JP3392174B2 - Gasket-integrated flange joint - Google Patents

Description

Detailed Description of the Invention

[0001]

[Industrial application] The present invention relates to a rubber hose and a rubber joint for pumping or sucking a fluid.

[0002]

2. Description of the Related Art When connecting a rubber hose to a counterpart pipe, most of them use a steel flange, and when the steel pipe is inserted into the end of the rubber hose and the pipe and the rubber hose are firmly bound, the internal fluid is pumped. A method in which a steel pipe and a steel flange are welded and a gasket such as asbestos or rubber is used to seal the contact surface with the mating flange.
..A method (see FIG. 6) and the inner surface rubber of the rubber hose is expanded at the end and integrated with the flange, and the expanded inner surface rubber serves as a gasket as a sealant ... B The method (see FIG. 7) is roughly classified into two.

[0003]

The method A, which uses a gasket when tightening the flange integrated with the rubber hose, is the most general-purpose method in general construction for connecting pipes. The method B omits the work of attaching the gasket. In the case of method B, it is a rubber gasket made of the same material as the inner rubber of the hose, and when it is compressed by a bolt to obtain a sealing pressure, it deforms like method C (see FIG. 8). A soft rubber is used as the inner rubber of the hose from the viewpoint of maintaining its flexibility, which causes a large deformation in the gasket portion. The amount of deformation is proportional to the thickness of rubber and inversely proportional to the hardness of rubber. That is, when the rubber thickness is large, the deformation is large, and when the rubber is soft, the deformation is large. On the other hand, since the sealing pressure is proportional to the compression surface pressure of rubber, the deformation becomes particularly large when the rubber is pressure-fed. Rubber tends to break if it is used in excess of a certain amount of deformation. With a rubber hose integrated with a gasket rubber, a protrusion is provided on the circumference of the gasket to prevent the gasket from breaking, and a high sealing pressure may be produced locally, which is often used as a method to prevent rubber from breaking due to deformation. Since the area of the high-pressure seal portion is small, the limit value of pressure is limited. In a rubber hose, when a steel flange is used and a gasket such as asbestos is used as a sealing material to connect to a mating flange, a nipple portion that connects the rubber portion and the flange is required.
・ ・ ・ Method A This nipple part needs a length for bonding with rubber and pressure clamping, and generally requires a length equal to or larger than the hose diameter. The length of the hose will be increased by adding, so it will inevitably become a long hose. Therefore, the cost is high, the weight is large, and the mounting pipe distance is long, so that it is applied to a hose having a relatively small diameter. Especially, it is not suitable for use in a building structure where the piping distance is limited. On the other hand, when the inner rubber of the hose is extended as it is to form a gasket as in method B,
Since the nipple portion is not required, the flexibility of the hose is maximized, and the hose can be made into a short length. Moreover, it is not necessary to use a new gasket and the mounting is easy. In the structure of the B method, it seems that the same effect as that of the hose of the A method can be obtained by sealing with a gasket that is resistant to high pressure, such as asbestos, on both end faces, but it is crimped by bolts. In this case, only the low-rigidity rubber part is deformed, causing the same problem as the above. In the structure where the inner surface rubber and the gasket, which are sufficiently flexible with a short hose, are integrated,
There is a need for a structure of a gasket-integrated high-pressure seal rubber joint that does not cause damage, deformation, or uneven distribution of surface pressure even when high surface pressure is applied to the gasket.

[0004]

[Means for Solving the Problems] The inner surface rubber, which requires flexibility to maintain the flexibility as a hose, is used as it is as the gasket rubber, and in the unvulcanized state, the entire gasket surface or most of the gasket surface is high. It allowed crimping unvulcanized rubber stiffness rubber, to integrate by vulcanization. KoTsuyoshi resistant rubber <br/> beam is identical to inner rubber main component, nylon, chemical fiber or diameter of the synthetic resin 20μm such as polyester or aramid, a length of the short fibers within 30 mm 0.5 to 3
The rubber vulcanizing agent containing 0 parts of the rubber is mixed in an amount of 0.5 part or more and less than 5 parts with respect to the number of parts of the rubber on the inner surface of the hose, and simultaneously vulcanized and bonded.

