JP6895174B2 - Fluid shutoff airbag - Google Patents

Description

The present invention relates to a fluid shutoff airbag that is inserted into a pipeline such as gas or water and sewage and temporarily shuts off the fluid flowing in the pipeline.

Patent Document 1 discloses an airbag for a blocking device including an interior bag made of rubber and an outer bag made of cloth having an elastomer layer formed on an outer peripheral portion in close contact with the inner surface of a pipeline. In such an airbag, as the inner bag expands due to the compressed air sent from the outside, the outer bag also expands, and the outer bag adheres to the conduit through the elastomer layer.

JP-A-2017-57996

By the way, the airbag described in Patent Document 1 is used when the pipeline is closed in a state where a fluid flows in the pipeline or when the inside of the pipeline is blocked in a state of atmospheric pressure or residual pressure. In the former case, the airbag is used in a state where the fluid pressure and the pressure of the compressed air sent to the interior bag are balanced, but in the latter case, the cutoff in the previous process is released and the inside of the pipeline is removed. The air pressure inside the airbag is set so that the cutoff can be maintained even when the pressure is high, but when the pressure inside the airbag is atmospheric pressure or residual pressure, the air pressure inside the airbag and the conduit are The pressure inside was not balanced, and there was a risk that the airbag would expand excessively and excessive tensile tension would act on the outer bag, causing the outer bag to tear.

Therefore, there arises a technical problem to be solved in order to safely shut off the pipe regardless of the pressure state in the pipeline, and an object of the present invention is to solve this problem.

In order to achieve the above object, the fluid blocking airbag according to the present invention is a fluid blocking airbag that temporarily shuts off the fluid in the pipeline, and the base material bag and the base material bag are described above. A reinforcing woven fabric is provided on the base material bag so as to include at least a non-supported region of the base material bag that is not supported by the pipe line when expanded in the pipe line.

According to this configuration, the reinforcing woven fabric restricts excessive expansion of the non-supported region of the base material bag that does not adhere to the pipeline from the outer peripheral side of the base material bag, thereby suppressing damage to the base material bag. can do.

Further, in the fluid blocking air bag according to the present invention, one of the warp direction or the weft direction of the base material bag, which exhibits high tensile strength, is set along the longitudinal direction of the conduit, and the reinforcing woven fabric is set. It is preferable that one of the warp direction or the weft direction showing high tensile strength is provided along the circumferential direction of the conduit.

According to this configuration, one of the warp and weft directions of the reinforcing woven fabric, which shows high tensile strength, coincides with the warp or weft direction of the base material bag, which shows low tensile strength. The woven fabric can prevent the supported area of the base material bag from expanding excessively.

Further, in the fluid blocking airbag according to the present invention, the reinforcing woven fabric is continuously provided at the tip portion capable of adhering to the inner surface of the pipeline and the tip portion, and the base material bag is expanded. It is preferable that the hose is provided with a mouth portion that is restrained via caulking.

According to this configuration, the tip portion that is in close contact with the inner surface of the pipeline and the mouth portion that is restrained by caulking can be integrally formed, and the sewing points where tensile stress tends to be concentrated when the bag is expanded can be reduced. it can.

Further, it is preferable that the fluid blocking airbag according to the present invention has a slit in which the mouth portion is formed in a substantially bow shape from the end portion on the mouth side toward the tip side.

According to this configuration, when the mouth part is sewn in a circular shape, the volume of the base material bag and the reinforcing woven cloth is reduced by the amount of the slit, so that the mouth part is strengthened by caulking with a small diameter. Can be externally crimped to.

In the fluid blocking airbag according to the present invention, the reinforcing woven fabric is a base material because it regulates excessive expansion of the non-supported region of the base material bag that does not adhere to the pipeline from the outer peripheral side of the base material bag. Damage to the bag can be suppressed.

A front view and a side view showing a state in which a fluid blocking airbag according to an embodiment of the present invention is expanded to block the fluid flowing in a pipeline. Partially omitted development view of the fluid shutoff airbag.

An embodiment of the present invention will be described with reference to the drawings. In the following, when referring to the number, numerical value, quantity, range, etc. of components, it is limited to the specific number unless it is clearly stated or in principle it is clearly limited to the specific number. It is not a thing, and it may be more than or less than a specific number.

In addition, when referring to the shape and positional relationship of components, etc., unless otherwise specified or when it is considered that this is not the case in principle, those that are substantially similar to or similar to the shape, etc. shall be used. Including.

