliary seal member 3.
The cross-sectional shape of the gasket and the material and thickness of the auxiliary seal member 3 can be arbitrarily changed. For example, the cross-section of the gasket can correspond to any shape such as a round shape, a rectangular shape, a hexagonal shape, and a wedge shape. It is. Also, if titanium or the like is used for the material of the auxiliary seal member 3, improvement in corrosion resistance and strength can be expected at the same time, and the plate thickness can be arbitrarily set in accordance with the size of the gasket and use conditions. is there.

[0025]

As described above, according to the first aspect of the present invention, the metal having the inner peripheral side bent edge portion and the outer peripheral side bent edge portion on the axial end surface of the annular expanded graphite molded body. By fitting and fixing the auxiliary sealing member made of a material, it is possible not only to prevent a part of the annular expanded graphite molded body from protruding from the end face due to a tightening force when mounted on a pressure vessel or the like, but also to prevent the air side from being exposed. Can prevent the infiltration of air, so that there is no volume loss due to oxidative consumption of the expanded graphite, and the initial sealing performance is improved by 4%.
Even under a high temperature condition of 00 ° C. or more, it can be favorably maintained for a long time.

According to the second aspect of the present invention, since the metal auxiliary seal members are fitted and fixed to both end faces in the axial direction of the annular expanded graphite molded body, even in the usage mode for handling the oxygen injection fluid, The oxidative consumption of the expanded graphite can be suppressed, and the effect of maintaining the sealing performance can be further enhanced.

Furthermore, according to the present invention, the inner and outer peripheral surfaces of the compression member for compressing the annular expanded graphite gasket in the axial direction are respectively provided on the inner and outer peripheral surfaces from the ends of the inner and outer peripheral surfaces.
Since the metal auxiliary seal member is provided to extend toward the inner and outer peripheral surfaces of the gasket made of expanded graphite , the sealing effect is exerted in the same manner as described above simply by compressing the compression member. be able to.

[Brief description of the drawings]

FIG. 1 is a half longitudinal sectional view showing an expanded graphite gasket according to an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view showing a state in which the gasket made of expanded graphite in the embodiment is mounted for sealing a shaft of a pressure vessel.

FIG. 3 is a characteristic diagram showing a change in weight of an expanded graphite gasket in the same example as that of a conventional product.

FIG. 4 is a characteristic diagram showing a result of a water pressure resistance test of the expanded graphite gasket in the same example as that of a conventional product.

FIG. 5 is a half longitudinal sectional view showing an expanded graphite gasket according to another embodiment of the present invention.

FIG. 6 is a half longitudinal sectional view showing the sealing mechanism of the present invention.

FIG. 7 is a semi-longitudinal sectional view showing a conventional expanded graphite gasket.

FIG. 8 is a half longitudinal sectional view showing a state in which a conventional expanded graphite gasket is mounted for sealing a shaft of a pressure vessel.

[Explanation of symbols]

 Reference Signs List 1 annular expanded graphite molded article 1a, 1b End face of annular expanded graphite molded article 1c inner peripheral surface of annular expanded graphite molded article 1d outer inner peripheral surface of annular expanded graphite molded article 1e, 1f corner of annular expanded graphite molded article 3 metal Auxiliary seal member made of metal 3a Inner peripheral bent edge of metal auxiliary seal member 3b Outer / inner peripheral bent edge of metal auxiliary seal member

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor: Yu Fujiwara 1 541, Shimouchi-jinji battering ground, Mita City, Hyogo Prefecture Nippon Pillar Industry Co., Ltd. Mita Plant (56) References U) Hikaru 4-101071 (JP, U)

Claims (4)

(57) [Scope of request for utility model registration] 1. An inner peripheral side bent edge portion and an outer peripheral side fold slightly extending to an inner peripheral surface and an outer peripheral surface side of the annular expanded graphite molded body, respectively, at an axial end surface of the annular expanded graphite molded body. An expanded graphite gasket having an auxiliary seal member, wherein a metal auxiliary seal member having a curved edge is fitted and fixed. 2. An expanded graphite gasket having an auxiliary seal member according to claim 1, wherein the metal auxiliary seal member is fitted and fixed to both end faces in the axial direction of the annular expanded graphite molded body. 3. The auxiliary sealing member of the annular expanded graphite molded body is fitted and fixed to one of the inner peripheral surface and the outer peripheral surface of one end face or both end faces in the axial direction of the annular expanded graphite molded article. An expanded graphite gasket having the auxiliary seal member according to claim 1. 4. A respective inner and outer peripheral surfaces of the compression member in contact with one or both of the end faces in the axial direction of the annular expanded graphite gasket, the ring thereof from the end portion of the peripheral surface
Jo expanded graphite gasket inner circumferential surface and the sealing mechanism, characterized in that a metallic auxiliary sealing member is out <br/> extending toward the outer circumferential surface.