The inner rubber generally has a hardness of 50 ° to 50 °.
70 ° rubber is used, but this is a flat gasket.
When used as a tortoise, its compression surface pressure is 60 kgf /
cm ²When, the pressure for stable sealing is 1/3 of that.
20 kgf / cm²Is the limit. On the other hand these soft
Quality rubber is 60kgf / cm²When the surface pressure of
The maximum strain reaches 200% -300%, the breaking strain of rubber
Is close to 400%. Tightened many times
If you use it in a place with large pressure fluctuations, the rubber will finally
It breaks and loses its sealing ability. Prevent this
As a method, to make the inner rubber high hardness to reduce distortion
The flexible part of the hose that requires flexibility
Would be hard, which is not desirable.
Also, as described above, add asbestos to the gasket part.
Tighten or attach asbestos with some kind of adhesive
The same material as the inner rubber can be used for those joined using
The pressure (tightening surface pressure) applied to the formed gasket is
It does not change, and the strain rate for the rubber itself decreases.
Not something.

In the method of the present invention, the most important point is that a high-rigidity rubber whose main component is the same as the inner surface rubber is integrally added to the entire surface or most of the surface of the gasket rubber continuously formed from the inner surface rubber. vulcanization Ru near be wearing.

[0007]

DETAILED DESCRIPTION OF THE INVENTION The present invention will now be described with reference to the drawings.
The details will be described. In FIG. 1, 1 is an inner rubber, 2 is a supplement
Strong cord, 3 is outer rubber, 4 is flange, 6 is high rigidity rubber
It is. As shown in Fig. 1, the fiber itself is mixed with short fibers to withstand high compression surface pressure, and the vulcanizing agent of the high rigidity rubber is made larger than the compounding amount of the inner surface rubber, so that vulcanization is performed. That is, the vulcanizing agent migrates to the inner surface rubber to make it highly rigid. The compressive strain of the gasket decreases as the hardness of the rubber increases. There are two methods of increasing the hardness: a method of increasing the vulcanizing agent of rubber to increase the degree of vulcanization and a method of increasing the filler. The former has higher hardness but loses elasticity, and uneven surface pressure tends to occur due to uneven tightening of the flange. Further, when increasing the degree of vulcanization, it is necessary to use 5 to 10 parts of a large amount of vulcanizing agent, and mixing and dispersion are likely to be inhomogeneous. On the other hand, in the method of using a large amount of filler, in addition to losing elasticity, there is an upper limit of its hardness, and it is not always possible to withstand the surface pressure that maintains the sealing property at high pressure. That is,
The high-rigidity rubber in the gasket receives a large surface pressure, and these act on the inner rubber side where the degree of vulcanization decreases in sequence, so that a large amount of strain does not occur locally and sealing performance at a high surface pressure is achieved. To hold. The short fibers mixed in the high-rigidity gasket rubber do not limit the material, but if the diameter is too large, there is a great risk of fluid leakage , and it is difficult for the short fibers to be evenly dispersed in the rubber. Further, its length does not have to exceed the thickness generally used as a gasket. When using short fibers having a relatively long length, it is necessary to increase the number of mixed parts, but long fibers have sufficiently high rigidity even if the mixed amount is small. The pressure to seal the fluid is 20 kgf / cm ²
When, the surface pressure acting on the gasket is 100 kgf / c
Although the m ^2, it is desirable that the fiber diameter when the 0.3 to 5 m, a length mixed 3-10 parts ones 50 microns and 500 microns, the fiber diameter is 2Myuemu～8myuemu, length 3m
It is desirable to mix 0.5 to 3 parts when using m. As described above, the fiber diameter, the length thereof, and the mixing amount are correlated with each other, and when the sealing pressure is increased, the fiber diameter, the length, and the mixing amount may be further increased.

The present invention will be described by way of examples. In FIG. 2, a round steel ring 5 is crimped with a JIS 10 kgf / cm ² 100A flange 4, and the reinforcing cord 2 surrounds the ring. The parts are joined by sufficient vulcanization. The proof cord has a withstand pressure of 100 kgf /
It should be at least cm ² .

In FIG. 2, 1 is an inner rubber, and 2 is a reinforcing core.
, 3 is an outer rubber, 4 is a flange, and 5 is a steel ring . φD = 140 mm, φd = 100 mm, t = 4
T = 2. However, it is not limited to this,
It is only an example.

[0010] Figure 3 is a 2mm thickness thereof in that arranged high stiffness rubber on the end of FIG. However, the total thickness of the gasket portion t does not change. All are simultaneously vulcanized together.

FIG. 4 shows the structure of FIG. 2 in which the ring shape is square.

FIG. 5 shows a high-rigidity rubber disposed at the end of FIG.

As an example, the formulations of FIGS.         Inner rubber compound         Natural rubber 100         HAF carbon black (Tokai Carbon Co., Ltd.) 50         Process oil 10         Stearic acid 2         Zinc flower No. 1 5         Vulcanization accelerator OBS (Ouchi Shinko) 1.0         Sulfur 1.5     ─────────────────────────────                                                 169.5

Compounding of high rigidity rubber Natural rubber 100 HAF carbon black 50 Process oil 10 Stearic acid 2 Zinc flower No. 1 5 Vulcanization accelerator OBS 1.0 Sulfur 3.0 Short fiber * 1 3.0 * 1 Short fiber is A product having a length of 1 mm and a diameter of 2 μm was used. The material is nylon.

