JPS6213895A - Gasket for seal - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a sealing gasket, and more particularly to a sealing gasket that appropriately seals between a pipe and a pipe joint by expanding the inside of the gasket body. It is.

(Prior art) This type of sealing gasket is, for example, shown in Fig. 9 (A).
, As shown in (B), an inlet 100 and an outlet 110 equipped with a check valve 101 are provided adjacent to a predetermined position of a band-shaped rubber plate 102, and this rubber plate 102 is inserted into a groove-shaped space. An annular rubber gasket with 103/) body 104
It was formed by adhering it to the edge of the opening with an adhesive 105.

By the way, what about sealing gaskets like this?

For example, as shown in FIG. 10, the annular gasket accommodating groove 12Qa formed in the pipe joint 120 is accommodated, and a filler material 130 such as a curable resin is injected at a predetermined pressure (e.g. 50-6
When the filler 130 is injected into the space 103 of the sealing gasket, the air inside is discharged from the exhaust port!10 and the space 103 is filled with the filler 130. Then, when the discharge port 110 is closed and the filler 130 is further injected into the space, the inside of the gasket body 104 expands and comes into strong pressure contact with the outer peripheral surface of the pipe 14G, causing the pipe 140 and the pipe fitting 120 to There is a seal between them.

Therefore, such a sealing gas container is subjected to a product inspection in advance to ensure the reliability of the seal. However, during this product inspection, the same pressure (50 to 60 Kg/
ctn') causes a rupture at the part where the rubber plate 102 and the gasket body 104 are pasted, this pasted part peels off, and the filler 130 in the space 103 is released from the peeled part. A problem with leakage was discovered.

Further, the conventional sealing gasket described above has a space 103.
When injecting the filler 130 into the space 103, a large amount of air remains in the space 103, so a sealing gasket is used to push this air out and fill the space 103 with the filler 130. It is necessary to provide an outlet 110 for removing air.

However, when this sealing gasket is used at a connection point of vertical piping or diagonal piping, the discharge port 110 is oriented laterally (horizontally), resulting in the following inconvenience.

That is, when the filler 130 injected into the space 103 from the injection port 100 reaches the inner opening of the discharge port 11G, the filler 130 flows out from the inner opening even though it is not yet sufficiently filled. It flows out. Therefore, a large amount of air remains in the space 103 of the gasket body 104,
It was extremely difficult or impossible to carry out injections to eliminate this problem.

(Object of the Invention) The present invention was made in view of the above circumstances, and its purpose is to prevent the filling material inside the gasket body from leaking to the outside even if the inside of the gasket body is expanded. Moreover, even when used at the connection point of vertical or diagonal piping, there is no possibility that a large amount of air will remain inside the gasket body, which allows the sealing reliability and sealing effect to be maintained over a long period of time. Our objective is to provide sealing gaskets.

(Structure of the Invention) In order to achieve the above object, the sealing gasket of the present invention has a mold release body embedded inside the rubber gasket body, and a peeling surface that separates from the mold release body inside the gasket body. The present invention is characterized in that an injection port for injecting a filler from the outside is provided between the peeling surface and the mold release body.

(Example) An example of the present invention will be described below with reference to FIGS. 1 to 3.

FIG. 1 shows a longitudinal cross-sectional view of a main part of a sealing gasket G, where 1 is a rubber gasket body. This gasket body 1 includes a gasket portion 1 having an annular configuration.
An annular tongue portion 1b is integrally formed on one side of the tongue portion a, and a plurality of steel balls 8 are fixed in the circumferential direction of the tongue portion 1b. Furthermore, a mold release body 2 is embedded inside the gasket body l along the sealing surfaces 1c and ld. As shown in FIG. 2, this mold release body 2 is made by applying mold release agents 2b, 2b that separate from rubber to the inner and outer peripheral surfaces of a thin steel plate 2a, and forming the mold release agent 2b into a substantially annular shape. By embedding them inside the gasket body 1, peeling surfaces 3a and 3b that peel off from the inner and outer circumferential surfaces of the mold release body 2 are formed inside the gas get body 1. The gasket body l also has an injection port 4 equipped with a check valve 5 for injecting a filler from the outside between the peeling surface 3b and the mold release body 2.
There are designated areas. Note that there is a screw 4 on the outer peripheral surface of this injection port 4.
A is engraved so that a stopper can be screwed into the opening on the outside.

According to such a configuration, when the filler is injected from the injection port 4 at a predetermined pressure, the filler 7 is inserted between the peeling surfaces 3a, 3b and the mold release body 2, as shown in FIG. The inside of the gasket body 1 expands, and the sealing surfaces 1c, ld, and le of the gasket body 1 bulge due to the expansion. Therefore, the seal surfaces 1d and 1e on the outer peripheral surface come into strong pressure contact with the inner peripheral surface of the pipe joint, and the seal surface 1c on the inner peripheral surface side comes into strong pressure contact with the outer peripheral surface of the pipe, thereby preventing the connection between the pipe joint and the pipe. This ensures that the space is sealed. Note that when the space between the peeling surfaces 3a and 3b and the mold release body 2 is expanded,
Cracks are likely to occur at both end portions of the peeled surfaces 3a and 3b. Therefore, it is desirable to form annular release bodies 6.6 with a circular cross section in advance, either integrally or separately, on both ends thereof. In this case, also on the outer peripheral surface of the annular mold release body 6.6! II separation surfaces 3c, 3c are formed.