In addition, the drawings may be exaggerated by enlarging the characteristic parts in order to make the features easy to understand, and the dimensional ratios and the like of the components are not always the same as the actual ones. Further, in the cross-sectional view, hatching of some components may be omitted in order to make the cross-sectional structure of the components easy to understand.

FIG. 1 is a diagram showing a state in which a fluid blocking airbag (hereinafter, simply referred to as “airbag”) is inflated in a pipeline, and FIG. 1 (a) is a front view seen from the direction of the pipe axis. Yes, FIG. 1 (b) is a side view of FIG. 1 (a).

The airbag 1 is used to temporarily shut off the fluid flowing in the pipeline during repair or replacement work involving cutting of the pipeline.

The pipeline is a polyethylene conduit (hereinafter referred to as “gas pipe 2”) corresponding to the gas of medium pressure B. The fluid flowing in the pipeline is not limited to gas, and may be clean water or sewage. The material of the pipeline may be cast iron, steel, or the like, in addition to polyethylene.

A hose 3 for feeding compressed air into the airbag 1 is connected to the mouth of the airbag 1. A caulking ring 4 is externally crimped to the connection portion between the airbag 1 and the hose 3, and the airbag and the hose 3 are integrated. The hose 3 is a flexible rubber tube having a predetermined length. The caulking ring 4 is made of metal and is formed in an annular shape, and can be deformed in diameter by using a crimping tool or the like.

The airbag 1 includes an interior bag 10, an exterior bag 20 as a base material bag, and a reinforcing woven cloth 30.

The interior bag 10 is formed in a long spherical shape, and the mouth is formed by narrowing one end side. The interior bag 10 is made of rubber such as natural rubber.

The outer bag 20 has a mouth formed by narrowing one end side, accommodates the inner bag 10 so as to cover it, and expands as the inner bag 10 expands. The outer bag 20 and the reinforcing woven cloth 30 are made of, for example, polyester cloth, and are formed by plain weaving a multifilament.

The reinforcing woven fabric 30 is provided on the outside of the primary side (mouth side) of the exterior bag 20. In the reinforcing woven fabric 30, the tip portion 31 described later is in close contact with the inner surface of the gas pipe 2. Further, in the reinforcing woven fabric 30, the mouth portion 32, which will be described later, is integrated with the hose 3 via the caulking ring 4. The airbag 1 may be fed into the gas pipe 2 so that the mouth side faces the secondary side.

FIG. 2 is a developed view of the exterior bag 20 and the reinforcing woven fabric 30 before sewing, omitting a part of the secondary side (tip side) of the exterior bag 20.

The reinforcing woven fabric 30 is formed to have substantially the same shape as the outer bag 20 from the end on the mouth side to the vicinity of the center. The reinforcing woven fabric 30 includes a tip portion 31 and a mouth portion 32.

The tip portion 31 is a portion that comes into close contact with the inner circumference of the gas pipe 2 when the airbag 1 expands. The tip portion 31 is provided with an elastomer layer (not shown). The elastomer layer is formed from the front surface to the back surface of the tip portion 31, and is formed by, for example, impregnating the tip portion 31 with an elastomer. The elastomer constituting the elastomer layer is a substance having elasticity at room temperature, for example, polyurethane elastomer, modified silicone resin, silicone resin, silicone rubber, etc., which is soft and elastic, and has airtightness and abrasion resistance. ing.

The elastomer layer provided on the surface of the tip portion 31 is compressionally deformed when the tip portion 31 is pressed against the inner surface of the gas pipe 2, deforms according to the unevenness of the inner surface of the gas pipe 2, and the gas pipe is deformed by its restoring force. It is in close contact with the inner surface of the gas pipe 2 so as not to generate a minute gap between the gas pipe 2 and the inner surface of the gas pipe 2.

Further, the elastomer layer provided on the back surface of the tip portion 31 is compressed and deformed when the tip portion 31 is pressed against the inner surface of the gas pipe 2, and is deformed following the fine irregularities on the surface of the exterior bag 20 to be deformed to follow the fine irregularities on the surface of the exterior bag 20. It adheres to the surface of the outer bag 20 so as not to generate a minute gap with the surface of the outer bag 20.