The vulcanization conditions are 160 ° C. and 45 minutes.

The number of times until water started to leak from the gasket part was measured. The results are shown in Table 1 .

[0017]

[Table 1] When 10 kgf / cm ² Example FIG. 3 / Example FIG. 2 = 16.25 Example FIG. 5 / Example FIG. 4 = 20.2 When 20 kgf / cm ² Example FIG. 3 / Example FIG. 2 = 18. 1 Example FIG. 5 / Example FIG. 4 = 23.7

Those having high-rigidity rubber have durability of several tens of times in spite of the change of the end face shape.
When water started to leak, the gasket was in a broken state.

Similar evaluations were made for the products of Example 2 and Example 4 and the results shown in Table 2 were obtained when an asbestos-made gasket was attached to the entire gasket surface.

For the asbestos, a dragonfly # 100 (manufactured by Nichias) t = 2 mm was used, and for bonding the asbestos and the rubber, Konishi (manufactured by Konishi) epoxy bond was used. In either case, the rubber gasket is broken when water begins to leak. The non-adhesive asbestos has the opposite effect, and the effect in the case of adhesion is slightly larger.

[0021]

The rubber gasket-integrated hose has a drawback that when it is tightened with a high surface pressure, the hose is greatly deformed and is damaged very early when the pressure fluctuation is large. The method can be used without damage for a long period of time. Especially when used in a pump line where start-up and stop are severe or in a place where the pumping distance varies, its long-term durability is extremely significant. Also, when the hose is moved to various places and flange fastening is performed each time, there is little risk of damages due to fluctuations in the fastening load and over tightening. In addition, since it is not necessary to provide a special gasket, it is possible to provide a highly durable rubber hose that is inexpensive and easy to handle.

[Brief description of drawings]

FIG. 1 is a schematic sectional partial view of the present invention.

FIG. 2 is a schematic partial sectional view of FIG.

FIG. 3 is a schematic partial sectional view of FIG.

4 is a schematic partial sectional view of FIG.

5 is a schematic partial sectional view of FIG.

FIG. 6 is a schematic sectional partial view of a conventional technique A.

FIG. 7 is a schematic sectional partial view of a conventional technique B method.

FIG. 8 is a schematic sectional partial view of a modified C method of the prior art B method.

[Explanation of symbols]

1 inner rubber 2 reinforcement cord 3 outer rubber 4 flange 5 steel ring 6 High rigidity rubber 7 gasket 8 Nipple part

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI B29L 31:24 F16L 23/02 D (56) References Showa 54-22219 (JP, U) Showahei 3-94491 ( (58) Fields investigated (Int.Cl. ⁷ , DB name) F16L 23/16 B29C 65/70 B29D 31/00 B29K 21:00 B29K 105: 12 B29L 31:24

Claims (3)

(57) [Claims] 1. An inner surface rubber for sealing a fluid in a rubber hose or a rubber joint is a gasket rubber integrated with a flange.
On the entire surface or most of the surface of the gasket rubber ,
A gasket- integrated type flange joint having a structure in which a high-rigidity rubber having the same main component as this gasket rubber and having an improved compression rigidity is vulcanized and adhered , wherein the high-rigidity rubber is made of nylon, polyester or aluminum alloy.
Diameter less than 20μm and length less than 30mm
A gasket-integrated flange joint , characterized in that 0.5 to 30 parts of short fibers are mixed . 2. The hardness of the inner rubber is 50 to 70 °.
The vulcanizing agent and vulcanization accelerator contained in the high rigidity rubber
A large amount of the propellant is blended with respect to the blending number of the inner rubber.
And is integrated with the inner rubber from the high rigidity rubber side.
The rigidity gradually decreases toward the gasket rubber side.
The gasket-integrated flange joint according to claim 1, wherein the flange joint is formed as follows . 3. The gasket according to claim 1 or 2.
A method of manufacturing an integral flange joint, the method comprising:
If the hardness after vulcanization is 50 to 70 °,
To 0.5 parts or less with respect to the compounded part of the inner rubber the amount of vulcanizing agent and the vulcanization accelerator of KoTsuyoshi resistant rubber with enhanced compressive stiffness
A method for manufacturing a gasket-integrated type flange joint, which comprises increasing the amount of less than the upper 5 parts and simultaneously performing vulcanization adhesion.