By the way, the sealing gasket (G) of the above embodiment is manufactured, for example, as follows. That is, first, the mold release body 2 is formed into a substantially annular shape, and the inner opening of the injection port 4 equipped with the check valve 5 is welded or the like at a predetermined position of the mold release body 2 as shown in FIG. It will stick. After that, part of the mold release body 2 and the injection port 4 are placed in an unvulcanized rubber mass, and when this is vulcanized in a mold, a sealing gasket (G) as shown in Fig. 1 is formed. (Note that the steel ball 8 is also fitted into the mold during this formation).

Next, the case where this sealing gasket (G) is used to seal between a pipe and a pipe joint will be described with reference to FIGS. 4 and 5.

FIG. 4 shows a cross section of the pipe joint structure before filling material is injected.
a is inserted to a position where it abuts the positioning step 10b inside the pipe joint 10. The inner circumferential surface of the socket 10a corresponding to the inserted end 20a of the pipe 20 has a gasket housing groove 30 and a tapered surface adjacent to the gasket housing groove 30 whose diameter gradually decreases toward the socket tip outlet. A tapered groove 40 for preventing removal is formed continuously, and a locking flange 50 that bulges inward is provided at the tip of the tapered groove 40 for preventing removal.
are integrally formed.

As seen in FIG. 1, the gasket housing groove 30 is
It has a substantially trapezoidal cross section that widens toward the tube end 20a, and the sealing gasket (G) is loaded into this. still,
The tongue portion tb of the sealing gasket (G) faces the tapered groove portion 40 for preventing extraction together with the steel ball 8.

Now, as shown in FIG. 5, a filler 7, such as a curable filler or water, is injected from the injection port 4 into the peeling surface 3a of the gasket body 1 and the release surface 3a. When injected between the body 2 and the gasket body 2, it expands during this time, and the sealing surfaces 1c, ld, le, etc. of the gasket body 1 also expand. Therefore, the gasket main body 1 fully expands into the gasket housing groove 30 and comes into pressure contact with the end 20a of the tube 20 to exert a sealing effect.

In addition, the expansion of the gasket body 1 is caused by the very high injection pressure of the filler 7 (approximately 50 to 80 kg/crn' in the example), so the taper groove 40 for preventing the tongue portion 1b from being pulled out is
The steel ball 8 is forced into the tapered groove 40 by its expansion pressure, and then bites into the outer surface of the tube 20 by the tapered surface of the tapered groove 40.

Therefore, even if a pulling force is applied to the tube 20, the a+ ball 8 will further bite into the outer surface of the tube 20, and the tube 20 and the pipe fitting 10 will be strongly coupled to resist the pulling force.

In addition, the sealing gasket) G is the peeling surface 3a, 3b.
Since the tube 20 is expanded between the tube 20 and the mold release body 2, the seal will not be broken regardless of the movement of the tube 20 due to the above-mentioned pulling force.

Furthermore, if the filler 7 is made of a curable filler, the M separation surface 3
Since it hardens over time between a, 3b and the mold release body 2, even if the check valve 5 is damaged for some reason during the injection, the filler 7 will not be deformed during the injection. Even if cracks occur, there is no change in volume, and the sealing action and removal prevention force can be maintained semi-permanently.

Further, if the removal preventing member is made of an electrically conductive metal (steel ball 8) as in the above embodiment and is brought into contact with the tapered surface of the tapered groove 40 and the outer surface of the pipe 2o, the pipe 20 and the pipe joint 10 can be electrically connected to each other. Therefore, by applying a predetermined voltage to the pipe 20 and the pipe joint 10 in advance, it is possible to prevent the current from flowing from outside (for example underground), and to effectively prevent electrolytic corrosion of the pipe 20 and the pipe joint 10. can be prevented.

Note that the prevention of the pipe 20 from coming off is not limited to the steel balls 8 as described above, but also the edge portion 8 as shown in FIGS. 6 and 7, for example.
The tube 20' in FIG. 6 may have a resin layer 20'b formed on its outer circumferential surface. The tube 20'' in FIG. 7 is a polyethylene tube with a metal reinforcing tube 20''C installed at the open end.

In addition, the mold release body 2 of the sealing gasket is shown in FIG. 8(A).
, (B) and (C), the peripheral wall made of a steel plate may be formed into a wave shape, an H shape, an X shape, etc., so that the inside of the gasket body 1 can expand more.

Furthermore, the mold release body 2 is not necessarily limited to those described above, and may be made of, for example, a resin (tetrafluoroethylene resin, etc.), which means that it can withstand the heat and pressure during vulcanization of the gasket body Any material may be used as long as it separates from the material (rubber) of the gasket body.