The mouth portion 32 is a portion that is crimped to the hose 3 by the caulking ring 4. Further, the mouth portion 32 is located outside the non-supported region that is not supported by the gas pipe 2 when the outer bag 20 expands in the gas pipe 2. That is, the mouth side of the mouth portion 32 is crimped to the caulking ring 4, and the tip end side of the mouth portion 32 covers the non-supporting region of the outer bag 20. The airbag 1 is formed by integrally forming a tip portion 31 that adheres to the inner surface of the gas pipe 2 and seals between the gas pipe 2 and the outer bag 20 and a mouth portion 32 that is restrained by the caulking ring 4. It is possible to reduce the number of sewn areas where tensile stress tends to concentrate during expansion.

Slits 40 are provided at the mouth side ends of the outer bag 20 and the mouth portion 32. The slit 40 is formed in a substantially bow shape from the mouth side end portion of the mouth portion 32 toward the tip end side. The region of the mouth portion 32 provided with the slit 40 is crimped to the caulking ring 4.

When the end portion of the outer bag 20 and the mouth portion 32 on the mouth side is sewn, the volume of the outer bag 20 and the reinforcing woven cloth 30 is reduced by the amount of the slit 40 provided. The outer bag 20 and the mouth portion 32 may be integrated by a method other than sewing. As a result, the mouth portion 32 can be fitted externally with the small-diameter caulking ring 4, and the airbag 1 and the hose 3 can be firmly integrated.

The two-dot chain line in FIG. 2 indicates the sewn position on the tip side and the circumferential direction of the outer bag 20 or the reinforcing woven fabric 30. In the circumferential direction of the outer bag 20 and the reinforcing woven cloth 30, the ends in the vertical direction of the paper surface of FIG. 2 are sewn together.

The outer bag 20 and the reinforcing woven fabric 30 are set so that the tensile strength in the warp direction is about 30% larger than the tensile strength in the weft direction. The warp direction D1 of the outer bag 20 is set in the left-right direction in FIG. 2 and coincides with the pipe axis direction of the gas pipe 2. Further, the warp direction D2 of the reinforcing woven cloth 30 is set in the vertical direction of FIG. 2 and coincides with the circumferential direction of the gas pipe 2. That is, the warp direction of the reinforcing woven cloth 30 and the weft direction of the outer bag 20 coincide with each other. As a result, the reinforcing woven fabric 30 regulates the unsupported region of the exterior bag 20 that does not adhere to the gas pipe 2 from being excessively expanded from the outer peripheral side of the exterior bag 20.

In this way, the airbag 1 according to the above-described embodiment prevents the reinforcing woven fabric 30 from excessively expanding the non-supported region of the exterior bag 20 that does not adhere to the gas pipe 2 on the outer peripheral side of the exterior bag 20. Since it is regulated from the above, damage to the outer bag 20 can be suppressed.

In addition to the above, the present invention can be modified in various ways as long as it does not deviate from the spirit of the present invention, and it is natural that the present invention extends to the modified ones.

1 ・ ・ ・ Airbag 2 ・ ・ ・ Gas pipe 3 ・ ・ ・ Hose 4 ・ ・ ・ Caulking 10 ・ ・ ・ Interior bag 20 ・ ・ ・ Exterior bag (base material bag)
30 ・ ・ ・ Reinforcing woven cloth 31 ・ ・ ・ Tip 32 ・ ・ ・ Mouth 40 ・ ・ ・ Slit

Claims (3)

A fluid blocking airbag that temporarily blocks the fluid in the pipeline.
Base bag and
The shape of the base material bag is formed to be substantially the same as the shape from the end on the mouth side to substantially the center, and when the base material bag expands in the pipeline, it is not supported by the pipeline of the base material bag. A reinforcing woven fabric outerized on the base bag so as to include at least a non-supporting area,
With
One of the warp or weft directions of the base material bag, which exhibits high tensile strength, is set along the longitudinal direction of the pipeline.
A fluid blocking airbag, characterized in that one of the warp and weft directions of the reinforcing woven fabric, which exhibits high tensile strength, is provided along the circumferential direction of the pipeline. The reinforcing woven fabric is
A tip that can be in close contact with the inner surface of the pipeline,
A mouth portion that is continuously provided at the tip portion and is restrained by a hose that inflates the base material bag via caulking.
The airbag for fluid shutoff according to claim 1, wherein the airbag is provided. The fluid blocking airbag according to claim 2, wherein the mouth portion includes a slit formed in a substantially bow shape from the mouth side end portion toward the tip end side.

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