Additionally, the shape of the gasket body and the shape of the release body vary depending on the shape of the object to be sealed, and therefore are not necessarily limited to the annular shape as described above.

(Effects of the Invention) The sealing gasket of the present invention configured as described above has the following beneficial effects. That is, ■ Since the present invention allows an injection-type sealing gasket to be constructed without pasting with adhesive, there is no possibility that the pasted part will peel off due to rupture and the filler will leak. The filler can be reliably contained within the gasket body, and the sealing effect can be exhibited for a long period of time.

■ When injecting the filler into the inside of the gasket body, there is no large amount of air inside the gasket body as in the past, so there is no need to vent air when injecting the filler, and there is no need for vertical or diagonal piping. Even when used at a connection point, a large amount of air does not remain inside the gasket body, and the filling material can be injected and filled into the gasket body accurately.

■ Also, due to the fact that a large amount of air is not trapped inside the gasket body, there are also the following useful advantages.

(1) The sealing gasket can be significantly downsized, and the pipe fittings made to match this sealing gasket can also be significantly downsized and lightweight.

(i) Manufacturing is easy because there is no need to provide a discharge port as in the conventional case.

(ii) Since the amount of filler injected is significantly reduced compared to the conventional method, the injection work can be completed in a short time and the work can proceed quickly.

(1v) Costs can be significantly reduced by reducing the amount of filler injection, downsizing the sealing gasket, and simplifying and facilitating production.

As described above, the sealing gasket according to the present invention not only has a practically useful effect, but also can greatly contribute to the development of industry.

[Brief explanation of drawings]

Figures 1 to 3 show an embodiment of the present invention, Figure 1 is a vertical cross-sectional view of the main part of a sealing gasket, Figure 2 is a vertical cross-sectional view of a mold release body, and Figure 3 is a vertical cross-sectional view of a sealing gasket. Fig. 4 is a vertical cross-sectional view of the main part showing the state in which the inside of the pipe is inflated;
The figure is a vertical cross-sectional view of the main part showing a state in which the sealing gasket installed in the pipe joint is inflated by the filler, and FIGS. 8(A), (B), and (C) are longitudinal sectional views of main parts, and FIG.
Figures (A), (B) and Figure 10 show conventional examples;
Figure (A) is a vertical sectional view of the main part of the sealing gas get, Figure 9 (B) is a front view showing a part of the sealing gasket, and Figure 9 (B) is a front view showing a part of the sealing gasket.
FIG. 0 is a vertical cross-sectional view of a main part showing a state in which a sealing gasket is installed in a pipe joint and the inside of the gasket is expanded by a filler. G...Sealing gasket...Gasket body 2...Release body 3a, 3b...Peeling surface 4...Inlet a...Filler patent applicant Agent of Nippon Steel Pipe Fittings Co., Ltd.
Patent Attorney Takashi Suzue - Figure 1 et al Figure 2 Figure 8 Figure 10 Procedural amendment 416% July 15th JPO Commissioner Michibe Uga Seal gasket Nippon Steel Pipe Fitting Co., Ltd. Voluntary (1) Part of the specification On page 11, line 5, “For example, resin.”
Correct it as follows. ``For example, even if the vertical cross section is formed in a circular shape as shown in Figure 9 (A), or the vertical cross section is formed in an elliptical shape as shown in Figure 9 (B), etc. Also, this mold release body 2 may be made of, for example, a resin.'' (2) The entire text of page 14 of the same book is revised as shown in the attached sheet. (3) In the drawings, the figure numbers "Figure 9 (AOB)" and "Figure 10" have been corrected to "Figure 10 (AOB)" and "Figure 11," respectively, as shown in red ink on the attached sheet. (4) In the drawings, as shown in the attached sheet, Figure 9 (A) (B)
). Above [attached sheet] Longitudinal cross-sectional views of main parts, Figure 8 (A), (B),
CC) is a schematic vertical sectional view showing other modified examples of the 11-type body, and FIGS. 9(A) and 9(B) are schematic longitudinal sectional views showing other modified examples of the mold release body, respectively. Sectional longitudinal sectional view, Fig. 10 (A),
(B) and Fig. 11 show the conventional example, and Fig. 1O (A)
Figure 10 (B) is a vertical sectional view of the main part of the sealing gasket.
11 is a front view showing a part of the sealing gasket, and FIG. 11 is a longitudinal cross-sectional view of the main part showing a state in which the sealing gasket is installed in a pipe joint and the inside of the gasket is expanded by a filler. G...Sealing gasket...Gasket body 2...Release body 3a, 3b...Peeling surface 4...Inlet? ... Filler patent applicant Agent of Nippon Steel Pipe Fittings Co., Ltd.
Patent Attorney Takashi Suzue - Figure 9 (A) Figure 9 CB) Chi

Claims (1)

[Claims] A release body is buried inside the rubber gasket body to form a release surface that separates from the release body inside the gasket body, and a filler is applied from the outside between this release surface and the release body. A sealing gasket characterized by having an injection port for injection.